Women without celiac disease appear not to differ in their cognitive function based on the amount of gluten in their diets, a U.S. study finds. Researchers examined data on 13,494 women (mean age 60.6 years) who participated in the Nurses' Health Study II and had no baseline or subsequent diagnosis of celiac disease. Gluten intake was calculated based on food frequency questionnaires completed every four years up to 2015, and standardized cognitive scores were calculated based on annual scores from 2014-2019 on the Cogstate Brief Battery for psychomotor speed and attention, learning and working memory, and global cognition. Mean gluten intake was 6.3 grams per day. There were no significant differences in standardized cognitive scores between the highest and lowest quintiles of gluten intake, the study team reports in JAMA Network Open. "We found that among individuals without a history of celiac disease, a low gluten diet was not associated with any improvement in cognitive function," said senior study author Dr. Andrew Chan, a professor at Harvard Medical School and gastroenterologist at Massachusetts General Hospital in Boston. "I do not think this was a surprise since there really was no evidence to support the popular concept that gluten was harmful to the general population," Dr. Chan said by email. The absence of any association between gluten intake and cognitive function persisted even when researchers adjusted the analysis to focus on major sources of dietary gluten such as refined grains or whole grains. There was also no association when researchers excluded the subset of women who had a dementia diagnosis or reported cancer or who failed to complete all of the dietary assessments during follow-up. One limitation of the study is that it included middle-aged women from a generally homogenous educational and socioeconomic background, and it's possible that results from this cohort of nurses may not be representative of outcomes for the general population, the authors note. Participants also were not asked specifically about consumption of gluten-free products or adherence to a gluten-free diet, making it possible that gluten intake may have been overestimated for some women in the study. However, there isn't evidence from previous research to suggest that avoiding gluten would prevent cognitive decline or that eating gluten would impair cognition, said Dr. Jonas Ludvigsson, a professor of clinical epidemiology at the Karolinska Institutet in Stockholm, Sweden, who wasn't involved in the study. "These findings were expected and comforting," Dr. Ludvigsson said by email. "Billions of people consume gluten on a daily or weekly basis so it would have been quite worrying if the authors had demonstrated a link to poor cognitive function." Clinicians advising patients on measures to improve cognitive health shouldn't focus on gluten, Dr. Ludvigsson advised. "I recommend that everyone take care to be physically active, stay mentally active, avoid smoking and alcohol, and regularly see family and friends for social contacts," Dr. Ludvigsson said. "These recommendations will go a long way." —Lisa Rapaport Source
