Written by Marcia J. Egles, MD. 2258 seniors without Alzheimer’s disease or dementia whose diets closely resembled the Mediterranean Diet were 40% less likely to develop Alzheimer’s disease.
Alzheimer’s disease, the most common form of dementia, is a devastating brain disease occurring in older adults. Ten percent of Americans over the age of 65 years are affected. By the age of 85, upwards of fifty per cent are affected. The disease is characterized by progressive memory loss, and the gradual destruction of all mental abilities, including language, judgment, reasoning, emotional control and the ability to care for oneself. In a very small number of cases, a genetic cause has been found. In general, the cause is unknown, although dietary influences are thought to play a role (1).
Rather than focusing on individual nutrients or one particular food group, the study, “Mediterranean diet and the risk for Alzheimer’s disease”(3), looked at the association of an overall diet on the risk of developing Alzheimer’s disease. The Mediterranean diet (3) consists of a high intake of vegetables, legumes, fruits, cereals, fish, and unsaturated fatty acids (olive oil), but a low intake of saturated fatty acids, meat and poultry, and a low-to-moderate consumption of dairy products. Also, a regular but moderate amount of wine is consumed, usually during meals.
The study recruited senior citizens (Medicare beneficiaries), residing in an ethnically diverse area of Manhattan. They underwent extensive neurological and general health testing by physicians. A total of 2,258 seniors without evidence of Alzheimer’s disease or any form of early dementia qualified for the study. Their diets over the past year were assessed by interview using a 61-item food frequency questionnaire (4).
They were evaluated for dementia every 1.5 years for the next 4 years on average. Those whose diets most closely resembled that of a Mediterranean diet were found to have a 40% lower rate of development of Alzheimer’s disease compared to those whose diets least resembled it. This association remained significant when adjusted for factors such as gender, smoking, age, or ethnicity. The levels of individual nutrients or supplements were not reported (3).
The Mediterranean diet has received favorable attention in recent years because of its associations with a lower risk of heart disease, several forms of cancer, and overall mortality (3, 5). This study supports the idea that a diet with plenty of vegetables, fruit, and fish might help prevent dementia.
Source: Scarmeas, Nikolaos, Yaakov Stern, Ming‐Xin Tang, Richard Mayeux, and Jose A. Luchsinger. “Mediterranean diet and risk for Alzheimer’s disease.” Annals of neurology 59, no. 6 (2006): 912-921.
© 2006 American Neurological Association
Posted August 27, 2008.
References:
- Alzheimer’s Disease. On-line guide by the Alzheimer’s Association.
- Scarmeas, Nikolaos MD et al. Mediterranean diet and risk for Alzheimer’s disease. Annals of Neurology, published on-line April 18,2006.
- Trichopoulou A, et al. Adherence to a Mediterranean diet and survival in a Greek population. New England Journal of Medicine 2003;348:2599-2608.
- Willett WC, et al. Reproducibility and validity of a semi-quantitative food frequency questionnaire. Am J Epidemiology 1985: 122:51-65.
- Singh RB et al. Effect of an Indo-Mediterranean diet on progression of coronary artery disease in high risk patients. Lancet 2002;360:1455-1461.
