Do walnuts offer protection from Alzheimer's? A recent study in the Journal of Alzheimer's Disease reported that daily consumption of walnuts helped to protect mice against behavioral and learning impairments common in animals that exhibit features of Alzheimer's disease.
While laboratory mice can help scientists to determine whether a given food or drug is likely to affect specific molecules and disease pathways in humans (e.g., the beta-amyloid and tau characteristic of Alzheimer's disease), the authors of this study did not report on this effect. Instead, they evaluated protection from behavioral and learning impairments—results for which mice have not proven to be very reliable models.
Still, walnuts are a nutritious and minimally processed food full of vitamins, minerals, anti-oxidants, and flavonoids known to offer health benefits. They also contain omega-3 fatty acids, though not the long-chain omega-3 fatty acids that have been most directly linked to brain health.
Nuts in general are often a healthy choice, particularly for long-term health. They can be a part of a Mediterranean diet, which is linked to healthy aging and was reported to improve many aspects of health in older people in the 5-year PREDIMED clinical trial that compared the Mediterranean diet to a control low-fat diet. People who eat nuts may also be at a lower risk of dying from a variety of causes. In 2013, the New England Journal of Medicine reported that, among over 100,000 men and women from two observational studies, people who ate nuts had a lower risk of dying from most of major causes of death, at least over the course of the study duration. We can’t be sure if the nuts themselves were responsible for these health benefits; in both studies, people who ate nuts were also engaging in a variety of other potentially protective behaviors.
The bottom line: nuts are probably a great addition to a healthy, balanced diet. But here's little reason to conclude that walnuts or other nuts specifically protect against cognitive decline, Alzheimer's disease, or related dementias.
Photo: Pauline Mak
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.
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