By Talia Machlouf

In recent years, the gluten-free diet has become a fad diet that boasts a variety of health benefits, both factual and false. Despite celiac disease affecting just 1% of the population, surveys show that approximately 20% of consumers avoid gluten. Improved cognitive function (reducing brain fog) is one of the many presumed health benefits of the gluten-free diet for the general population. But a recent study published in JAMA Network, using two decades worth of dietary data, concluded that gluten consumption in people without celiac disease did not impair cognitive function.

Despite celiac disease affecting just 1% of the population, surveys show that approximately 20% of consumers avoid gluten.

Using the Nurses’ Health Study II – a nationwide, prospective cohort of female nurses aged 25-42 upon enrollment in 1989 – the study, led by Dr. Andrew Chan, a Professor of Medicine at Harvard Medical School and Vice Chair of Gastroenterology at Massachusetts General Hospital, gathered data on 13,494 women without celiac disease through twice-yearly questionnaires, as well as dietary surveys collected every four years since 1991. Using a validated Food Frequency Questionnaire (a list of foods and beverages with response categories to indicate typical consumption frequency over a specific period of time), the study estimated participants’ long-term gluten intake, and divided the estimated gluten intake into five groups (quintiles) – 0.1 to <5.1, 5.1 to <5.9, 5.9 to <6.6, 6.6 to <7.6, and 7.6 to 18.3 grams/day. A validated, self-administered, online Cogstate Brief Battery designed to assess mild cognitive impairment was used to evaluate participant cognitive function.

When analyzing cognitive function scores across the quintiles of gluten intake, and after adjusting for several behavioral and health risk factors, the researchers “observed no difference in psychomotor speed and attention score, learning and working memory score, and global cognition score,” which were the three measurements of the cognitive battery. Based on these study results, lead author, Dr. Chan, explains that people who do not have celiac disease “should not pursue a gluten-free diet under the assumption that they will improve their brain health. The evidence is simply not there to support modifying one’s diet for this purpose.”

Cognitive symptoms (brain fog) are often reported by celiac disease patients prior to their diagnosis, as well as after accidental gluten consumption. Although popular opinion indicates that gluten consumption can impair cognitive function, this study, using two decades of information from middle-aged women without celiac disease, found no association between gluten intake and cognitive decline in the general population. This is good news for women without celiac disease who may consume gluten without worrying about associated cognitive impairment.

To view the original study, click here.