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How To Roast Red Peppers

partysugar — Mon, 07 May 2007 05:58:32 -0700

Roasted red bell peppers are a great addition to salads, sandwiches, pasta dishes, and antipasto platters. I love to make my own at home, jar them and have them on hand for whenever one strikes my fancy. Large red bell peppers are sweet, not spicy and can be found in grocery stores year round - although their peak season (when they are the cheapest) is from May until August. To roast, start by washing the peppers and removing the stickers. Next you can either char them on high heat on a gas range stove by placing them directly onto the grates or roast them in the oven (which is what I like to do). Use tongs to turn the pepper to blacken on all sides. Cook on the grill the same way. If roasting in the oven, preheat to 450F. Arrange the peppers on a cookie sheet and roast in the oven, turning every 15 minutes until done (about 30 minutes). Whatever technique you use to blacken the peppers, once they are done place in a covered bowl or brown paper bag. As the steam from the peppers condenses, the skin becomes easier to peel off.

Once the peppers have cooled, carefully peel off the blackened skin and discard. You can do this with your fingers or a sharp pairing knife. Pull or cut off the top of the pepper and squeeze gently to remove the seeds. Never rinse or wash the peppers as the water will diminish the smoky flavor. When the skins and seeds have been removed cover them in oil, adding garlic slices or herbs if desired and refrigerate for up to 2 weeks.

Bobby Flay's Sandwich Tips

partysugar — Fri, 10 Apr 2009 08:00:01 -0700

Yesterday we brought you a fun little video of Bobby Flay making sandwiches, and today we've got his tips for crafting the best 'wich! While Flay is known for his superior grill skills, he's also a sponsor for Best Foods mayonnaise and a master of sandwich making. Here's how the Iron Chef recommends building a better sandwich:

When a sandwich contains several moist ingredients (mayonnaise, tomatoes, etc), use a thick, crusty bread like ciabatta.
When putting together a simple sandwich with fewer ingredients, like ham and cheese, select thinly sliced bread.

Get the rest of Flay's fabulous suggestions when you read more.

For sandwiches on the go, separate the elements: Put the bread in one baggy, the condiments in a small Tupperware or squirt bottle, and the veggies in another baggy. Assemble just before eating.
Get creative! Instead of using lettuce, opt for other crunchy vegetables. When they come in contact with oil-based condiments, sliced cucumber and fennel won't wilt or turn soggy.
Add a kick to any sandwich with strong flavors like smoked Spanish paprika, fresh ground black pepper, chili powder, or fresh lime juice.
Make sure your sandwich is full of color. Incorporate fresh vibrant elements such as parsley leaves, finely diced red onions, or green, yellow, and red peppers.
Don't forget to have fun with your ingredients! Who says you can’t enjoy the crunch of blue corn chips on your sandwich? Why not include chopped toasted walnuts or pecans? How about dried cranberries, cherries, or raisins? The sky is the limit.
Think outside the box. By adding a creamy lemon-chive vinaigrette, you can take the classic egg sandwich from breakfast to dinner.
Make your own custom sauces. Jazz up store-made condiments with fresh herbs, citrus juice, horseradish, roasted tomatoes, olives, or chiles.

How do you make the ultimate sandwich? Share your tips with us below!

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Simple Tip: Peeling Roasted Red Peppers

YumSugar — Thu, 28 Feb 2008 07:01:51 -0800

I absolutely adore using roasted red peppers to add a gourmet touch to sandwiches, salads, and all sorts of entrees. I already gave you a primer on how to roast red peppers, but lately I've been using this easy tip for peeling them that I wanted to share.

You can roast peppers several different ways: I prefer to coat mine lightly with olive oil and blacken them in the broiler for five to 10 minutes. No matter what your method, this trick gets the blackened skins off easily. To find out how, read more.

Remove the peppers from the oven and place them on a flat surface with an overturned bowl on top, so it completely covers the peppers. The bowl will trap the heat from the peppers and fill with steam. This "steaming" process will loosen the skins so that they peel off easily.

After five to 10 minutes, remove the bowl, turn it right side up, and place it on your prep surface. Carefully peel the skins off of the peppers and drop the discarded skins into the bowl. Then, you can just toss the skins in the trash.

Do you have an easy way for peeling peppers? Let us know below!

'Wich of the Week: Chickpeas and Red Peppers at 'Wichcraft

YumSugar — Wed, 15 Apr 2009 14:00:40 -0700

When it comes to expensive sandwiches, I'm rarely disappointed with 'Wichcraft. Though the creations are somewhat pricey, they're also well-made, and when the ingredients are surprising, I'll totally shell out the cash. Though now that 'Wichcraft's Tom Colicchio and Sisha Ortuzar have released a cookbook, I can save my money and make the recipes at home. Lucky for you, I just got my hands on the cookbook, and I have the recipe for the latest 'wich I grabbed at 'Wichcraft: the reasonably priced ($6.95) chopped chickpeas with roasted red peppers, black olives, lemon confit, and parsley on country bread. Though I love the anchovy and egg sandwich with a consuming passion, I decided to try something new on my last trip, and I wasn't disappointed. To find out how to make it, read more.

The country bread that 'Wichcraft uses is just perfect: crusty on the outside but with a soft, friendly give. I thought "chopped chickpeas" would just mean hummus, so I was pleasantly surprised by this spread, which is really more of a chickpea salad. Though making the chickpeas and lemon confit from scratch sounds like a lot of trouble, it could also be done far in advance, and the sandwich itself is quite simple.

Chopped Chickpeas Sandwich With Roasted Red Peppers, Black Olives, Lemon Confit, and Parsley
From 'Wichcraft: Craft a Sandwich Into a Meal - and a Meal Into a Sandwich

Ingredients

2 cups marinated chickpeas
8 slices country bread
1/2 cup roasted red peppers
4 tablespoons pitted and chopped Nicoise olives
12 slices lemon confit
1 cup flat-leaf parsley leaves
Freshly ground black pepper

Directions

In a food processor, coarsely chop the marinated chickpeas, until they're spreadable but still chunky. Evenly spread the chickpeas over 4 of the bread slices.
Top with the roasted peppers, olives, lemon confit, and parsley, in that order, and season with pepper.
Top with the remaining 4 slices of bread, cut into halves, and serve.

Makes 4 sandwiches.

Print recipe with images | without images

Recipe Ideas For A Winter Party

DearSugar — Sat, 18 Nov 2006 13:00:00 -0800

Dear Sugar
I am planning to throw a holiday dinner party at my home for eight friends in the beginning of December. Do you know of any delicious warm winter meals that I can serve that are relatively easy to cook? I work full time and will be able to get out early but will only have about an hour and a half to prepare. Hostess Hope

To see DEARSUGAR's answer read more

Dear Hostess Hope,
This wonderfully delicious, four course meal is both easy and impressive. Your guests will leave with a satisfied belly that will make them think you've slaved for days preparing. Set the table nicely and add a festive gourd or colorful and prearranged flower centerpiece to the center of the table. Also, don't forget to serve water. It's important to drink and it will also help to fill everyone up! Here's everything you will need and how to do it. Bon Appetit.

APPETIZER: BEET, GOAT CHEESE & ARUGULA SALAD
1/4 cup balsamic vinegar
3 tbsp thinly sliced shallots
1 tbsp honey
1/3 cup olive oil
6 beets, cooked and quartered (yellow or red)
6 cups fresh arugula
1/2 avocado, peeled, pitted, and cubed
3 oz crumbled goat cheese
Add salt and pepper to taste

PREPARE AND COOK:
Preheat the oven to 450 degrees. Line a baking sheet with tin foil and foil. Whisk the honey, balsamic vinegar and the shallots together in a separate bowl. As you are whisking, add in the oil slowly. Add a dash of salt and pepper to taste. Place the beets in another bowl with some of the dressing and then put them on the baking sheet to roast for 12 minutes. Stir them occasionally and them set them aside to cool. Next, stir the arugula in a bowl with some vinaigrette. Pre-plate the salad and arrange the beets around the greens when cool. Lastly sprinkle the cheese and the avocado on top.

*Serves four, so double the recipe for eight people.

ENTREE: HONEY SPICED GLAZED CHICKEN

1/4 cup honey
2 garlic cloves
2 tablespoons fresh lemon juice
1 tsp paprika
1 tsp brown sugar
2 tsp dijon mustard
1/2 cayenne pepper
4 chicken breasts cut in half on the bone with the skin on. (about 10 oz)
Add salt and pepper to taste

PREPARE AND COOK:
Preheat oven to 425 degrees. In a small bowl, mix the honey, garlic, lemon juice, brown sugar, mustard paprika and cayenne pepper together. Place chicken on a baking sheet and with a sharp knife, put 2 deep slits into each breast. Sprinkle salt and pepper on top of the raw chicken and then use a brush to spread 2/3rds of the honey mixture evenly on top. Bake for 15 minutes.

At this time, brush on the remainder of the glaze on top of the semi-cooked chicken and bake again for another 10-12 minutes. Then preheat the broiler. Take the chicken out of the oven and pour the juices from the baking sheet onto the chicken and place it inside the broiler for 1-2 minutes until the skin is nice and crispy. Serve immediately.

*Serves four, so double the recipe for eight people.

SIDE DISH: ROASTED HERB RUSSET POTATOES

2 lbs russet potatoes (slice into wedges)
1 1/2 tbsp olive oil
2 tsp chopped oregano
4 minced garlic cloves
8 oz. goat cheese or feta cheese (crumbled)
Add salt and pepper to taste

PREPARE AND COOK:
Preheat oven to 400 degrees. Spread out your sliced potatoes on another baking sheet. Then mix the oil, garlic, oregano, salt and pepper onto them. Roast the potatoes for about 15 minutes until they are browned on one side. Then, flip them over and roast the second side for another 15-20 minutes. They should be golden. Take them out of the oven and sprinkle either the goat or the feta cheese on top.

DESSERT: GOOEY CHOCOLATE WRAPS
1/2 cup almond paste
4 (8-inch) flour tortillas
1 1/4 cup mini-marshmallows
2/3 cup milk chocolate chips
Whipped cream
Vanilla ice cream

PREPARE:
Preheat a grill to low. Spread almond paste evenly on each tortilla. Sprinkle a little bit more than 1/4 cup of marshmallows and a little but more than 1/4 cup of the chocolate chips onto one side of the tortilla. Roll the tortilla up, wrap it in tin foil and it seal tightly. Repeat until all of the tortillas are filled. You can do this the night before so all you have to do is heat them up before dessert. Grill the bundles over low heat for about 5-10 minutes or until they are heated through. Remove foil and place on a plate. Garnish with fresh sweetened whipped cream and vanilla ice cream.

