Consuming Mediterranean Diet Reduces Alzheimer's Risk

Consuming a diet high in fruits and vegetables, nuts and fish—like the typical Mediterranean diet—appears to reduce the risk of developing Alzheimer’s disease, compared to individuals whose diets contain more high-fat dairy products and red meat, according to a study appearing in the Archives of Neurology (ePub 13 Apr 2010; 2010;67(6); DOI:10.1001/archneurol.2010.84). There is increasing evidence linking diet to risk of Alzheimer’s disease (AD), although the impact of specific food items or nutrients is difficult to determine given the synergistic effects of food combinations.

In this investigation, Yian Gu, Ph.D., Columbia University Medical Center, New York, and colleagues studied 2,148 older adults (age 65 and older) without dementia living in New York. Participants provided information about their diets and were assessed for the development of dementia every 1.5 years for an average of four years. Several dietary patterns were identified with varying levels of seven nutrients previously shown to be associated with Alzheimer’s disease risk: saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), omega-3 fatty acids, omega-6 fatty acids, vitamin E, vitamin B12 and folate.

During the follow-up, 253 individuals developed Alzheimer’s disease. One dietary pattern was significantly associated with a reduced risk of the disease. This pattern involved high intakes of salad dressing, nuts, fish, tomatoes, poultry, fruits and cruciferous and dark and green leafy vegetables, and low intakes of high-fat dairy, red meat, organ meat and butter.

The combination of nutrients in the low-risk dietary pattern reflects multiple pathways in the development of Alzheimer’s disease, the authors noted. “For example, vitamin B12 and folate are homocysteine-related vitamins that may have an impact on Alzheimer’s disease via their ability of reducing circulating homocysteine levels, vitamin E might prevent Alzheimer’s disease via its strong antioxidant effect and fatty acids may be related to dementia and cognitive function through atherosclerosis, thrombosis or inflammation via an effect on brain development and membrane functioning or via accumulation of beta-amyloid,” they wrote.

In their conclusion, the authors stated, “In conclusion, we identified a [dietary pattern] that was strongly protective against the development of AD. … Our findings provide support for further exploration of food combination–based dietary behavior for the prevention of this important public health problem.”
Sources:

* JAMA & Archives: Study Identifies Food Combination Associated With Reduced Alzheimer's Disease Risk