Is Gluten Really the Enemy?

Monday, June 15, 2015

Shannon Lewis, MD

Gluten has gained a great deal of attention over the past decade, the majority of which has been negative. It is has been blamed for causing a wide array of clinical symptoms, most commonly gastrointestinal distress, including abdominal bloating, cramping, and changes in bowel habits. The gluten-free diet has become the hottest fad diet in the United States. However, the question needs to be asked – is gluten really the enemy?

For a subset of people, gluten (a protein that is found in grains such as wheat, barley, and rye) has been scientifically proven to be harmful. Approximately 1 in 133 Americans have celiac disease, an autoimmune disorder in which gluten triggers an immune response. This leads to damage of the intestinal lining and, subsequently, results in malabsorption of nutrients. A diagnosis of celiac disease is made based on serologic testing as well as small bowel biopsies. If untreated, complications can be broad, including bone density loss, infertility, neurologic symptoms, and anxiety/depression, to name a few. The only current treatment option is a strict, life-long avoidance of gluten, although other potential treatment modalities are being investigated.

Another entity referred to as Non-Celiac Gluten Sensitivity (NCGS) has gained significant recognition over the years. NCGS is defined as the occurrence of gastrointestinal symptoms, similar to those experienced in irritable bowel syndrome (such as gas/bloating and irregular bowel habits), after ingestion of gluten, and subsequent improvement in these symptoms with elimination of gluten from the diet. In contrast to people with celiac disease, ingestion of gluten-containing foods does not cause serious, long-term effects for those with NCGS. No diagnostic testing exists for this disorder, but celiac disease is not the cause of distress for these people.

A newer concern is that of FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols), or poorly absorbed carbohydrates (sugars) that are found in various foods. FODMAPs include:

  • Fructose, found in some fruits and honey
  • Fructans, found in wheat, garlic and onions
  • Galactans, found in beans and legumes
  • Lactose, found in dairy products
  • Polyols, found in sweeteners

Fermentation of carbohydrates by intestinal bacteria leads to gas production, which results in abdominal bloating, pain, and altered bowel movements. A recent study looked at 37 patients with NCGS, in which celiac disease had been ruled out. When all 37 people were taken off of food that contained FODMAPS, their symptoms improved significantly. When they reintroduced only gluten and not the other FODMAP foods, only 8% of the 37 people actually reacted to gluten.

This data raises the possibility that many people thought to have NCGS are actually intolerant of FODMAPs, and that the prevalence of NCGS may have been widely overestimated. It is interesting to think that “gluten sensitivity” may not be caused by gluten at all, and perhaps the question that we really need to be asking is, “Are FODMAPs the true enemy?”