(Recipe is a "Sugarized" version of Paula Deen's).

Healthy Eating Tip: Eat Five Colors a Day

FitSugar — Wed, 18 Mar 2009 08:00:00 -0700

We are more than halfway through March, which is also National Nutrition Month, so hopefully, you all are working hard to eat at least five servings of fruits and veggies daily. Well, I am going to up the ante: Try to eat five different colors fruits and veggies daily.

It is important to eat a rainbow since disease fighting antioxidants also give foods their color. The wider color palate you eat the wider the spectrum of antioxidants, vitamins, and minerals you will be eating. Yep, downing just goji berries or drinking pomegranate juice is really not enough to be considered healthy eating.

To see how I have worked five colors into my meals, read more.

Breakfast: Blue - I throw a half of cup of frozen blueberries onto my morning oatmeal, and while the oatmeal cools the berries thaw.
Snack: Yellow - I like a little tropical fruit salad to get me through until lunch and mix sliced banana with sliced mango.
Lunch: Green - Spinach and arugula salad surely covers me for green.
Dinner: Orange - Roasted yams certainly cover the color orange.
Dessert: Red - Strawberries are at the beginning of their season and sliced or whole they make a wonderful dessert.

It is super easy to add a variety of color to your daily diet, but might require a little planning ahead and thinking back. You can substitute purple cabbage for green, red pepper for green, broccoli for cauliflower, yams for regular spuds . . . you get the point. Tell me below how you work color into your daily diet?

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Taste Test: La Famiglia DelGrosso Pasta Sauce

YumSugar — Wed, 24 Sep 2008 09:00:00 -0700

Since it's easy to prepare and so versatile, I cook pasta at least once a week. Lately, I've been experimenting with various sauces and pasta shapes to see how the factors make a difference in taste, so I gave La Famiglia DelGrosso a try.

I sampled three of eight different sauces, all of which have kitschy titles named after family members. My boyfriend thought Aunt Mary Ann's Sunday Marinara was "light on flavor," but I preferred it to its competitors. A Trader Joe's pomodoro sauce tasted sickly sweet in comparison. Uncle Joe's Vodka Celebration was my favorite of the bunch: the texture was creamy, but the sauce wasn't as light in color as most commercial vodka sauces, which often are too heavy on cream.

The sauce possessed a strong umami quality (incidentally, tomatoes contain high amounts of umami). Uncle Bo's Roasted Red Pepper Tour was made with - you guessed it - roasted red peppers, and it was my sweetie's favorite of the three because of its deep, smoky flavor.

Certainly no commercial variety can replace a homemade pasta sauce, but La Famiglia sauces work in a pinch. They are available at select Whole Foods and other grocers across the country. Have you tried any of the brand's flavors? What did you think of them?

Come Party With Me: Red and Green Themed White Elephant

YumSugar — Fri, 15 Dec 2006 00:08:15 -0800

When I was little, my parents always threw a White Elephant Christmas party. I ran around in my Clara (from the Nutcracker) pajamas and watched quietly as everyone fought over the best gifts. The most memorable parties were the ones when my dad would let me pick his gift. Now that I'm all grown up I'm planning my own version of a White Elephant party with a red and green theme. Not only am I asking guests to bring a wrapped gift, I'm asking them to come dressed in red, green or a combination of both colors. To carry the theme throughout the party, I'm only making red and green food. Wanna host this party too? read more

Definition: For anyone who doesn't know exactly how a White Elephant works, here's a quick definition: a White Elephant is a type of gift exchange in which each guest is asked to bring an anonymous wrapped gift. During the party guests draw numbers to reveal the order in which they select the gifts. The person assigned with #1 picks, unwraps, and displays a gift. Next the person assigned with #2 has the choice to either steal #1's gift (#1 then must select and unwrap a gift from the pile) or open a wrapped gift. For each subsequent number, players can choose between any of the opened gifts or any of the unopened gifts. Read more on how to host a white elephant.

Invites: I am going to create an elephant stencil using the picture of this elephant (I will remove the elephant's tusks because I want a friendly elephant). Next I will cut out elephant shapes on white card stock to create an elephant shaped invite that will fit in a regular 5x7 card envelope. To make him festive you decorate with red and green glitter, sequins, ribbon, shiny paper, and thread. I'm going to give mine a necklace of red and green sequins with red and green thread. I'll make sure to put sequins on both sides of the card, then leave one side blank and put the party information on the other. At the bottom of the invite I'll write, Red and Green Attire Requested, to let guests know I want them to come dressed in bright reds and merry greens. I'll send the invites in red or green envelopes written in contrasting green and red ink.

Menu: Although you may think I'm crazy to create a whole menu with only red and green ingredients it's actually a lot easier than you realize. Tons of foods are red and green. Make three little appetizers for people to nibble on while unwrapping gifts. The first is bruschetta: the red ingredient: tomatoes, the green ingredient: basil. The second is an Italian quesadilla with roasted red peppers. The recipe calls for regular white tortillas but to get a green ingredient I'll substitute green spinach tortillas. The third and final appetizer will be meatballs in a red sauce served with green toothpicks. Put out bowls of red cherry tomatoes and green olives for guests to snack on. Red velvet cupcakes with green frosting (tinted with food coloring) and bowls of red and green M&M's round out the food. Note: Don't arrange all the food on one table, spread it around the room to create a flow for the party that promotes mingling.

Decorations: Red and green everywhere! Red and green candles, plates, napkins and tablecloths. See if you can get a few bouquets of fresh poinsettias-if not, use the fake and sparkly kind to add a super Christmasy feel. Designate a spot for guests to place their presents when they arrive. Write out the number of guests on green paper and place in a Santa hat. Place chairs together to form clusters for guests to sit on during the White Elephant.

Music: Create a red and green play list with a compilation of old and new CDs by Red Hot Chile Peppers, Green Day, or Al Green. Toss in a few Christmas classics like Green Christmas and Rudolph the Red-Nosed Reindeer.

Drinks: Serve Heineken or Heineken Light for green and red wine for red. For a red cocktail make a red apple martini (recipe below), for a green cocktail shake up dead grasshoppers, and for a nonalcoholic option serve Shirley Temples (Sprite with grenadine).

Red Apple Martini
From Instyle (December 2003) magazine

1 cup fresh squeezed lemon juice
1 cup finely crushed candy canes
5 cups vodka
5 cups sour-apple schnapps
7 cups apple juice

Dip martini-glass rims into a bowl of fresh lemon juice, then into a dish of finely crushed candy canes.

Mix vodka, sour-apple schnapps, and apple juice; chill several hours until start of party.

When ready to serve, mix in ice-filled shaker. Pour into glasses; garnish with apple slices.

Serves 20.

Kidney stones

FitSugar — Wed, 08 Oct 2008 17:35:35 -0700

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

New Research:

Patients who have the most common type of gastric bypass surgery, the Roux-en-Y, are at increased risk for kidney stones, beginning 6 months after surgery, according to a study published in 2006.

Causes of Kidney Stones:

Calcium stones form when there is an imbalance in the urine substances that promote and block the formation of stones. Often, the cause of this imbalance is unknown.
Having acidic urine or too much uric acid in the body leads to the formation of uric acid stones.
Struvite stones are almost always caused by urinary tract infections due to bacteria that produce certain enzymes.
Other stones, including cystine and xanthine stones, are usually due to genetic abnormalities.

Treatments:

In about 85% of patients, the kidney stones are small enough that they pass through normal urination, usually within 2 - 3 days.
Certain medications can prevent recurrence of stones in people who are at high risk.
Extracorporeal shock wave lithotripsy (ESWL) is a technique that uses sound waves (ultrasound) to break up simple stones in the kidney or upper urinary tract. The shock waves are delivered from outside the body.
Surgery may be necessary if the stone or stones are too big to pass, and cannot be broken down through ESWL.
A change of diet and increased drinking of fluids, especially water, will help prevent a recurrence.

Introduction

Kidney stones are hard, solid rocks that form in the urinary tract. In many cases, the stones are very small and can pass out of the body without any problems. However, if a stone (even a small one) blocks the flow of urine, excruciating pain may result, and prompt medical treatment may be needed.

The process of urination begins in the kidneys. The kidneys filter out fluids and waste from the body, producing urine. The two kidneys are located deep behind the abdominal organs, below the ribs and toward the middle of the back.

Each kidney contains over a million nephrons. These are the tiny filtration units of the kidney.
Each nephron is composed of a tiny group of blood vessels (a glomerulus) enclosed in a funnel-like structure called Bowman's capsule.
Each glomerulus filters waste products, water, and salts out of the liquid part of the blood (plasma) that has entered the kidney.
About 1% of the plasma is converted into urine. The rest returns into the blood to prevent dehydration. Urine is primarily made of acids, urea, and creatinine (nitrogen compounds).
Urine passes from Bowman's capsule into tiny tubules, which lead to large collecting tubes in the center of the kidney. As the urine passes through this network, it becomes more concentrated.
Urine then flows from the kidney through thin tubes called ureters into the bladder.
The bladder's stretchy walls expand to store the incoming urine until it leaves the body through a tube called the urethra.

The kidneys are responsible for removing wastes from the body, regulating electrolyte balance and blood pressure, and stimulating red blood cell production.

Click the icon to see an image of the urinary tract.

Occasionally, various salts build up on the inside surfaces of the kidney and form crystals. Eventually these crystals become large enough to form stones in the kidney, a condition called nephrolithiasis. Kidney stones (renal calculi) may also form in the ureter or the bladder. Combinations of minerals and other chemicals, some derived from a person's diet, make up the salts in these stones.

Click the icon to see an image of the kidney stones.

Calcium Stones. About 70 - 90% of all kidney stones are made of calcium, usually combined with oxalate, or oxalic acid. A number of common vegetables, fruits, and grains contain oxalate.

About 6% of calcium stones are made of calcium phosphate (called brushite).

Uric Acid Stones. Uric acid is responsible for close to 10% of kidney stones. It is the breakdown product of purines, nitrogen compounds found in our bodies and in certain foods. The breakdown of purines to uric acid occurs in the liver, and from there uric acid enters the bloodstream, most of it passing into the kidneys. From the kidneys, uric acid leaves the body in the urine. Often, uric acid stones occur with calcium stones.

