Wheat and gluten have gotten a bad rap recently for being “inflammatory” food ingredients, and they are considered to have a negative effect on an athlete’s (or anyone’s) general health, as well as recovery from hard exercise. It’s impossible to miss the plethora of gluten-free options available at almost any supermarket.
Currently, experts estimate that 5 to 10 percent of the population would benefit medically from a gluten-free diet due to celiac disease, the more recently identified “non-celiac gluten sensitivity,” and of course, wheat allergy. But what if an athlete has none of these real conditions? Would taking wheat out of your diet improve your performance for other reasons?
Many athletes believe that sifting the wheat out of their diet could result in a performance boost. A recent survey of over 900 predominantly endurance athletes (ranging from recreational level to Olympic medalists) conducted by researchers from Canada and Australia found that the gluten-free trend far exceeds the estimates of people who have celiac disease, gluten sensitivity, and wheat allergy. Of those surveyed, over 40 percent followed a gluten-free diet more than 50 percent of the time. This number jumped up to 70 percent among recreational endurance athletes. More than half was based on a self-diagnosed gluten issue rather than clinical recommendations from a health care professional. Major reasons for eliminating gluten were a perception of less gastrointestinal distress, reduced inflammation, improved exercise performance, and improved body composition.
Given the widespread prevalence of going gluten-free, these same researchers designed a study to measure the performance and health benefits of a short-term gluten free diet. They placed 13 competitive cyclists on either a gluten-free or gluten-containing diet by using two similarly tasting sports bars along with other foods; one bar contained gluten and one did not. The gluten-containing diet involved a hefty gluten dose and neither the athletes nor the researchers knew when they were on or off gluten. None of the cyclists had any known gluten sensitivities.
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At the end of each week on either diet, the cyclists performed a strenuous time trial test and the scientists checked for a marker of intestinal inflammation. Their results indicated that a short-term gluten-free diet had no effect on performance, GI symptoms, sense of well-being, or a select set of inflammatory markers of intestinal injury in the endurance athletes. So far, no hard evidence that all endurance athletes should swear off wheat or gluten exists.
But what about the athletes who have truly benefited from going gluten-free? It is likely that some of them may fall somewhere on the gluten/wheat spectrum. Clearly athletes with celiac disease need to adhere to a lifelong gluten-free diet to prevent serious adverse health effects, irrespective of striving for their best athletic performance.
What if you adopt a gluten-free diet just to try it out? Taking wheat out of your diet is no guarantee that you will improve the quality of your diet; it depends more on what choices you make next. Whole wheat products provide nutrients and fiber and may be fortified with B vitamins and iron. They should be replaced with wholesome carbohydrates that are also nutrient and fiber rich. And, while gluten-free products provide an important service, these products may not contain much fiber, vitamins, or minerals, and can be higher in calories than their gluten friendly counterparts.
Before you self-diagnose, let’s take a look at the spectrum of reactions and how they are identified.
Celiac Disease (CD)
Celiac disease (CD) affects about one to one and a half percent of the population worldwide, including more than two million people in the United States. It is an autoimmune condition that occurs in a person with a genetic susceptibility and an unusually permeable gut. Part of the diagnosis is a blood panel that includes an antibody test, as well as an intestinal biopsy performed by a qualified physician.
It is currently estimated that only 15 percent of Americans with CD are diagnosed. If you eliminate gluten long enough before testing for celiac disease, the celiac tests are invalid. Gastrointestinal symptoms are present in persons diagnosed with CD only 30 to 40 percent of the time. Most people who have eliminated gluten and feel better do not want to go back on gluten for the needed eight weeks to get the proper testing to rule out CD. It is important to distinguish between CD and non-celiac gluten sensitivity, as untreated CD clearly has serious health risks.
Non-celiac gluten sensitivity (NCGS)
NCGS is estimated to affect anywhere from 5 to 10 percent of the population. There is no validated test to diagnose NCGS. NCGS is diagnosed when celiac disease has been excluded through proper testing, and when ingesting gluten triggers symptoms and removing gluten brings relief of those symptoms.
The mechanism for developing NCGS has not been determined (but is under intense study). The reaction may be due to the carbohydrate component of gluten or to proteins present in gluten. It does not appear to be an autoimmune reaction though the symptoms are similar to CD. There may be a greater prevalence of non-GI symptoms such as fatigue, bone or joint pain, muscle cramps, headaches, leg numbness, brain fog, and anemia in NCGS (symptoms also found in celiac disease).
It is not known if the gluten-free diet for NCGS needs to be as strict as in CD, or if the same risk of complications occurs, or if the diet needs to be lifelong.
Wheat allergy (WA)
This is an immune reaction to wheat proteins and is considered a classic food allergy in which Immunoglobulin E (IgE) antibodies play a role. The reaction to wheat is immediate and severe. WA affects the skin, lung, and respiratory systems. Other classic common allergens are peanuts, milk, eggs, fish, nuts, and soy. Only 3 to 4 percent of adults have true food allergies. Allergists and immunologists use skin tests to identify food allergies.
Food sensitivities also involve the immune system, but the classic IgE antibodies of an allergy are not present. These reactions tend to be less severe and can occur several hours after the food is ingested. They do have an immune response that releases a number of biochemical mediators into the bloodstream which can cause localized inflammation resulting in a wide array of symptoms, including GI symptoms, headaches and migraines, sinus congestion, general fatigue, excess mucus production, joint pain, and muscle soreness. People can develop sensitivity to any food, including wheat, and they are more prevalent than allergies, occurring in up to 20 percent or more of the population. Certain blood tests check for sensitivities such as the mediator release test (MRT). These results are then verified with an elimination diet guided by a trained dietitian. Sensitivities are often incorrectly called intolerances, such as “gluten intolerance,” which is really gluten sensitivity.
Food intolerances do not involve the immune system but interfere with the digestion and absorption of food. Frequently these intolerances involve carbohydrate-containing foods. Lactose intolerance in which an individual lacks the enzyme lactase needed to break down lactose or milk sugar is one example. Fructose is another possible intolerance. Wheat contains carbohydrates that may not be tolerated by some individuals with a sensitive gut or even irritable bowel syndrome, as can other carbohydrate containing foods.
Often, small amounts of intolerant foods can be consumed; you just can’t consume too much—for you. When a food can’t be fully digested it sits in the gut where microorganisms happily feed on the undigested food and cause bloating, gas, and pain. The body attempts to dilute this concentrated mess by drawing more fluid into the gut, resulting in diarrhea.
Endurance athletes who consume high levels of fructose during training may put themselves at risk of GI upset. Most sports drinks contain smaller amounts of fructose, which is easily absorbed along with glucose during exercise for optimal performance benefits. Endurance athletes should also take note that low-calorie products that contain sugar substitutes like sorbitol or xylitol can lead to poor absorption as this can also risk GI upset.
If you do suspect that foods are causing some health concerns such as gastrointestinal symptoms or other problems that interfere with your training and recovery, it is important that you are evaluated and tested by the appropriate health care professional(s). But beware the pitfalls of taking wheat or gluten out of your diet on your own when the serious condition of celiac disease remains under-diagnosed.
See what to eat and when with Sports Nutrition for Endurance Athletes. Monique Ryan demystifies optimum daily nutrition and shows simple steps to make the best decisions about what you eat and drink.