Upset Stomach Got You Down? It May Be 1 of These Common Smoothie Ingredients

It's safe to say at this point that pretty much every dessert recipe under the sun has been made into a smoothie. You can make a Banana Bread Smoothie, a Chocolate Banana Cashew Smoothie, or even a better-for-you Strawberry Milkshake.

While there's nothing wrong with dessert, if you often experience symptoms of digestive distress (like bloating, nausea, gas, burping, or diarrhea), the ingredients in your daily smoothie could very well be to blame. Whether due to an allergy, intolerance, or other underlying issue, these symptoms are no fun at all, and can potentially be avoided by switching what you whiz up in the blender.

With the help of holistic nutrition consultant Julia Visser, we're breaking down five of the biggest offenders, and some totally legit replacements, so your smoothie can start loving you back.

Dairy
POPSUGAR Photography | Lexi Lambros

Dairy

Milk, yogurt, and cottage cheese are common smoothie ingredients, but they don't work well for everyone. Approximately 65 percent of the world population has a decreased tolerance to lactose (the sugar found in milk products). Visser notes that, "Conventional dairy can be very inflammatory from the denatured proteins that our bodies often mark as allergenic, to the poor food, hormones, and antibiotics fed to the cows. This can cause a cascade of inflammation and possible gut-related issues."

The good news is that there are loads of alternatives, and many of them are available at major grocery stores. If you are simply looking for a high-quality, organic dairy milk, Organic Valley is a good option. You could also swap out dairy milk for almond, cashew, or coconut milk, and yogurt for a nondairy variety.

Psst . . . you should try out a few of these dairy-free smoothie recipes while you are at it.

Peanut Butter
StockSnap | Krzysztof Puszczyński

Peanut Butter

Symptoms of a peanut allergy are severe enough that you probably already know if you have one, but eating too many peanuts can cause tummy troubles even if you don't have an allergy. Peanuts, like many beans and legumes, contain phytic acid and lectins. These compounds make peanuts difficult to digest (think of it as the peanut's defense mechanism), and eating too many peanuts (or spoonfuls of peanut butter) can cause unpleasant symptoms like gas and bloating.

Almond butter, walnut butter, or tahini (sesame seed butter) are lower in lectin than peanut butter, so they make for a good substitute. If you really want to test the effects of phytic acid on your digestion, soak and sprout nuts at home or purchase sprouted nuts from a health food store.

Whey Protein Powder
Unsplash | Oscar Nord

Whey Protein Powder

Protein powder has become a smoothie staple for the gym-going set, but whey protein powder can be problematic for certain people. Visser shared that, "Whey can be allergenic for a lot of people, which may stimulate inflammation."

If you have a dairy allergy or lactose intolerance, you'll be better off seeking out a nondairy protein source. Protein powder made from egg whites, collagen, or beef protein isolate (don't worry, it's flavored) are good alternatives. If you are looking for vegan options, try pea or hemp protein (and then try this plant-based Carrot Cake Smoothie).

Soy Milk
StockSnap | Andrew Weber

Soy Milk

Thanks to its high protein content, soy milk is a typical smoothie alternative for those who can't do dairy. Obviously, you probably already know if you break out in hives when you eat or drink soy products, but some people who aren't allergic still have trouble digesting the protein in soy. If this is you, soy products may cause some, ahem, not-so-fun digestive symptoms.

No need to fret, though. Soy milk can be replaced cup-for-cup with almond milk, coconut milk, or even rice milk. These milks are not as high in protein as dairy or soy milk, however, so make sure you are getting your protein in elsewhere.

Coffee
StockSnap | Matthew Henry

Coffee

I don't know who the genius is that brought coffee and smoothies together, but I would thank them personally if I could. Unfortunately, in the same way coffee wakes you up in the morning, it also wakes up your digestive system.

Everybody's tolerance to caffeine is different, but most people are safe with one or two cups per day. As long as you keep it in check, a little coffee in your smoothie shouldn't be an issue. If you do notice that you need to go righthisminute, try a coffee-free smoothie like this one.