Struvite Stones. Struvite stones are made of magnesium ammonium phosphate. They are almost always associated with certain urinary tract infections. Worldwide, they make up to 30% of all kidney stones. In the United States, however, less than 15% of all stones are struvite. Most struvite stones occur in women. The rate of these stones may be declining in America, perhaps because of better control of urinary tract infections.

Cystine Stones. A build-up of the amino acid cystine, a building block of protein, causes 1% of kidney stones in adults and up to 8% of stones in children. The tendency to form these stones is inherited. Cystine stones are marked by rapid growth and recurrence, which, if not treated promptly, can eventually lead to kidney failure.

Xanthine Stones. Other kidney stones are composed of xanthine, a nitrogen compound. These stones are extremely uncommon and usually occur as a result of a rare genetic disorder.

Click the icon to see an animation about kidney stones.

Causes

The key process in the development of kidney stones is supersaturation.

The urine carries salts, including calcium oxalate, uric acid, cystine, or xanthine.
These salts can become extremely concentrated if there is not enough urine, or if unusually high amounts of crystal-forming salts are present.
When salt concentration levels reach the point at which they no longer dissolve, these salts form crystals.

Different factors may be involved in either reducing urine amount, or increasing the levels of the salts.

Deficiencies in Protective Factors. Normally, urine contains substances that may protect against stone formation, including:

Magnesium
Citrate
Pyrophosphate
Enzymes

These substances:

Allow salt in the urine to be at higher-than-normal concentrations without forming crystals
Prevent crystal formation
Coat the crystals and prevent them from sticking to the surface of kidney tubes

Not having enough of these protective substances can cause stones.

Changes in the Acidity of the Urine. Changes in the acid balance of the urine can affect stone formation.

Uric acid and cystine stones mainly form in acidic urine.
Calcium phosphate and struvite stones increase in alkaline urine.

Factors that Bind Crystals to the Kidney Tubules. Researchers are studying the cells lining the kidney tubules in order to understand how and why early crystals bind to the tubes long enough to form stones. Under investigation are elevated levels of substances that either cause crystals to stick to the tubes or deficiencies in those that prevent them from sticking.

In general, calcium stones form when there is an imbalance in the urine substances that promote and block the formation of stones. Often, the cause of calcium stones is not known, and the condition is then called idiopathic nephrolithiasis. Research suggests that nearly all stones result from problems in the breakdown and absorption of calcium and oxalate. Genetic factors may play a role in about half of these cases. A number of medical conditions and drugs can also affect digestion and intestinal absorption.

Excess Calcium in the Urine (Hypercalciuria). Hypercalciuria (too much calcium in the urine) is responsible for as much as 70% of calcium-containing stones. A number of conditions may produce hypercalciuria. Many are due to genetic factors, but most cases are idiopathic (due to unknown causes).

The following can lead to hypercalciuria and calcium stones:

Too much calcium absorption in the intestines: In most of these conditions, genetic factors lead to increased calcium absorption in the intestine. Researchers are investigating a possible defective gene that regulates calcitriol, a form of vitamin D, which, in excess levels, may increase intestinal absorption of calcium.
Excessive chloride: Chloride has a negative charge, and calcium has a positive one, so they balance each other in the body. Excess chloride may lead to excess calcium. A gene known as CLCN5, which regulates chloride in the urine, is defective in many patients with calcium stones.
Renal calcium leak: In this condition, the filtering processes in the kidney fail, causing an increase of calcium in the urine.
Excessive sodium: High urinary levels of sodium result in increased levels of calcium. Certain defects in the kidney tubules transport system, which cause imbalances in sodium and phosphate, can lead to high calcium levels in the urine. A diet high in salt can also produce this effect.

Excess Oxalate in the Urine (Hyperoxaluria). Oxalate is the most common stone-forming compound. Excessive oxalate in the urine (hyperoxaluria) is responsible for up to 60% of calcium stones and is a more common cause of stones than too much calcium in the urine.

Hyperoxaluria can be either primary or secondary.

Primary hyperoxaluria is an inherited disorder in which too much oxalate in the urine is the main problem.
Secondary hyperoxaluria results from specific conditions that cause high levels of urinary oxalate.

Secondary hyperoxaluria is usually caused by too much dietary oxalates (found in a number of common vegetables, fruits, and grains) or by problems in the body's breakdown of oxalates. Such defects may be due to various factors:

Severe vitamin B6 deficiencies (usually due to genetic disorders)
Deficiencies in Oxalobacter formigene, an intestinal bacteria that breaks down oxalate
Short bowel syndrome, a condition that makes the intestines unable to properly absorb fat and nutrients; calcium may bind to unabsorbed fat instead of oxalates, which causes a buildup of oxalate
Androgens (male hormones)

Female hormones (estrogens) actually lower the risk of hyperoxaluria. Estrogen may help prevent the formation of calcium oxalate stones by keeping urine alkaline, and raising protective citrate levels.

A study published in 2006 found that patients who undergo the most common gastric type of bypass surgery, the Roux-en-Y, were at increased risk for calcium oxalate kidney stones, beginning 6 months after surgery. The study found that patients who underwent the procedure developed hyperoxaluria, and the condition was common 12 months after surgery. The authors also noted an increased number of kidney stone incidents in this patient group.

Excessive Calcium in the Bloodstream (Hypercalcemia). Hypercalcemia generally occurs when bones break down and release too much calcium into the bloodstream. This is a process called resorption. It can occur from a number of different diseases and events:

Hyperparathyroidism: Overactive parathyroid glands cause about 5% of calcium stones. People with this disorder have at least a 20% chance of developing kidney stones. Women are more likely to have this disorder than men.
Immobilization: Lack of movement can lead to kidney stones.
Renal tubular acidosis: This disorder causes acidic and alkaline imbalance. Renal tubular acidosis not only increases calcium levels in the bloodstream but also reduces protective citrate levels.

Hyperuricosuria is a condition of high levels of uric acid in urine. It occurs in between 15 - 20% of people (mostly men) with calcium oxalate stones. Urate, the salt formed from uric acid, creates the center of a crystal (nidus), around which calcium oxalate crystals form and grow. Such stones tend to be severe and recurrent. They appear to be strongly related to a high intake of protein. (Hyperuricosuria also plays a major role in some uric acid stones.)

Low Urine Levels of Citrate (Hypocitraturia). Citrate is the main substance in the body that is responsible for removing excess calcium. It also blocks the process that turns calcium crystals into stones. Low levels of citrate in the urine (hypocitraturia) is a significant risk factor for calcium stones. In addition, hypocitraturia also increases the risk for uric acid stones. This condition most likely contributes to about a third of all kidney stones.

Many conditions can reduce citrate levels. Some causes include:

Renal tubular acidosis
Potassium or magnesium deficiency
Urinary tract infection
Kidney failure
Chronic diarrhea

Often, however, the cause of hypocitraturia-related stones is unknown.

Low Levels of Other Stone-Blocking Compounds. Several other compounds in the urine, including magnesium and pyrophosphate, also prevent the formation of calcium stones. If any of these compounds are lacking, stones may develop.

Nanobacteria Infection. Nanobacteria are tiny infectious organisms that can pass from the blood into urine. They coat themselves with mineral deposits that resemble the composition of kidney stones. Cells infected with these bacteria develop mineral deposits on the inside and outside. Researchers believe that nanobacteria may form the cores of the kidney stones in many people.

Human body tissues, certain foods, and certain alcoholic drinks contain substances called purines. Purine-containing foods include dried beans, peas, and liver. When the body breaks down purines, it produces uric acid. The presence of a certain level of uric acid in the body is normal.

The following conditions are usually seen in patients with uric acid stones:

Too much acid in the urine for a long period (the most important cause of uric acid stones)
Lower than normal amounts of urine produced.
Hyperuricosuria, a metabolic disorder that leads to high levels of uric acid in the urine

Note: Hyperuricosuria can also trigger calcium stones. Therefore, a combination of calcium and uric acid stones may be present in patients with hyperuricosuria.

A number of conditions and other factors may contribute to, or cause, uric acid stones:

Gout: Uric acid and other kidney stones develop in up to 25% of patients with primary gout, a painful form of arthritis that occurs when uric acid in the blood forms crystals in one or more joints.
Diabetes: New research has shown that people with type 2 diabetes have highly acidic urine that can lead to kidney stones, particularly uric acid stones. The findings were published in the May 2006 Journal of the American Society of Nephrology.
Insulin resistance: People with insulin resistance are at an increased risk for uric acid stones. The reason is unknown but may be related to the transport of certain salts through the kidneys. This transport changes in patients with insulin resistance.
Kidney abnormalities: Kidney problems that reduce the production of ammonia, particularly in people with diabetes or insulin resistance, may lead to uric acid stones.
Genetic factors: Genetic factors can increase a person's risk for uric acid stones.
Hypocitraturia: Hypocitraturia is a low amount of citrate in the urine.
Diet: Eating too much animal protein increases the risk of forming uric acid stones.

Other risk factors include:

Certain medications (chemotherapy drugs, diuretics, and salicylates)
Binge drinking
Not eating for long periods of time (fasting)
Lead poisoning
Blood cancers (leukemia, multiple myeloma, and lymphomas)
Some rare types of anemia (low levels of red blood cells in the blood)
Chronic diarrhea

Struvite stones are almost always caused by urinary tract infections due to bacteria that produce certain enzymes. These enzymes raise the concentration of ammonia in the urine. Ammonia makes up the crystals that form struvite stones. The stone-promoting bacteria are usually Proteus, but may also include Pseudomonas, Klebsiella, Providencia, Serratia, and staphylococci. Women are twice as likely to have struvite stones as men.

Other stones, including cystine and xanthine stones, are usually due to genetic abnormalities.

Causes of Cystine Stones. Cystine stones develop from genetic defects that cause abnormal transport of amino acids in the kidney and gastrointestinal system leading to a build-up of cystine, one of these amino acids. Researchers have identified two genes responsible for this condition: SLC3A1 and CLC7A9.

Causes of Xanthine Stones. In some cases, xanthine stones may develop in patients being treated with allopurinol for gout.

Risk Factors

Kidney stones are one of the most common disorders of the urinary tract. They are an ancient health problem. Evidence of kidney stones has been found in an Egyptian mummy estimated to be more than 7,000 years old.

An estimated 1.3 million Americans seek medical help for kidney stones each year. At this time, studies suggest kidney stones affect over 5% of Americans and that the rate has increased since the 1970s, perhaps because of increases in animal and dietary protein intake.

