The type of fat that people consume in their diets can either protect them against Alzheimer's disease or increase their risk of getting it, according to a study in the February issue of Archives of Neurology.

Few studies have investigated the effects of dietary fats on the development of Alzheimer's disease. In this study, researchers found that unsaturated, unhydrogenated fats have a protective effect against Alzhiemer's disease, while saturated or hydrogenated fats may increase people's risk of getting the disease.

The study involved 815 people aged 65 years and older who did not have Alzheimer's disease from the beginning and who completed a food-frequency questionnaire.

The participants were followed for an average of 3.9 years. During that time, 131 developed Alzheimer disease. People whose saturated-fat intake was in the upper 20 percent had 2.2 times the risk of developing Alzheimer's disease compared with persons in the lowest 20 percent. An increased risk of Alzheimer's was also found in all but the lowest consumers of trans-unsaturated fats.

Since this area of research is new, researcher Martha Clare Morris said it is impossible to make any recommendations concerning the prevention of Alzheimer's based on this single study.

"What is nice about the findings, however, is that the same dietary fat profile we observed was associated with less risk of Alzheimer's disease is the same fat profile observed for reduction of heart disease, a very well researched area," Morris told Medical Week.

Morris, an assistant professor at Rush Institute for Healthy Aging in Chicago, said vegetable oils are high in the good types of fat as are nuts and seeds, peanut butter and avocados.

One way to think about high intake of the good fats, according to Morris, is to try and consume this type of fat at every meal.

A prototypical daily menu of good fats, according to Morris, would include:

--peanut butter toast for breakfast or an egg fried in vegetable oil (corn, safflower or olive);
--salad for lunch with oil-based dressing and sunflower seeds sprinkled on top or a sandwich or salad with regular mayonnaise;
--dinner of stir fry (vegetables, chicken and/or seafood) using vegetable oil or a slice of bread with margarine that does not have trans fat.

"One should of course not consume so much that the total number of calories is making you put on weight," Morris added.

Other sources: Archives of Neurology 2003;60:194-200