How Diet May Impact Alzeimer's Disease

From IDEA - The Health and Fitness Association, September 15, 2015 It’s never too early to talk about Alzheimer’s disease. With new research suggesting that modifiable lifestyle factors could be responsible for 20%-40% of Alzheimer’s disease risk, primary prevention through sound nutrition is a hot topic.  In fact, there is evidence that Alzheimer’s may start in the brain 20-30 years before symptoms appear. Dietary Patterns Certain dietary patterns appear to protect against cognitive decline. Historically, the Mediterranean diet and the Dietary Approaches to Stop Hypertension (DASH) diet have been widely studied for heart disease prevention, but more recent research has also focused on their ability to decrease dementia risk. In a prospective study in the American Journal of Clinical Nutrition, both diets were associated with a decrease in cognitive decline over an 11-year period. Higher adherence to the Mediterranean diet has also been associated with lower levels of inflammatory markers and therefore may decrease oxidative stress in the brain. Consider also results of a prospective study evaluating a new dietary pattern developed to focus on brain health. After reviewing comprehensive evidence, Martha Clare Morris, ScD, of Rush University created the Mediterranean-DASH Intervention for Neurodegenerative Delay—also known as the MIND diet—which uses a three-pronged approach:

  • emphasizing plant-based, whole foods, and olive oil as the primary oil
  • limiting animal products and saturated fat
  • promoting one fish meal a week because of the strong link between omega-3 and brain health

Morris followed 923 people, aged 58–98, over 4.5 years to see who would develop dementia, and then she compared how closely they followed the MIND, Mediterranean or DASH diets based on scales of adherence. The MIND diet was associated with a 53% risk reduction for those with the strictest diet adherence and a 35% reduced risk for those with moderate diet adherence. The DASH and Mediterranean diets elicited significant reductions in cognitive decline only with the highest level of adherence. This is a notable difference: Always adhering strictly to a new way of eating isn’t easy, so it’s good news to see that moderate adherence to the MIND diet might be protective.

The MIND diet’s specific recommendations may explain its effectiveness. As Morris notes, animal research suggests that leafy greens and berries, in particular, are protective of the aging brain, and therefore the MIND diet recommends at least two servings of flavonoid-rich berries and a minimum of six servings of vitamin-rich leafy greens per week. The DASH and Mediterranean diets, however, recommend eating a lot of nonspecific vegetables and fruit, which are still beneficial but may not be as imperative for brain health. According to Morris, evidence from the MIND study shows that those who ate the most leafy greens were 11 years younger in cognitive age than those who ate the least. Clients would benefit from including kale, mustard greens, romaine lettuce, spinach and other leafy greens on their weekly menus. As experts continue to work hard to discover new evidence about Alzheimer’s, we should inform our clients about current research while keeping in mind that our understanding of primary prevention is evolving. We don’t yet have all the answers, but following a MIND, Mediterranean or DASH-type dietary pattern that emphasizes berries, leafy greens, and vitamin- and mineral-rich whole foods, shouldn’t be a brain buster.