Men. The risk of kidney stones increases in a man's 40s and continues to rise until age 70. Caucasian men are at higher risk than other groups.

Women. The risk of kidney stones peaks in a woman's 50s. In younger women, stones are more likely to develop during the late stages of pregnancy. Pregnant women tend to have a higher calcium intake, but their kidneys do no handle the calcium as well as they did prior to pregnancy. Kidney stones are still a rare occurrence during pregnancy, however, affecting only 1 in 1,500 pregnancies.

Risk Factors in Children. Stones in the urinary tract in children are usually due to genetic factors. Most of the time, the cause is too much calcium in the urine (hypercalciuria). Deformities in the urinary tract pose a significant risk for kidney stones in children. Children with low birth weight who need to be fed intravenously are also at risk for stones.

Obesity and weight gain are both associated with an increased risk of kidney stones.

Men who weigh more than 220 lbs are 44% more likely to develop kidney stones than men who weigh less than 150 lbs.
Women who are obese are 90% more likely to develop kidney stones than women with a lower body mass index (BMI).

Higher BMIs and larger waist circumferences are both risk factors for kidney stones. Researchers think that there may be a link between fat tissue, insulin resistance, and urine composition. People with larger body sizes may excrete more calcium and uric acid, which increase the risk of kidney stone formation.

A family history of kidney stones increases one's risk for the condition. Researchers are looking into markers or other factors that might predict kidney stones in relatives, although none has yet been clearly identified. One report found that among the siblings of patients with calcium stones, sisters with higher urinary calcium levels and more acidic urine were more likely to develop stones. Brothers with high urinary calcium, low urinary potassium, and older age were more likely to have the problem. A family history of gout may also make a person vulnerable to stones.

According to a 2003 study of American ethnic groups, Caucasians have the highest incidence of kidney stones (5.9%) followed by Mexican Americans (2.6%). African-Americans have the lowest risk (1.7%).

Dietary factors, minerals in local water, or both may contribute to geographic differences that have been observed in the occurrence of kidney stones. Studies have reported the highest occurrence of kidney stones in the southern region of the United States and the lowest in the west. One study suggested that the higher risk may be due to a higher rate of high blood pressure in the southern states and certain dietary habits, particularly lower intake of magnesium and low use of calcium supplements.

Specific Foods. In general, certain foods increase the risk for stones only in people who have genetic or medical vulnerability. People whose diets are high in animal protein and low in fiber and fluids may be at higher risk for stones. A number of foods contain oxalic acid, but there is no proof that such foods make any major contribution to calcium oxalate stones in people without other risk factors. However, several studies have shown that increasing dietary calcium and restricting salt, animal protein, and foods rich in oxalate can help prevent calcium oxalate stones from returning.

Stress. One study reported that people who had a major, stressful life experience were more likely to develop stones than those who had not. Some experts speculate that this increased risk may be due to a hormone called vasopressin, which is released in response to stress. Vasopressin also increases the concentration of urine.

Sleep Position. Sleeping in the same position consistently may influence risk. A 2001 study reported that in people who had a history of kidney stones, recurrences tended to occur on the same side that people slept on. An earlier study suggested that people who had kidney stones were more apt to sleep on their stomachs. Movement during sleep did not appear to affect the risk.

Being Bedridden. Any medical or physical condition that keeps a person in bed or immobile increases blood levels of calcium from bone breakdown, thereby posing a risk for stone formation.

Gout. Patients with gout are at a high risk of uric acid stones. These patients have very acidic urine, and a 2002 study suggested that the two disorders may have a common source.

High Blood Pressure. Persons with high blood pressure are up to three times more likely to develop kidney stones. It is not entirely clear whether having high blood pressure increases the risk for a stone, whether stones lead to high blood pressure, or if there is an action linking both.

Inflammatory Bowel Disease: Crohn's disease and ulcerative colitis cause problems in absorption of substances in the intestines. These problems significantly increase the risk for kidney stones, particularly in men.

Urinary Tract Infections (UTIs): Urinary tract infections are almost always the cause of struvite stones.

Hyperparathyroidism: The parathyroid glands regulate calcium levels in the body through the parathyroid hormone. In hyperparathyroidism, one or more of these glands makes too much parathyroid hormone. Some people with hyperparathyroidism develop kidney stones. Surgery to remove the hyperactive parathyroid gland in such patients reduces the risk for stone formation, but the risk still remains high for some time after surgery.

Other Medical Conditions. Kidney disease, chronic diarrhea, certain cancers (such as leukemia and lymphoma), and sarcoidosis put people at higher risk for stones.

AIDS medications. Over 10% of persons with AIDS who take the medicine indinavir develop stones. The risk is even higher in patients with AIDS who also have hepatitis B, hepatitis C, or hemophilia, as well as those who are very thin or who take the antibiotic combination TMP-SMX. In one study of persons with AIDS who took a combination of indinavir, zidovudine, and lamivudine, 36% developed kidney stones.

Other Drugs. Kidney stones are a rare side effect of thyroid hormones and loop diuretics (drugs that increase urination). In fact, diuretics are also used to prevent calcium stones. Certain cancer chemotherapies can also cause kidney stones. Long-term use of medications, such as antacids, which change the acidic content of urine, may increase the risk for kidney stones.

Symptoms

In many cases, kidney stones do not produce symptoms. However, if a stone becomes stuck in the ureter (the thin tube between the bladder and the kidney), symptoms can be very severe. Often, they vary depending on the stone's location and its progress.

Kidney stone attacks tend to be most common late at night or in the early morning, possibly because of minimal urine output or constriction of the ureters during the early morning hours. Kidney stone attacks are least common during the late afternoon

Pain usually begins abruptly on one side and then usually continues as intense, constant pain. (In some cases it persists for a few minutes, disappears, and then returns after about 10 minutes.)
The patient cannot become comfortable and usually stands, sits, paces, or reclines in a vain search for a position that will bring relief.
If the stone is in the kidney or upper urinary tract, the pain usually starts in one flank area (to the side of the back near the waist). It typically moves to the groin as the stone passes down.
If the stone is too large to pass easily, the pain follows the muscle contractions in the wall of the ureter as they try to squeeze the stone along into the bladder.
Nausea and vomiting may occur.
Blood in the urine may be present.
As the stone passes down the ureter closer to the bladder, a person may feel the need to urinate more often or a burning sensation during urination.
If fever and chills accompany any of these symptoms, an infection may be present.

The size of the stone does not necessarily predict the severity of the pain; a very tiny crystal with sharp edges can cause intense pain while a larger round stone may not be as distressing. Struvite stones can often occur without symptoms.

Diagnosis

The doctor will perform a physical exam. This includes pressing against abdominal areas for tender locations that might indicate the presence of the stone.

The patient's age is a significant factor. Kidney stones that occur in children and young patients are more apt to result from inherited problems that cause cystine, xanthine, or, in some cases, calcium oxalate stones. In adult patients, calcium stones are most common.

A medical history may help predict which crystal has formed the stone. The doctor will need to know the following:

Any previous kidney stone attacks
Histories of cancer, sarcoidosis, or small bowel disease
Any medications being taken, including non-prescription substances, particularly high doses of vitamins D or C and calcium-containing antacids

Many conditions can cause symptoms similar to kidney stones. Usually the diagnosis is easily made because of the specific nature of the symptoms, but it is not always clear. Urinary tract infections can cause similar, but usually less intense, pain. In fact, infection may be present with a kidney stone. Other causes of pain that may mimic kidney stones include:

Gallstones
Diverticulitis (infection or irritation of abnormal pockets in the intestines)
Intestinal blockage
Blood clots
Irritable bowel syndrome
Appendicitis
Stomach ulcers
Hiatal hernia (when the upper part of the stomach bulges into the chest, through an opening in the diaphragm)
Pancreatitis (inflammation of the pancreas)
Hepatitis
Pelvic inflammatory disease
Inflammatory bowel disease (Crohn's and colitis)
Heart attack

Various imaging techniques are helpful in determining the presence of kidney stones. The best approach uses spiral (or helical) computed tomography scans. If it is not available, the patient will need ultrasound or standard x-rays. If no stones show up, but the patient has severe pain that suggests the presence of kidney stones, the next step is an intravenous pyelogram.

X-Rays. A standard x-ray of the kidneys, ureters, and bladder may be a good first step for identifying many stones, since many are visible on x-rays. Calcium stones can be identified on x-rays by their white color. Cystine crystals can also show up on x-rays.

Spiral (or Helical) Computed Tomography. A type of computed tomography (CT) scan, called a spiral or helical CT scan, is currently the best method for diagnosing stones in either the kidneys or the ureters. This test is fast, does not require instruments or foreign chemicals to enter the body, and provides detailed accurate images of even very small stones. If stones are not present, a spiral CT scan can often identify other causes of pain in the kidney area. It is better than x-rays, ultrasound, and intravenous pyelogram -- the previous standard test for detecting kidney stones. Experts hope spiral CT will eventually be able to identify the chemicals present in a stone.

Ultrasound. Ultrasound can detect clear uric acid stones and obstruction in the urinary tract. It is not useful for finding very small stones, but some research indicates that it may be a useful first diagnostic step in the emergency room to help predict the likelihood of a stone, including suspected stones in children.

Intravenous Pyelogram. With intravenous pyelogram (IVP), the doctor injects a special dye into the patient. A technician will then take x-rays as the dye enters the kidneys and travels down the urinary tract. IVP is invasive but, until recently, was the most cost-effective method for detecting stones. Where it is available, spiral CT is now preferred, since it gives a faster diagnosis, is more accurate, is safer, and is similar in cost.

In any case, IVP should not be used on patients with kidney failure. There is also a risk for an allergic reaction to standard dyes, although newer less allergenic ones are becoming available.

In the procedure intravenous pyelogram (IVP), the patient is injected with dye. X-rays are taken as the dye travels through the urinary tract. This procedure is done to confirm the presence of kidney stones, although some stones may be too small to see.

Magnetic Resonance Imaging. Magnetic resonance imaging (MRI) techniques are showing promise for diagnosing urinary tract obstruction but do not yet accurately reveal small stones, or ones that do not cause a blockage. Because no radiation is involved with MRI, however, it may prove to be a good option for pregnant women.

