How Sport Drinks And (gasp) Beer Might Impact Your Gut Health

by Kami Semick

There is a trend of late that you may have noticed, the trend towards gluten-free and paleo diets in both the general population as well as elite athletes.  It seems like every product these days is marked with “Gluten Free” or “Paleo Friendly.”  The general population as well as many athletes of all levels have consciously chosen to avoid gluten because they believe it will lead to better health and the avoidance of GI issues.  This movement away from gluten has bled itself into grain avoidance all together, making paleo an increasingly popular dietary choice.

But Doctor Christine McDonald, a scientist at the Cleveland clinic, has discovered that maltodextrin, often the primary if not sole ingredient in sports drinks and energy gels, might be a major player in changing the chemistry of your GI and may pave the way towards irritable bowel syndrome and Crohn’s disease, one the conditions gluten free and paleo advocates seek to avoid.  Running with an upset GI can be inconvenient, but Crohn’s disease can be debilitating and life threatening.   Even if you are not partaking in sport drinks or energy gels, know maltodextrin is added to everything from potato chips to low fat peanut butter to beer.

Imagine my surprise while reading an opinion piece in the New York Times “The Germs That Love Diet Soda” that connected my sports energy drink and gel use to an altered and unhealthy GI. Expecting to read about how diet soda is making us fat (which it is, please read the article), I stumbled upon the section about Dr. McDonald’s research into maltodextrin, a primary ingredient in most sport energy products.

According the Cleveland Clinic, “Maltodextrin is a starch-derived food additive that is commonly used as a thickening, coating or filling agent. It’s found in thousands of food items including sports drinks, artificial sweeteners, potato chips, salad dressing and beer.”


What is it about maltodextrin that can lead to GI issues?  According to Dr. McDonald, the GI tract of healthy people has a thick mucus layer which helps unhealthy bacteria from sticking.  But people with inflamed bowel disease have thinner mucus layers.  The thinning of the mucus layer as observed by Dr McDonald can be an adaptation to maltodextrine.

The idea is that the more one consumes maltodextrin, the more the body adapts to processing it in order to extract out the most energy.  The body adapts by thinning the mucus layer and altering the bacteria in the GI tract which leads to the demise of overall gut health.  So even if you don’t have the extreme condition of Crohn’s disease, maltodextrin can lead to a path of an altered, unhealthy GI microbiome.

As an athlete, I think about what goes into my body.  While I don’t follow any specific diet, I avoid packaged foods and eat a mostly unprocessed diet sourcing as much as possible from local farms and ranches.  Except when I’m running.  Slow long runs I can get by on solid food, but anything fast or long, I usually turn to gels or sport drinks.

Before reading the NYT article, one of my primary source of calories when racing was Carbo Pro. Carbo Pro is marketed as a tasteless complex carbohydrate in the form of a powder that can be mixed into water.  Specifically Carbo Pro’s ingredient label lists “glucose polymers derived from non GMO corn.” Translated, the ingredient is 100% maltodextrin.  Speaking from personal experience, early in my running career I didn’t have a problem with Carbo Pro or any gel.  Then I seemed to build up an intolerance.  Now I know why.

I started looking at other popular sport gels and drinks.  According to GU’s website, “GU Brew, GU Energy Gel, Roctane, and Chomps are all made of a mix of maltodextrin and fructose.”  Cliff Bar puts a healthy spin on it by using “organic maltodextrin” as the primary ingredient in their popular Cliff Shots.

Oh, and that beer after the race can possibly add insult to injury.  Maltodextrin is added by some brewers to increases the body and “mouth feel” of beer.

Where do we go from here?  The best thing to do is ask questions, read labels, and eat whole foods.  But I’d be curious to hear if anyone has a maltodextrin free energy gel that they could recommend when a run (or hike, or bike) goes long.