Can Nutrition Reduce Alzheimer’s Disease Risk?

For decades, researchers and medical professionals concluded that the etiological underpinnings of Alzheimer’s disease were wholly genetic. Given this consensus, lifestyle medicine to prevent Alzheimer’s disease was neither widely researched nor advocated.

In the past decade, new data elucidates that lifestyle medicine can play a significant role in decreasing the risk of Alzheimer’s disease. Among the most prevalent and universal lifestyle factors contributing to Alzheimer’s disease risk and etiology is nutrition. A 2019 JAMA manuscript entitled “What is Dementia?” states that “Other recommendations for good brain health include keeping mentally, physically, and socially active, eating nutritionally-balanced meals and drinking alcohol only in moderation (not more than one alcoholic drink a day), and getting enough high-quality sleep.“ However, very few patients have an understanding of what constitutes “nutritionallybalanced meals.”

In 2015, nutritional epidemiologist Martha Clare Morris and her research team published the results of the nine-year Mediterranean-Dietary Approach to Systolic Hypertension (DASH) diet intervention for neurodegenerative delay, commonly referred to as The MIND Diet. This prospective study, funded by NIH’s National Institute of Aging, showed strong correlations between the consumption of specific foods and beverages and neurodegenerative delay. Those foods are dark leafy greens, colorful vegetables, whole grains, nuts, beans, poultry, berries, fish, and extra virgin olive oil.

While these may appear to be familiar constituents of a generally healthy diet, the MIND diet enumerates the frequency with which the aforementioned foods should be included in one’s diet in order to reduce the risk of Alzheimer’s disease. The basis of these frequencies is (1) data on subjects’ vitals that the researchers began collecting in 1997, (2) responses on an annual Harvard semiquantitative food frequency questionnaire which began in 2004, (3) the study subjects’ performance on nine annual clinical evaluations (involving a battery of cognitive tests), (4) statistical control of confounding variables, (5) and extensive review of validated studies related to diet and brain function. All subjects also provided consent for a brain autopsy upon death.

The resulting MIND Diet prescribes the following foods and food frequencies:

• 1/2 cup cooked or 1 cup raw Dark Leafy Greens per day • ½ cup cooked or 1 cup raw Colorful Vegetables per day • 1 ½ cups cooked Whole Grains per day • 1 oz. Nuts 5 days per week • ½ cup cooked Beans 3 days per week • 3 oz. cooked Poultry 2 days per week • 1 cup Berries 2 days per week • 3 oz. cooked Fish per week • Extra Virgin Olive Oil as the primary oil used • 1 (optional/maximum) 5 oz. glass of Wine per day

In addition to denoting foods to include on a daily and weekly basis, the MIND Diet details foods to limit or exclude from the diet to reduce the risk of Alzheimer’s disease. The foods to minimize or exclude are red meats, butter and stick margarine, cheese, pastries and other processed sweets, fast food, and fried foods. Given how ubiquitous these “brain unhealthy foods” are in our society, the MIND diet explicates the number of servings per week of these foods that the healthiest cohort included in their diets rather than oversimplifying the results to reflect complete abstinence of these foods in the subjects’ diets.

Given that people eat in the real world, it is unrealistic to expect that our patients will strictly adhere to any one dietary prescription or program. The results of the MIND diet study showed promising results for these “real world” eaters. The Mediterranean diet reduces the risk of Alzheimer’s disease if followed strictly. The DASH diet has also been shown to reduce the risk of Alzheimer’s disease with strict adherence. However, neither the Mediterranean nor the DASH diet has been shown to substantially decrease the risk of Alzheimer’s disease if followed loosely. Conversely, the MIND diet reduces the risk of Alzheimer’s disease by up to 53% if followed steadfastly. What’s encouraging is that even those who follow the MIND Diet loosely can reduce their risk of Alzheimer’s disease by up to 35%. In follow up studies, Dhana et al found that the strong correlations between MIND diet adherence and reduced risk of Alzheimer’s disease persisted even for subjects who were carriers of the APOE e4 allele.

As scientific advances in Alzheimer’s disease research occur, it is important for us to remember that while we cannot control our own or our patients’ genetic profiles, we can confidently implement and share that what we eat has a profound impact on our brain health. In addition to the many other tools in our clinical toolkits, may we all use food as medicine and our forks as our shields.

1. Arvanitakis, Zoe, and David A Bennett. “What Is Dementia?.” JAMA vol. 322,17 (2019): 1728. doi:10.1001/ jama.2019.11653 2. Morris, Martha Clare et al. “MIND diet slows cognitive decline with aging.” Alzheimer’s & dementia : the journal of the Alzheimer’s Association vol. 11,9 (2015): 1015-22. doi:10.1016/j. jalz.2015.04.011 3. van den Brink, Annelien C et al. “The Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and MediterraneanDASH Intervention for Neurodegenerative Delay (MIND) Diets Are Associated with Less Cognitive Decline and a Lower Risk of Alzheimer’s Disease-A Review.” Advances in nutrition (Bethesda, Md.) vol. 10,6 (2019): 1040-1065. doi:10.1093/advances/nmz054 4. https://www.rush.edu/news/new-mind-diet-may-significantlyprotect-against-alzheimers-disease 5. Dhana, Klodian et al. “Healthy lifestyle and the risk of Alzheimer dementia: Findings from 2 longitudinal studies.” Neurology vol. 95,4 (2020): e374-e383. doi:10.1212/WNL.0000000000009816