Urine samples are required to evaluate features of the urine, including its acidity and the presence of:

Red or white blood cells
Infection
Crystals
High or low levels of chemicals that inhibit or promote stone formation

Clean-Catch Urine Sample for Culturing. After determining that a kidney stone is present, the health care provider usually gives the patient a collection kit, including filters, to try to catch the stone or gravel as it passes out. The urine may also be tested (cultured) for the presence of infection-causing organisms. A clean-catch urine sample is almost always required for culturing. To provide a clean catch, do the following:

First, wash your hands thoroughly, then wash the penis or vulva and surrounding area four times with downward strokes, using a new soapy sponge each time.
Begin urinating into the toilet and stop after a few drops.
Position the container to catch the middle portion of the urine stream. Ideally, this urine will contain only the bacteria and other evidence of the stone.
Urinate the remainder into the toilet.
Tighten the cap on the container securely, being careful not to touch the inside of the rim.

Click the icon to see an image of a calcium urine test.

Twenty-Four Hour Urine Collection. A 24-hour urine collection may be needed to measure urine volume and levels of acidity, calcium, sodium, uric acid, oxalate, citrate, and creatinine.

You should not change any of your usual eating or drinking patterns when performing this test.
Discard the first urination on the day of the test.
Afterward all urine passed over the next 24 hours is collected, including the first urination on the morning of day two.
A second 24-hour urine collection may be needed to determine if treatment is working or if the first analysis was not conclusive and the doctor suspects a less common stone, such as a cystine or xanthine stone.

Click the icon to see an image of a uric acid urine test.

Urine tests that are used to determine the specific chemical and biological factors causing the stone should be performed about 6 weeks after the attack, since the attack itself may change the levels of such substances, including calcium, phosphate, and citrate. It should be noted that calcium levels in the urine may be abnormal even in many people without stones. In addition, high urinary concentrations of calcium may pose a greater or lesser risk depending on age. (In one 2001 study, middle-aged adults with high urinary calcium concentrations had a much greater risk than older adults with high levels.)

The kidney stones obtained from the urine sample are examined under a microscope. The crystal formations are often specific enough so that the doctor is able to identify the substance causing the stone.

Calcium oxalate crystals are eight-sided, while calcium phosphate crystals tend to have irregular shapes.
Uric acid stones are sometimes described as pear-shaped or diamond-shaped.
Some struvite stones have very specific shapes commonly described as "coffin lids." Struvite crystals may also occur in a formation known as a staghorn, which can be large and damaging to the kidney.

Testing whether urine is acidic or alkaline helps to identify the specific type of stone. The levels of acidity or alkalinity in any solution, including urine, are indicated by the pH scale:

A pH value of 7.0 is neutral.
A solution with a low pH (below 7.0) is acidic. (A low pH favors uric acid and cystine stones.)
A solution with a high pH is alkaline. (A high pH favors calcium phosphate and struvite stones.)

A dipstick test for blood in the urine (called hematuria) is typically performed when patients appear in the emergency room with flank pain (the primary symptom of kidney stones). About a third of kidney stone patients, however, do not show blood in the urine, so other tests may be needed.

Blood Tests for Stone Factors. Blood and urine tests help determine what substances form the crystals. This allows the doctor to determine the appropriate treatment and preventive measures.

Blood tests may help determine blood levels of urea nitrogen, creatinine, calcium, phosphate, and uric acid for patients with known or suspected calcium oxalate stones. Doctors will usually schedule these tests about 6 weeks after the attack, in order to measure these substances when the stone has been passed, and the patient has been stabilized. This is particularly true in patients with recurrent stones.

Parathyroid Tests. Tests to detect parathyroid hormone levels are given if the doctor suspects hyperparathyroidism, based on other signs and symptoms.

Tests for Infection. A test result that shows a high white blood cell count might indicate infection. Such results, however, could be misleading, since the number of white blood cells could also increase in response to the extreme physical stress of a kidney stone attack.

Tests for Metabolic Problems. About half of children with stones have an identifiable metabolic disorder, which increases their risk of stone recurrence five-fold. Experts argue whether tests for metabolic disorders are routinely needed once the stone composition has been determined. Studies suggest the following:

People with recurrent calcium stones have a wide range of irregular blood or urine test results, indicating a variety of possible metabolic disorders. For example, calcium stones in middle-aged women may be due to parathyroid abnormalities.
Calcium phosphate stones most likely result from renal tubular acidosis.
People with non-calcium stones generally have identifiable metabolic disorders.
Determining the stone composition may be sufficient for treatment, and may help avoid unnecessary metabolic tests.

Treatment

When tests show there is a kidney stone, the next step is to determine treatment. The patient should be admitted to the emergency room if they have severe vomiting, fever, or symptoms of infection.

Strong opioid painkillers, such as meperidine (Demerol), are often required for a severe kidney stone attack. However, doctors will usually not give such drugs until they confirm the presence of a kidney stone on an x-ray. In some cases, powerful nonsteroidal anti-inflammatory drugs (NSAIDs) may work just as well as opioids, and they have fewer side effects. However, they do take longer to work.

In about 85% of patients, the kidney stones are small enough that they pass through normal urination, usually within 2 to 3 days. In some cases, a stone may take weeks to months to pass, although pain usually goes away before that.

The patient should drink plenty of water (two to three quarts a day) to help move the stone along, and take painkillers as needed. The doctor usually provides a collection kit with a filter and asks the patient to save any passed stones for testing.

If the stone has not passed in 2 - 3 days, the patient will need additional treatments. In some severe cases, hospitalization may be necessary.

Specific procedures vary depending on the size of the stone or complexity of the situation. Noninvasive procedures are proving to be very beneficial in eliminating stones, and have largely replaced invasive surgeries.

For small stones that are lodged in the lower part of the ureter, ureteroscopy or shock wave lithotripsy are the procedures of choice.
For larger stones, ureteroscopy, percutaneous nephrolithotomy, and shock wave lithotripsy are all potentially useful. The choice of any of these procedures depends on a number of factors, including location of the stone and the presence of any problems that caused the stone in the first place.
In some complicated cases, standard open surgical procedures (called nephrolithotomy) may be required.

See "Other Treatments" section for more information on kidney stone surgery.


Stone Type	Diet and Lifestyle	Medications	Procedures
Calcium Oxalate	Plenty of fluids. (Choose water, lemon juice. Avoid grapefruit, apple, and cranberry juice.) Limit the amount of protein and salt in the diet. Increase fiber. Limit the amount of fats in the diet, particularly in people who have short bowel syndrome. Balance normal calcium intake with potassium- and phosphate-rich foods. Limit the amount of calcium in the diet (only in people who have genetic abnormalities that cause high intestinal absorption of calcium). Limit the amount of foods high in oxalates (only in patients with rare intestinal conditions that cause hyperoxaluria).	Diuretics ("water pills"), Citrate salts, phosphates, cholestyramine.	Lithotripsy, uteroscopy, percutaneous nephrolithotomy, open surgery.
Uric Acid	Plenty of fluids. (Choose water, blackcurrant juice. Avoid cranberry juice.) Increase calcium intake (be sure well-balanced with potassium and phosphates). Reduce protein and other foods with high-purine content.	Potassium citrate, sodium bicarbonate, allopurinol.	Lithotripsy, uteroscopy, percutaneous nephrolithotomy, open surgery.
Struvite stones	Plenty of fluids (water, cranberry juice). Reduce proteins.	Antibiotics to eliminate any infection. Acetohydroxamic acid (AHA) may be helpful in combination with antibiotics. In some cases, organic acids given through urinary tract.	May respond poorly to most lithotripsy procedures and require open surgery. Newer procedures may be helpful.
Cystine stones	Very high fluid intake (four quarts a day). Limit the amount of protein in the diet.	Alkalizing agents (such as bicarbonate). Sometimes d-penicillamine, tiopronine, or captopril useful for lowering cystine levels.	May respond poorly to most lithotripsy procedures and require open surgery. Newer procedures may be helpful.

Medications

Diuretics. Diuretics are medicines commonly used to treat high blood pressure and other disorders. They remove fluid and sodium from the body. Low doses of a class of diuretics known as thiazides are sometimes used to reduce the amount of calcium released by the kidneys into the urine. Thiazides include:

Hydrochlorothiazide (Esidrix, HydroDiuril)
Chlorothiazide (Diuril)
Trichlormethiazide (Metahydrin, Naqua)
Chlorthalidone (Hygroton)

However, thiazides also cause potassium loss, which reduces citrate levels and can increase the risk for stones. Patients taking thiazide pills should also take potassium citrate, to prevent citrate loss. Amiloride (Midamor) is a potassium-sparing diuretic, which may be used if a thiazide does not work.

Citrates. Citrate salts are often given to people with calcium oxalate or uric acid stones:

Potassium magnesium citrate is available over the counter. It is proving to be very beneficial in preventing kidney stones. In one study, potassium magnesium citrate reduced the risk for kidney stone recurrence by 85%.
Potassium citrate (K-Lyte, Polycitra-K, Urocit-K) is given as the only treatment to people with normal urine calcium levels. Between 70 - 75% of patients with recurrent stones have ongoing remission (no stone recurrence) with potassium citrate treatment. However, some people cannot tolerate potassium citrate because of side effects (stomach problems).
Magnesium citrate (Citroma, Citro-Nesia) may help people who develop calcium stones from impaired intestinal absorption due to short bowel disease.

None of these products should be used by people with struvite stones, urinary tract infections, bleeding disorders, or kidney damage. Patients who take citrate supplements containing potassium should not take any other medications that either contain this mineral or prevent its loss (such as so-called potassium-sparing diuretics). People with peptic ulcers should avoid citrate supplements, or discuss using non-tablet forms with their doctor.

Phosphates. Phosphates help reduce the breakdown of bone that releases calcium into the bloodstream. They are also involved in the kidney's reabsorption of calcium from the urine.

Phosphate compounds:

Neutral (nonacidic) sodium or potassium phosphate (K-Phos, Neutral, Neutra-Phos) is usually taken four times a day after meals to prevent kidney stones unless otherwise directed by the doctor. Diarrhea is a possible side effect.
Cellulose phosphate (Calcibind) is recommended only for severe hypercalciuria that is associated with recurrent calcium stones and is caused by excessive absorption of calcium from the intestines. However, this drug may increase oxalate levels and decrease magnesium levels, which can lead to different stones. Taking magnesium supplements and reducing dietary oxalates, calcium, and ascorbic acid may help offset these risks. Cellulose phosphate may also cause bloating.

Avoid acidic forms of phosphate, since they increase the risks for both hypocitraturia and hypercalciuria.

Cholestyramine (Questran, Questran Light) is a drug used to reduce cholesterol levels. However, it also binds with oxalate in the intestine, so it is also used to reduce high oxalate levels in urine (hyperoxaluria). The drug usually comes in a powder that is dissolved in liquid.

