Diet and Dementia: What Foods Increase or Decrease Alzheimer’s Risk?

In the blue zones region of Ikaria, Greece, dementia among people over 85 is rare — over 75 percent less common than it is in the United States. (About half of Americans over 85 years old show signs of Alzheimer’s disease.)

Depression, cardiovascular disease, and type 2 diabetes are also rare. Ikarians eat a more austere form of what Americans call the Mediterranean diet, and what we call the plant-slant diet common to all blue zone areas: 95 percent of their calories come from plant foods and meat is eaten sparingly.

The NutritionFacts video below breaks down the science of why dementia is much lower among people who eat a Mediterranean-style diet. We also give a short summary of the video below.

Video Summary: There is considerable scientific evidence that healthy dietary patterns such as the Mediterranean diet are associated with lower Alzheimer’s risk and slower cognitive decline.

The Mediterranean diet* is high in vegetables, beans, fruit, and nuts, and low in meat and dairy. But what are the protective components in the diet? Looking at the research, the important dietary differences seem to be the high plant consumption and the lower fat consumption.

China has the lowest fat intake and lowest Alzheimer’s rates and the United States has the highest fat intake and highest Alzheimer’s rates. Looking closer, the type of fat does matter. Harvard researchers found that higher saturated fat intake was associated with a poorer trajectory of cognition and memory. Women with the highest saturated fat intake had 60 to 70 percent greater odds for the worst change on brain function.

Foods high in saturated fat: Beef, lamb, pork, butter, cheese, sausages. These are the foods to avoid.

*The Mediterranean Diet (MeDi) referenced in the studies is characterized by:

  1. High intake of vegetables, legumes, fruits, and cereals
  2. High intake of unsaturated fatty acids (mostly in the form of olive oil)
  3. Low intake of saturated fatty acids
  4. Moderately high intake of fish
  5. Low-to-moderate intake of dairy products (mostly cheese or yogurt)
  6. Low intake of meat and poultry
  7. Regular but moderate amount of ethanol, primarily in the form of wine and generally during meals.

Dr. Greger’s sources:
DE Barnes, K Yaffe.The projected effect of risk factor reduction on Alzheimer’s disease prevalence. Lancet Neurol. 2011 Sep;10(9):819-28.
I Lourida, M Soni, J Thompson-Coon, N Purandare, IA Lang, OC Ukoumunne, DJ Llewellyn.Mediterranean diet, cognitive function, and dementia: a systematic review. Epidemiology. 2013 Jul;24(4):479-89.
N Scarmeas, JA Luchsinger, R Mayeux, Y Stern. Mediterranean diet and Alzheimer disease mortality. Neurology. 2007 Sep 11;69(11):1084-93.
WB Grant. Dietary Links to Alzheimer’s Disease. Alzheimer’s Disease Review 2, 42-55, 1997.
OI Okereke, BA Rosner, DH Kim, JH Kang, NR Cook, JE Manson, JE Buring, WC Willett, F Grodstein. Dietary fat types and 4-year cognitive change in community-dwelling older women. Ann Neurol. 2012 Jul;72(1):124-34.
M Alarcón, E Fuentes, N Olate, S Navarrete, G Carrasco, I Palomo. Strawberry extract presents antiplatelet activity by inhibition of inflammatory mediator of atherosclerosis (sP-selectin, sCD40L, RANTES, and IL-1β) and thrombus formation. Platelets. 2014 Apr 21.
RO Roberts, YE Geda, JR Cerhan. Vegetables, unsaturated fats, moderate alcohol intake, and mild cognitive impairment. Dement Geriatr Cogn Disord. 2010;29(5):413-23.

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