Many people without celiac disease feel better when they avoid gluten. But it turns out that gluten may have nothing to do with it. Nutrition Diva explores the latest research
Many people without celiac disease feel better when they avoid gluten. But it turns out that gluten may have nothing to do with it. Nutrition Diva explores the latest research
I'm sure you've noticed, gluten-free diets have become wildly popular, even among those who do not have Celiac disease. With all the models and actresses insisting that shedding gluten keeps them thin and top tennis pros claiming that avoiding gluten improves their stamina, it's no wonder that gluten-free has become a major diet trend.>
Despite all this, many experts insist that there is no reason for people without Celiac disease to avoid gluten. For one thing, avoiding gluten does not automatically lead to weight loss. Many people, in fact, gain weight when they go gluten-free, for reasons I explored in my episode on gluten-free diets. Cutting out wheat and other gluten-containing grains can also increase the risk of certain nutrient deficiencies if you're not paying attention. Suffice it to say that a gluten-free diet is not automatically a healthy diet - nor is it a cure-all.
On the other hand, many people who suffer from Irritable Bowel Syndrome (IBS) find that their symptoms improve on a gluten-free diet - even when they do not have Celiac disease. This is so common, in fact, that the medical profession has assigned a name to the phenomenon: Non-Celiac Gluten Sensitivity (NCGS). But an interesting new study finds that gluten may not be the culprit after all.
The study design and findings are a little complex and difficult to sum up in a catchy sound-byte. But with all the hoopla about gluten these days, I think it's worth describing this study in a bit of detail, so that you can really understand the implications.
For this study, researchers recruited IBS patients who did not have Celiac disease but appeared to be sensitive to gluten. These patients were already following a gluten-free diet because it helped reduce their symptoms. For the study, they were asked to switch to a low FODMAP diet instead. On a low FODMAP diet, you avoid a particular list of fruits, vegetables, and grains - including wheat. The idea isn't to avoid gluten (which is a protein), but rather to avoid certain fibers and other carbohydrates that are difficult to digest.
Even though they were already doing pretty well on a low-gluten diet, all of the subjects reported significant improvement on the low FODMAPs diet. So far, so good! Then, the researchers introduced either gluten, whey protein, or a placebo containing no protein at all. At this point, a lot of people's symptoms got worse. But gluten was no more likely to produce symptoms than whey or placebo.
Then, they did something very interesting.....
They repeated the study a few weeks later, using the same subjects. The overall results were similar: the same percentage of people responded poorly to each of the interventions. But interestingly, many of the people who had responded poorly to gluten the first time had no trouble with gluten the second time. Instead, they either had no increase in symptoms or they had an increase in symptoms to whey protein or to the placebo.
What does this tell us? Well, I guess it tells us that people with IBS have very sensitive tummies. But it also suggests that for most of them, gluten is not a unique or reliable trigger. When they crunched all the numbers, the researchers concluded that actual gluten sensitivity (defined as a unique and reproducible response to gluten) was present in fewer than 10% of people who described themselves as sensitive to gluten.
There's one other aspect of the study that deserves mention. Many people - such as the authors of recent best-sellers like Wheat Belly and Grain Brain - claim that gluten irritates and damages the lining of the intestines, causing a condition sometimes described as "leaky gut." So, in addition to asking subjects to record and rate their symptoms, the researchers also did extensive blood work, looking for signs of immune activation, intestinal inflammation, or increased gut permeability. For what it's worth, these researchers did not observe any signs of these effects in response to gluten.
All of this, of course, is very interesting to researchers and those who study nutrition science. But what if anything, can we take away from this research in terms of real-world applications? For me, there are two take home lessons for those who suspect that they are gluten sensitive: