I recently had the opportunity to watch Rachel Freire, a Brazilian postdoctoral researcher at Mucosal Immunology and Biology Research Center/Center for Celiac Disease at Massachusetts General Hospital/Harvard Medical School present her latest paper, Wheat gluten intake increases weight gain and adiposity associated with reduced thermogenesis and energy expenditure in an animal model of obesity. Gluten free diets have been discredited as a “fad” even though so many people report not only feeling better but also losing weight. Non-celiac gluten sensitivity is no longer a diagnosis of quackery, but a legitimate condition. Gluten free diets have been studied for the prevention and treatment of conditions like type 1 diabetes, rheumatoid arthritis and multiple sclerosis.
Gluten free diets for weight loss however, have not been heavily studied. Freire referenced a 2013 study conducted on mice. The researchers concluded the following:
“Our data support the beneficial effects of gluten-free diets in reducing adiposity gain, inflammation and insulin resistance. The data suggests that diet gluten exclusion should be tested as a new dietary approach to prevent the development of obesity and metabolic disorders.”
A search of other papers related to “weight” or “adiposity” plus the term “gluten” yielded no further results, except this a 2005 study, Agrarian diet and diseases of affluence–do evolutionary novel dietary lectins cause leptin resistance? The lab conducted a study on 24 domestic pigs in which a “cereal-free hunter-gatherer diet promoted significantly higher insulin sensitivity, lower diastolic blood pressure and lower C-reactive protein as compared to a cereal-based swine feed.” The implications of the study were summarized by the researchers:
“An agrarian diet initiates diseases of affluence it should be possible to identify the responsible constituents and modify or remove them so as to make an agrarian diet healthier.”
In Freire’s study, mice were fed for eight weeks one of four isocoloric diets: a standard, control diet which was gluten free (CD), the same standard diet with gluten added (but controlled for total carbohydrates and calories) (CD-G), a high fat diet, gluten free (HFD), and a high fat diet with gluten added (again, controlled for total carbohydrates and calories) (HFD-G). The fat used was lard. Freire tested the mice using indirect calorimetry (measuring Co2 breathed out by the mice), their total fat, their and their percentage of brown fat. She found that the mice in both groups that consumed the gluten gained more total weight, had more liver and visceral fat, and had lower energy expenditure (were less active). The mice had a higher proinflammatory profile with higher leptin, higher TNF and reduced adiponectin and lower thermogenesis and browning of fat tissue.
Basically, she proved that gluten makes mice fat.
Does this mean that gluten is the devil? Not necessarily. In our world of highly processed, hyper palatable foods contributing to about 60% of our caloric intake, perhaps we’re just eating way too much. Maybe our baseline inflammation levels are already heightened from other foods, stress, and imbalanced microbiome, making us more sensitive to the damages of gluten. By cutting out gluten, you’re cutting out nearly all of the processed foods on the market. This could be part of the solution. The way we grow and prepare gluten today is also much different than the way our grandmothers did it. It’s no longer allowed to ferment, removing much of the gluten and making it more digestible. Some people also think that GMO gluten, sprayed with herbicides like glyphosate may play a factor. Glyphosate has been listed as a class 2 carcinogen, has been shown to contribute to disease.
In my opinion, it’s great to include as many foods as possible into the diet, with the least amount of distress. For some people, this means the complete elimination of gluten, while for others, limited amounts of properly prepared gluten foods (traditionally fermented as in sourdough) may be fine. Genes, stress levels, sleep hygiene, gut flora, and many other factors all play into how our bodies handle gluten and other foods. I think it’s time the US Dietary Guidelines Committee addressed the impact of processed foods on our health, as Brazil has done.
The bottom line: If you’re sick, inflamed, and overweight, you may benefit from a 30-day removal of gluten to see how you feel.