Bloating and constipation are common side effects of this drug. Cholestyramine also interferes with other medications, including digoxin (Lanoxin) and warfarin, and may contribute to calcium loss and osteoporosis. In order to prevent such interactions, take other drugs 1 hour before, or 4 - 6 hours after, taking cholestyramine.

Long-term use of cholestyramine may cause deficiencies of vitamins A, D, E, and K. Vitamin supplements may be necessary.

Sodium Bicarbonate. Patients whose persistently acidic urine causes uric acid stones may take sodium bicarbonate to reduce urine acidity. Patients taking sodium bicarbonate must test their urine regularly with pH paper, which turns different colors depending on whether the urine is acidic or alkaline. Too much sodium bicarbonate can cause the urine to become too alkaline. This increases the risk for calcium phosphate stones. Patients who need to reduce the amount of sodium they take in (as a result of other medical conditions) should not use sodium bicarbonate.

Potassium Citrate. Potassium citrate, which restores citrate to the urine, is useful for patients with high levels of uric acid in the urine.

Allopurinol. Allopurinol (Lupurin, Zyloprim) is very effective in reducing high levels of uric acid, and may be helpful for patients with uric acid stones. Allopurinol will not prevent calcium stones from forming. There is also a slight risk for the formation of xanthine stones with this drug. Side effects include diarrhea, headache, and fever. More severe complications include blood disorders that may produce fatigue, bleeding, or bruising. The drug may also increase the risk for cataracts.

About 2% of patients experience an allergic reaction to allopurinol that causes a rash. In rare cases, the rash can become severe and widespread enough to be life threatening. Allergic individuals who have experienced only a mild rash to sodium bicarbonate may be able to build up their tolerance for allopurinol by undergoing a desensitization process. In this process, patients start with small doses of allopurinol and gradually increase them, if no reaction develops.

Allopurinol reduces uric acid levels rapidly, so it may trigger an attack of gout in vulnerable people. To prevent this problem, patients taking allopurinol should also take a nonsteroidal anti-inflammatory drug (NSAID) for 2 or 3 months. Aspirin should not be taken, since it increases uric acid levels. Patients should discuss the appropriate NSAID choice with their doctor.

Before patients can receive any medical treatment for struvite stones, they must have surgery to completely remove the stones.

Antibiotics for Eliminating Infection. Persons with struvite stones receive ongoing treatment with antibiotics to keep the urine free of the bacteria that cause urinary tract infections. Careful follow-up and urine testing is extremely important. A high-pH urine indicates low acidity and an increased risk of infection.

Acetohydroxamic Acid (AHA). Acetohydroxamic acid (AHA or Lithostat) is beneficial when used with long-term antibiotics. AHA blocks enzymes that bacteria release, and has been effective in preventing stones even when bacteria are present. Side effects, however, can be severe. The drug reduces iron levels in the body, so anemia is a common problem. Patients may need to take iron supplements. Other side effects include nausea, vomiting, depression, anxiety, rash, persistent headache, and, rarely, small blood clots in the legs.

Experts recommend this drug only for patients with healthy kidneys who have chronic diseases caused by specific struvite-causing organisms.

Patients taking this medicine should avoid alcohol. Pregnant women should not take acetohydroxamic acid.

Organic Acids. Medical treatments to dissolve stones may be useful in patients who do not respond to other medications, or in combination with surgeries. Acidic urine dissolves struvite stones, so the doctor may wash the urinary tract with a solution of organic acids (such as Renacidin). Candidates for such washes must have sterile urine (no bacteria or other organisms in the urine) and healthy kidney function. In surgical patients, the wash is performed 4 or 5 days after the operation. The wash starts with saline (salt solution) for 1 - 2 days and, if there are no problems, the organic acid solution follows for another 1 or 2 days, until all stones dissolve. Regular urine tests are necessary to ensure that the bacteria do not return.

Aluminum Hydroxide Gel. An aluminum hydroxide anti-acid gel may reduce phosphate levels that are important in struvite stone formation, but it has a long-term risk of causing aluminum toxicity. Long-term reduction of phosphorus can also increase the risk for calcium oxalate stones. Experts recommend limiting phosphorus through a low-protein diet, rather than through the use of this gel.

The first-line treatment for cystine stones is increasing the alkalization of urine so the stones can dissolve. If alkalization fails, drug treatments may include d-penicillamine, alpha-mercaptopropionylglycine (tiopronine), or captopril. These medications lower cystine concentration.

Patients with cystine stones must drink plenty of fluids, much more than patients with other stones. The patients should drink at least four quarts of water over a 24-hour period.

Other Treatments

Surgery is usually needed if the stone is too large to pass on its own, if there are signs that the stone is growing, or if the stone is blocking the urine flow and causing a urinary tract infection or kidney damage.

Until recently, the procedure to remove a stone was a very painful, major surgery, requiring 4-6 weeks of recovery. Today, treatments for stones are much less invasive. Major surgery is performed in less than 2% of patients.

Stone removal procedures:

Extracorporeal shock wave lithotripsy (ESWL) is used for small stones (less than one centimeter, or slightly less than half an inch) that occur in the upper part of the ureter and do not pass on their own. One study indicated lithotripsy might even be safe and effective for patients whose stones are associated with malformed kidneys, although such patients are at higher risk for stone recurrence and should be carefully monitored.
Percutaneous nephrolithotomy (PNL). PNL can be used for very large stones in the upper urinary tract, when ESWL fails, for kidney transplant patients, or when the kidneys or surrounding areas are malformed. PNL is the preferred procedure for drug-resistant cystine stones, which are usually also resistant to shock wave therapy.
Ureteroscopy. For stones in the lower tract, ureteroscopy is generally the best procedure, although lithotripsy is also usually feasible and patients ordinarily prefer it.
Standard open surgery (nephrolithotomy) may be required if any of these procedures fail or are not appropriate, or in special cases, such as when the patient is very obese.

Most procedures are more effective for calcium and uric acid stones and less effective for struvite and cystine stones, although new techniques may be improving their effects on all stones.

Extracorporeal shock wave lithotripsy (ESWL) is a technique that uses sound waves (ultrasound) to break up simple stones in the kidney or upper urinary tract. ("Extracorporeal" means "outside the body," and "lithotripsy" means stone-breaking.) ESWL is not used for cystine stones. The procedure generally does not work for stones larger than three centimeters in diameter (which is slightly over an inch). There are several variations of ESWL. The following is a typical procedure:

Most ESWL procedures use some anesthesia, although they are often done on an outpatient basis.
The patient is positioned in a water bath. (In some procedures the patient lies on a soft cushion.)
The procedure uses ultrasound to generate shock waves that travel through the skin and body tissues until they hit the dense stones. (The doctor pinpoints the stone during treatment by using x-rays or ultrasound.)
The shock waves crush the stones into tiny sand-like pieces that usually pass easily through the urinary tract.
The shattered stone fragments may cause discomfort as they pass through the urinary tract. In such cases, the doctor may insert a small tube called a stent through the bladder into the ureter to help the fragments pass. This practice, however, has not proved to speed up passage of the stones in most cases and is not used routinely.

Extracorporeal shock wave lithotripsy (ESWL) is a procedure used to shatter simple stones in the kidney or upper urinary tract. Ultrasonic waves are passed through the body until they strike the dense stones. Pulses of sonic waves pulverize the stones, which are then more easily passed through the ureter and out of the body in the urine.

Success rates of ESWL range from 50 - 90%, depending on the location of the stone and the surgeon's technique and level of experience. Recovery time is short, and most people can resume normal activities in a few days.

Complications. Complications may include the following:

The most common complication is blood in the urine, which lasts for a few days after treatment. To reduce the chances of bleeding, doctors usually tell patients to avoid taking aspirin and other NSAIDs, which can promote bleeding, for 7 - 10 days before the treatment.
Bruising and minor discomfort due to the shock waves are common in the back or abdomen.
Sometimes the stone does not completely break up with one treatment, and additional treatments may be required. Inability to pass stone fragments may also be a particular problem in patients who have cysts or other kidney problems.
Higher risk for diabetes later. A 2006 study published in the journal Urology found that 17% of patients who received shock-wave lithotripsy developed diabetes later in life. The diabetes risk was related to the number and intensity of shocks.
Higher risk for hypertension (high blood pressure). The same study that linked ESWL to diabetes also showed that people who received shock-wave lithotripsy treatment were 47% more likely to develop high blood pressure than those who had their stones treated without surgery.

ESWL appears to be safe for children, although a 2001 study reported temporary damage in the kidney tubules after treatment. It is unclear if this complication has any long-term consequences. Experts recommend using the least amount of shocks and impact possible in young people. If more than one treatment is needed, there should be a waiting period of at least 15 days between treatments.

Percutaneous nephrolithotomy may be used when ESWL is not available or effective (such as if the stone is very large, in an inaccessible location, or is a cystine stone). It is also preferred over ESWL for stones that have remained in the ureter for more than 4 weeks.

It is more effective than ESWL for patients with severe obesity, and appears to be safe for the very elderly and the very young. Success rates are nearly 98% for kidney stones and 88% for ureteral stones. They may vary by the technique used and the specific patients. For example, success rates are slightly lower in children, although the procedure can be done safely in young patients. Long-term effects are unknown.

A typical procedure is as follows:

The surgeon makes a tiny incision in the back and creates a tunnel directly into the kidney.
The surgeon then inserts an instrument called a nephroscope through the tunnel.
The stone is located and removed. If it is large, it is destroyed using ultrasound, lasers, or other devices. The surgeon then removes the fragments. An advantage of percutaneous nephrolithotomy over ESWL is that the surgeon is able to remove the stone fragments directly, instead of relying on their natural passage from the kidney.
Generally, patients stay in the hospital for 5 or 6 days and may need a small device called a nephrostomy tube left in the kidney during the healing process.

Devices Used to Destroy Stones. For large stones, some type of energy-delivering device may be needed to break the stone into small pieces. They are referred to as intracorporeal lithotripsy devices (meaning stone breakers within the body). The device may be one of the following:

Ultrasound is currently the preferred method. It results in a stone-free rate of 94%. A rigid nephroscope delivers the ultrasound waves.
Pneumatic (compressed air) lithotripsy uses a probe that comes in direct contract with a stone. Compressed air causes a piston to collide rapidly with the probe, and the result is a "jackhammer" action against the stone, causing the stone to break up. This method, however, can send stone fragments into other parts of the urinary tract.
A more recent device uses a combination pneumatic probe and ultrasound, with stone-free rates of 80 - 89%. It may prove to be superior to ultrasound alone and be effective against stones of all types.
The holmium laser literally melts the stones and destroys up to 100% of stones of any composition. It uses a flexible nephroscope and has an excellent safety record. It should be used sparingly, however, with particular caution against large uric acid stones until more is understood about its effect. Another device, the erbium: YAG laser, although showing promise in lithotripsy, is not currently practical.

