Tuesday, September 23, 2014

Gluten-Free Diet: The Truth Behind the Trend

A diet void of wheat, rye, barley (and oats only occasionally)… The Gluten-Free Diet seems to be all the rage these days. What began as a simple treatment for an autoimmune disease has now become one of the most well-known diets in America. Not surprisingly, it has also become a food market goldmine, with GF sales expected to exceed over $5 billion by 2015. We’ve all heard the hype about how gluten-free foods are overall better for you, can help you lose weight, sleep better, give you more energy, clear up your acne and even improve medical conditions such as autism and rheumatoid arthritis. It can be difficult to sift through the mounds of messages that the media and food manufacturers have put forth touting the many health benefits of eliminating gluten from your diet. But is there any truth behind these claims? And if so, are they really worth eliminating some of the most delicious foods in your diet and dishing out extra money for gluten-free foods? Read on to discover the truth about gluten and whether or not you can benefit from a gluten-free diet.

What is gluten? 
It’s a protein composite of gliadin and glutenin found in wheat, rye, barley and triticale. Functionally, it helps food maintain its shape and gives dough elasticity and chewiness. It is also used as a thickener for many foods.

Who should avoid gluten?
In short, anyone who has been diagnosed with Celiac Disease (CD) or Non-Celiac Gluten Sensitivity (NCGS) should avoid gluten. CD is a genetic, autoimmune disorder where the ingestion of gluten leads to damage in the small intestine. This causes malabsorption of almost all nutrients and can lead to very serious health consequences, such as weight loss, slowed growth and even death in severe cases. CD can be diagnosed by a combination of a blood test checking for antibodies to gluten and small bowel biopsy looking for damage to the intestinal cells. It is estimated that 1 in every 105 people in the US have CD.

A much less severe but more common condition related to gluten is Non-Celiac Gluten Sensitivity (NCGS). Current estimations indicate a 3-6% prevalence of NCGS in the US. While there is no definitive way of diagnosing NCGS, it is recognized by symptoms similar to those of celiac disease that improve when gluten is eliminated from the diet. Individuals with NCGS would not produce the same antibodies or have the intestinal damage as seen in CD. Some of the symptoms caused by NCGS include stomach pain, gas, diarrhea, extreme tiredness, “foggy mind” and bone/joint pain. Since there is no blood test for gluten sensitivity, the only way to be diagnosed is to undergo the screening and diagnostic tests required to confirm celiac disease. A diagnosis of gluten sensitivity is confirmed when/if the celiac disease or wheat allergy test are negative, and your symptoms diminish after starting a gluten-free diet, followed by a return of symptoms when gluten is reintroduced into your diet. There is no cure for gluten sensitivity or celiac disease, and the only treatment is to follow a gluten-free diet.

Those with a wheat allergy may also benefit from a gluten-free diet, because it is free of wheat. It is important to note, however, that this is an adverse immunologic reaction to wheat, NOT gluten. Wheat is the 8th most common food allergen in the US, and is more common among children than adults. Immediate symptoms of wheat allergy include: hives, airway obstruction, nausea, or gastrointestinal complaints. Delayed reaction may present 24 hours after ingestion with gastrointestinal complaints, itching and rash.

Gluten-Free for weight loss?
According to a reputable review article posted in the Journal of the Academy of Nutrition and Dietetics, there is no evidence suggesting that a gluten-free diet produces weight loss in people with or without CD or NCGS. In fact, for overweight or obese patients with CD, body weight may increase on a gluten-free diet. This is likely due to the fact that some gluten-free products have greater energy value than corresponding gluten-containing foods. Also, a gluten-free diet may lack whole grains and fiber, both of which have been shown to be associated with healthy weights.

Gluten-free for other health benefits? 
A commonly held belief among Americans is that gluten-free foods can improve gastrointestinal health. Data, however, suggest that this is not true. Naturally occurring starches in wheat, such as oligofructose and inulin, are beneficial for creating a healthy composition of gut bacteria. These “good” gut bacteria are known to have protective effects for some cancers, inflammatory conditions and cardiovascular disease. Recent evidence suggests that a gluten-free diet may lead to reductions in “good” gut bacteria and vice-versa… that increasing whole-grain wheat intake has been reported to increase “good” gut bacteria. This data supports the well-established, inverse relationship between whole-grain food intake and risk of cardiovascular diseases.

Additionally, a study published in the American Journal of Clinical Nutrition showed the potential benefits of gluten for improving blood lipid levels, and another article published in 2011 suggests that gluten may help control blood pressure. Other research studies indicate the potential role of gluten in boosting the immune system.

Bottom Line:
GF diet is clearly indicated for CD and NCGS
No evidence to suggest that following a GF diet has any significant benefits in the general population
Going gluten-free for purposes of weight loss may have unintended consequences
No data to support a weight loss claim for a gluten-free diet

~ Ashley Hamm, MS, RD


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Marcason, W. Is there evidence to support the claim that a gluten-free diet should be used for weight loss?. J Am Diet Assoc. 2011; 111: 1786

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Rubino J. 7 gluten-free statistics you need to know. New Hope Website. Accessed Sept 15, 2014. Updated May 20, 2013. Available at: http://newhope360.com/managing-your-business/7-gluten-free-statistics-you-need-know.

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