Researchers have suspected for years that the cocoa in chocolate could have health benefits, particularly because of chemicals that it can contain called flavanols. A recent clinical trial published in Nature Neuroscience suggests that those benefits might extend to the aging brain, although only to a limited extent.
In this new trial, healthy adults between 50 and 69 years of age agreed to be randomized to consume either a lot of cocoa flavanols or very little for three months. Researchers then measured blood flow in specific areas of the brain and tested the participants on two cognitive tasks. These cognitive tasks were chosen because scientists believe each is dependent on a specific area of the brain's hippocampus.
The first cognitive task activates the dentate gyrus of the hippocampus, an area that is vulnerable to aging. After three months of treatment, the adults with high flavanol intake performed substantially better on this task, suggesting that the cocoa flavanols had improved an aspect of cognitive impairment that commonly occurs with aging. The second cognitive task activates the entorhinal cortex, a brain area next to the hippocampus that is the first to show signs of damage from Alzheimer's disease. After three months of treatment, this task was unaffected by the high flavanol intake, suggesting that high flavanol intake had no effect on the area of the brain most susceptible to early Alzheimer's disease.
Based on this small trial, it is possible that high-flavanol cocoa can help to treat one aspect of aging-related cognitive impairment but will not protect against Alzheimer's. If you're considering giving high-flavanol cocoa a try, bear in mind that flavanol levels in chocolate and cocoa vary extensively. Milk chocolate general has fewer flavanols than dark chocolate and dutch-processing reduces flavanol levels, too.
Other clinical trials testing the benefits of cocoa and flavanols have conflicting findings.
Dr. Penny Dacks was previously the Director of Aging and Alzheimer’s Disease Prevention at the Alzheimer's Drug Discovery Foundation. She was trained in neuroscience at the Mount Sinai School of Medicine, the University of Arizona, and Queen's University (Canada) with individual fellowships from the National Institute of Health, the Evelyn F. McKnight Brain Research Foundation, the ARCS Foundation and the Hilda and Preston Davis Foundation. She has authored over 18 peer-reviewed scientific articles and is a member of the Society for Neuroscience, the Gerontological Society of America, the Endocrine Society and the Association for Women in Science.
Get the latest brain health news:
Celebrating National Chocolate Day