Complications. Complication rates are about 3%. Major complications occur in about 1% of cases. These complications may include scarring of the tissue, but studies indicate that it does not impair kidney function, even if the patient requires repeat surgery. There is also a risk for blood loss during and after the procedure, which, in some cases, can be significant.

Because the procedure requires large volumes of fluid, fluid overload is a potential problem, particularly in children or patients with heart disease.

In some cases, infection may result. Other complications may include a collapsed lung and injuries to areas outside the kidney (but within the operative area), such as the abdomen or chest.

Ureteroscopy may be used for stones in the middle and lower ureter. With the arrival of smaller instruments, this procedure can be done successfully in children as well. The procedure involves the following:

The patient receives a general anesthetic, though no incision is required for the procedure.
The surgeon passes a small fiberoptic instrument called a ureteroscope through the urethra and bladder into the ureter.
The surgeon locates the stone or stones.
The surgeon can remove smaller stones by grasping them with small forceps. A laser or pneumatic device breaks up large stones.
The surgeon may decide to leave a small tube, or stent, in the ureter for a few days after treatment, to help the lining of the ureter heal.

Complication rates range from 10 - 20%, with major problems occurring in up to 6% of patients. In some cases, large stones are not broken up into small enough pieces. This can result in blockage of the urinary tract and possible kidney damage.

Imaging tests, such as ultrasound or spiral CT, are useful within 3 months to check for residual stones, and a second procedure may be required. The risk of complications is highest when the procedure is performed by less experienced surgeons, or if stones are found in the kidney. The risk for perforation of the ureter increases the longer the procedure takes.

Open surgery involves incisions through the patient's flank and into the kidney. The surgeon will cool the kidneys using ice. X-rays during the procedure help locate the stone. At the beginning of the surgery, the surgeon will isolate the arteries supplying the kidneys, ensuring they are not harmed during the surgery. The surgeon will then locate and remove the stone. The surgeon will also correct any blockage in the affected area. The surgery, called nephrolithotomy, is very invasive and is restricted to the following:

Patients with very large or complex stones that cannot be removed using less invasive measures
Very obese patients

Some centers report success with extracorporeal shock wave lithotripsy, however, in patients who would normally be nephrolithotomy candidates. Therefore, even these patients should discuss other options with their surgeon.

The procedure is not appropriate for patients with:

Bleeding or clotting disorders
Untreated widespread infection
Severe and chronic kidney insufficiency (unless removing the stone will improve kidney function)

Complications

Between 70 - 90% of crystals remain tiny enough so that they can travel through the urinary tract and leave the body in the urine without being noticed. When they do cause symptoms, however, kidney stones have been described as one of the most painful disorders to afflict humans. The pain they cause is sometimes called renal colic. ("Renal" means "kidney.")

Obstruction and Infection. Although kidney stones often lead to obstruction (blockage) of the urinary tract, the blockage is usually temporary and causes no lasting damage. In some cases, however, particularly if the obstruction progresses with no symptoms, infection may occur, which can be serious and need immediate attention.

Kidney Failure. It is very rare for kidney stones to cause kidney failure, although some people have risk factors that make them more vulnerable to this serious complication. Risk factors include the following:

Very frequent recurrences (such as in people with cystine stones or other inherited forms of kidney stone disorders)
Accompanying episodes of urinary tract infections with obstruction, a particular risk with struvite stones
A history of multiple urologic procedures for kidney stones
Greater size of the kidney stone gravel

Without preventive treatment, calcium stones recur in 10% of patients within a year of the first attack, and in half of patients within 5 - 7 years. Individual risk for recurrence, however, varies depending on the stone and the underlying condition. For example, a 15-year-old with inherited cystine stones has a very high risk for recurrence, while a middle-aged man with a first calcium oxalate stone has a good chance of never passing another.

Prevention

All individuals who have experienced kidney stones should take some specific preventive measures to prevent recurrence. The following are some general observations:

The most important dietary recommendations for reducing the risk for calcium stones are increasing fluid intake, restricting sodium, and reducing protein intake.
A lower risk for calcium stones is also associated with higher potassium intake.
A high calcium diet does not appear to increase the risk for kidney stones as long as it also contains plenty of fluids and dietary potassium and phosphate. (Increasing calcium alone may pose a modest risk for stones.)
Patients should try to correct any dietary habits that cause acidic or alkaline imbalances in the urine, which promote stone formation.

Because different kidney stone types may require specific dietary changes, patients should work with their doctors to develop an individualized plan. It is important to note that nutritional considerations are very important in preventing recurrence, and patients should be vigilant in complying with the proper diet.

Good voiding habits, particularly frequent urination, are important. Therefore, of all the preventive recommendations, drinking enough fluids is the most important guideline for people with any type of kidney stones.

In general, patients with calcium or uric acid stones should drink at least 10 full glasses of fluid each day (at least half should be water). This includes one with each meal and drinking fluids at night, even if it means getting up from sleep. Fluid intake should produce at least two and a half quarts of urine each day.
To prevent cystine stones, patients should drink even more water -- over a gallon, or 16 8-ounce cups, every day. Patients should drink this amount at regular intervals throughout the night and day.

In all cases, patients need more fluid after exertion and during times of stress. If they drink enough, the urine should be pale and almost watery, not dark and yellow.

Water. Although water is best, it may vary depending on its source. Variations in water itself may have different impacts. One study reported that drinking hard tap water increased urinary calcium concentration by 50% compared to soft bottled water. On the other hand, mineral water containing both calcium and magnesium may reduce several risk factors for both calcium and uric acid stone formation.

Juices and Specific Effects. Other beverages have various positive or negative effects, depending on the type of stone:

Lemon Juice: Drinking one-half cup of pure lemon juice (enough to make eight glasses of lemonade) every day raises citrate levels in the urine, which might protect against calcium stones. (While orange juice also increases citrate levels, it does not lower calcium and it raises oxalate levels. Therefore, it is not recommended.)
Cranberry and Apple Juice: Apple and cranberry juice contain oxalates, and both have been associated with a higher risk for calcium oxalate stones. Cranberry juice has properties that may increase the risk for both calcium oxalate and uric acid stones. On the other hand, cranberry juice helps prevent urinary tract infections and so may be helpful for reducing the risk for struvite and brushite stones. (These stones are far less common, however.)
Black Currant Juice: In one study, black currant juice reduced urine acidity and was associated with protection against uric acid stones.
Grapefruit Juice: A number of studies have found a risk for stones from drinking grapefruit juice. In one study, just one 8-ounce cup of grapefruit juice per day increased the risk for forming stones by 44%.

Other Beverages and Their Effects on Stone Formation.

Soft Drinks. Patients with stones should avoid cola drinks, since they can severely reduce citrate levels in the urine. Many soft drinks contain phosphoric acid, which increases the risk for stones. Some research shows that drinking one quart (less than three 12-ounce cans) of soda per week may increase a person's risk of developing stones by 15%.
Alcohol. Wine may be protective against kidney stones. A study conducted in Finland, suggests that the risk of developing stones also decreases with beer consumption. However, it is important to remember that beer is high in oxalates. Beer and other alcoholic beverages also contain purines, which may increase the specific risk for the less common uric acid stones in susceptible people. Binge drinking, in any case, increases uric acid and the risk for stones.
Coffee and Tea. Some research reported a lower risk for stones in people who drink tea and both regular and decaffeinated coffee.

A long-term 2002 study followed men with calcium oxalate stones and high levels of urinary calcium. The study found that a low-sodium, low-protein diet, containing normal levels of calcium, dramatically reduced the recurrence of stones compared to a diet that was simply low in calcium.

Salt Restriction. Because salt intake increases the amount of calcium in urine, patients with calcium stones should limit their sodium intake. Sodium may also increase levels of urate, the crystalline substance that can trigger formation of recurrent calcium oxalate stones. Although the relative contribution of limiting sodium intake has not been confirmed, some researchers believe that restricting sodium along with increasing fluid intake is the most important dietary measure for preventing stones.

Protein Restriction. Protein increases uric acid, calcium, and oxalate levels in the urine, and reduces citrate levels. Diets high in protein, particularly meat protein, have been consistently connected with kidney stones. (Meat protein has a higher sulfur content and produces more acid than vegetable protein.) A 2002 study of those following a high-protein, low-carbohydrate diet (such as the Atkins diet, for example), found dramatically increased levels of urinary uric acid and calcium after just several weeks. These effects put patients at higher risk for not just kidney stones, but possibly osteoporosis as well. According to Swiss studies, about a third of people at risk for calcium stones may have a sensitivity to meat proteins that causes mild hyperoxaluria.

Whether restricting meat protein alone has any protective value without restricting sodium as well is unknown. Most studies to date have found no difference in stone development between people with low and normal meat protein diets over four years. A 2000 study reported that only dramatic reductions in meat protein had any preventive effect against stone recurrence.

Although the precise role of dietary protein in kidney stones needs further clarification, it is reasonable for everyone to consume meat protein in moderation. People with struvite stones, who need to reduce phosphates in their diets, should also cut down on proteins.

Calcium from Foods. Dietary calcium recommendations for kidney stone prevention need to be determined on an individual basis. A doctor will suggest calcium guidelines based on a patient's age, gender, body size, and type of stone. Most studies indicate that dietary calcium (found in milk, yogurt, and cheese) protects against many types of calcium oxalate stones. Large studies of both men and women found that those with the highest intake of calcium from foods had a much lower risk for stones than those who had little calcium in their diets. A diet containing a normal amount of calcium, but reduced amounts of animal protein and salt, may protect against stones better than a low-calcium regimen. However, calcium metabolism changes as people age. Some studies suggest that a high calcium intake protects against kidney stones in men younger than age 60, but not in older men.

Dietary calcium may actually bind the oxalate in foods, preventing it from being absorbed into the blood and excreted into the urine. In a normal healthy diet, dairy products supply almost 80% of the daily calcium requirement. For people who have calcium stones associated with resorption (the breakdown of bone that releases calcium into the bloodstream), limiting calcium intake could cause further bone loss.

Calcium Supplements. Evidence on calcium supplements is mixed, although in general many studies suggest that they reduce oxalate levels and so help prevent calcium oxalate stones. One study suggested that taking 500 mg of calcium supplements a day regularly may "reprogram" the intestines to absorb less calcium and may therefore be protective. Experts generally agree that calcium supplementation within dosage recommendations (about 1,200 mg per day) remains safe. In one study, however, women who took calcium supplements had a 20% higher risk for stones. Research indicates that dosages of calcium above 2,000 mg per day are clearly associated with the formation of stones. Some experts speculate that this higher risk may occur because supplements are often taken in the morning, either without food or with breakfast, which is typically low in oxalates. Taking supplements with later meals may not produce the same risk.

Calcium Restriction in Certain Cases. Some patients, such as those whose stones are caused by genetic defects in which the intestine absorbs too much calcium, may need to limit calcium intake. More studies are needed to define this group precisely.

Fiber may be beneficial for people with kidney stones. In addition, some fiber-rich foods may contain compounds that help protect against kidney stones. A wide variety of high-fiber plant foods contain a compound called phytate (also called inositol hexaphosphate, InsP6, or IP6), which appears to help prevent crystallization of calcium salts, both oxalate and phosphate. Phytate is found in legumes and wheat and rice bran. (Soybeans are also rich in phytate but they are also very high in oxalates, so the overall effects of soy on kidney stones are not clear.)

A high intake of purines can increase the amount of uric acid in the urine. Those at risk for uric acid stones should reduce their intake of foods and beverages that contain purines. These include beer and other alcoholic beverages, anchovies, sardines, yeast, organ meats (such as liver and kidneys), legumes (including dried beans, peas, and soybeans), mushrooms, spinach, asparagus, cauliflower, and poultry.

Most people with calcium oxalate stones should not avoid oxalate-rich foods unless the doctor specifically recommends a restrictive diet. Oxalate binds with calcium in the intestine, which may actually reduce calcium absorption. Some studies, in fact, indicate that eating foods containing oxalates and calcium together may reduce the risk of stones. Most of the foods that contain oxalates are very important for good health. Limiting oxalates may be particularly harmful in people with bowel disorders marked by malabsorption.

Foods high in oxalic acid include beets, soy, beet tops, black tea, chenopodium, chocolate, cocoa, dried figs, ground pepper, lamb, lime peel, nuts, parsley, poppy seeds, purslane, rhubarb, sorrel, spinach, and Swiss chard.
Foods containing moderate amounts of oxalates include beans (green and wax), blackberries, blueberries, carrots, celery, coffee (roasted), concord grapes, currants, dandelion greens, endive, gooseberries, lemon peel, okra, green onions, oranges, green peppers, black raspberries, strawberries, and sweet potatoes.

Certain fats may play a beneficial or harmful role in specific cases of kidney stones.

Restricted Fats in Patients with Stones Associated with Bowel Disease. Patients who have stones associated with short-bowel syndrome should eat foods with lower amounts of fats and oxalates. If patients with short-bowel syndrome eat too much fat, calcium may bind to unabsorbed fat instead of to oxalates. This increased oxalate levels, resulting in increased risk of stone formation.

Fish Oil. Omega-3 fatty acids, found in oily fish like mackerel, salmon, and albacore tuna, have many health benefits, but the most current evidence suggests they do not help prevent kidney stones. A 2005 study of over 200,000 adults found that increased omega-3 fatty acid intake did not reduce kidney stone risk.

Vitamin B6. Vitamin B6, or pyridoxine, is used to treat people with primary hyperoxaluria, a severe inherited disorder. Patients should not try to treat themselves with vitamin B6. Very high doses (500 to 2,000 mg daily over long periods) can cause nerve damage, with loss of balance and numbness in the feet and hands. Food sources of vitamin B6 include meats, oily fish, poultry, whole grains, dried fortified cereals, soybeans, avocados, baked potatoes with skins, watermelon, plantains, bananas, peanuts, and brewer's yeast.

Vitamin C. Ascorbic acid (vitamin C) may change in the body to tiny crystals, called oxalates. These crystals do not dissolve. People with hyperoxaluria (too much oxalate in the urine) should avoid vitamin C supplements. Even for men with normal oxalate levels, higher consumption of vitamin C (more than 1,000 mg a day) may increase kidney stone risk.

Magnesium and potassium may help reduce the risk for kidney stones in men.

Because of an association between stress and kidney stones, relaxation and stress management techniques may also be beneficial.

Dietary Considerations. People with kidney stones appear to be more sensitive to certain foods than people who do not form kidney stones. Therefore, vulnerable people should make specific changes in their diet. They should work with their doctors to develop a dietary plan that fits their individual situation. Drinking plenty of fluids is important for preventing recurrence of any kidney stone.

Indications for Drug Treatments. If dietary treatments fail, drug therapy may be helpful. A number of drugs are available to prevent recurrences of calcium oxalate and other stones. Medications that inhibit the formation of stones include allopurinol, thiazide, potassium citrate, and potassium-magnesium citrate. In addition, drug treatments can sometimes also help prevent other complications related to stones, such as osteoporosis.

Correcting Underlying Conditions Known to Cause Kidney Stones. It is also important to treat and correct, if possible, any underlying disorder that may be causing stones to form. Such disorders include distal renal tubular acidosis, hyperthyroidism, sarcoidosis, and certain cancers. To prevent calcium stones that form in hyperparathyroid patients, a surgeon may remove the affected parathyroid gland (located in the neck). In most cases, only one of the glands is enlarged. Removing it ends the patient's problem with kidney stones.

Resources

www.kidney.niddk.nih.gov -- National Kidney and Urologic Diseases Information Clearinghouse
www.urologyhealth.org -- American Urological Association
www.kidney.org -- National Kidney Foundation
www.ohf.org -- Oxalosis and Hyperoxaluria Foundation

References

Cameron MA, Maalouf NM, Adams-Huet B, Moe OW, Sakhaee K. Urine composition in type 2 diabetes: predisposition to uric Acid nephrolithiasis. J Am Soc Nephrol. 2006 May;17(5):1422-8. Epub 2006 Apr 5.

Curhan GC, Willett WC, Knight EL, Stampfer MJ. Dietary factors and the risk of incident kidney stones in younger women: Nurses' Health Study II. Arch Intern Med. 2004;164(:885-891.

Finkielstein VA. Strategies for preventing calcium oxalate stones. CMAJ. 2006;174(10); 1407-1409.

Krambeck AE, Gettman MT, Rohlinger AL, Lohse CM, Patterson DE, Segura JW. Diabetes mellitus and hypertension associated with shock wave lithotripsy of renal and proximal ureteral stones at 19 years of followup. J Urol. 2006;175(5):1742-7.

Sinha MK, Collazo-Clavell ML, Rule A, et al. Hyperoxaluric nephrolithiasis is a complication of Roux-en-Y gastric bypass surgery. Kidney International. 2007;72:100-107.

Straub M, Hautmann RE. Developments in stone prevention. Curr Opin Urol. 2005;15(2):119-126.

Taylor EN, Stampfer MJ, Curhan GC. Dietary factors and the risk of incident kidney stones in men: new insights after 14 years of follow-up. J Am Soc Nephrol. 2004;15(12):3225-3232.

Taylor EN, Stampfer MJ, Curhan GC. Fatty acid intake and incident nephrolithiasis. Am J Kidney Dis. 2005;45(2):267-274.

Taylor EN, Stampfer MJ, Curhan GC. Obesity, weight gain, and the risk of kidney stones. JAMA. 2005;293(4):455-462.

Taylor EN, Stampfer MJ, Curhan GC. Diabetes mellitus and the risk of nephrolithiasis. Kidney Int. 2005 Sep;68(3):1230-5.

Wasserstein AG. Nephrolithiasis. American Journal of Kidney Diseases. 45(2);2005:422-28.

Review Date:
7/24/2007
Reviewed By:
Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.

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adam.com

Reader Recipe: Roasted Salmon with Cucumber Tomato Dill Salad

YumSugar — Wed, 13 Jun 2007 13:13:13 -0700

I was checking out all the great recipes over on TeamSugar and came across this gorgeous roasted salmon with cucumber, tomato & dill salad posted by friedwonton. It looks perfect for a light summer meal, and I love how all the color jumps off the plate. Speaking of plate, she's even included plating directions in her recipe! To check it out, read more

This recipe was submitted by TeamSugar member friedwonton:

Ingredients
1/4 lb of salmon filet
1 lemon
1/2 tomato (you can also use grape or cherry tomatoes as well)
1/4 of a small red onion
1/2 cucumber
spring mix greens
white vinegar
olive oil
fresh dill
kosher or sea salt
ground pepper

Serving: 1

Cucumber Tomato Dill Salad
1) Cut the red onion in medium thick slices.
2) Cut the tomato into 4 wedges. If you are using grape or cherry tomatoes, cut them in halves.
3) Cut the cucumber in half and then at an angle.
4) In a large bowl, add a splash of white vinegar and a drizzle of olive oil. Mix well.
I do not measure the amount of vinegar and olive oil I use, but always start with a small amount and then slowly increas the ingredients depending on your taste level.
5) Add a pinch of salt to taste. Mix well.
6) Add the fresh dill.
7) Placed the onion slices, tomatoes, and cucumber into the bowl. Coat well.
8 ) Place the salad aside in the refrigerator.
This salad can be made the day before and actually taste a lot better as it gets the chance to marinate.

Roasted Salmon
1) Preheat oven to 400 degrees F.
Don't feel like heating up the big kitchen oven? You can roast the salmon in a toaster over (as I did for the picture above), cook it on the grill, or on the stove.
2) With a zester, zest half of the lemon. Set aside.
3) After zesting, cut the lemon in half.
4) Cut medium thick slices of the half lemon. Set aside
5) Drizzle and rub olive oil on the salmon.
6) Salt and pepper it all over.
7) Create a little bed of lemon slices on the roasting pan for the salmon.
8 ) Place in the oven.
For a 1/4 lb of salmon it will usually takes 12 to 15 minutes, depending how well you like your salmon to be cooked.

Plating
1) Place the salmon with the bed of lemon on one side of the plate.
2) Lightly squeeze a little bit of lemon juice on the salmon.
3) Garnish with lemon zest and a slice of lemon on top.
4) Place the spring mix greens next to the salmon.
5) Top the bed of spring mix with the cucumber tomato dill salad.
6) ENJOY!!