Eating lots of unsaturated, unhydrogenated fats may be protective against Alzheimer's disease (AD), whereas eating lots of saturated or hydrogenated fats may increase the risk of AD, according to an article in the February issue of The Archives of Neurology.
Previous studies have suggested that diets high in total fat, saturated fat, and dietary cholesterol may increase the risk of dementia, according to information given in the article.
Martha Clare Morris, Sc.D., of Rush-Presbyterian-St. Luke’s Medical Center, Chicago, and colleagues investigated the impact of different dietary fats on AD.
The researchers evaluated a random sample of 815 community residents aged 65 years and older who did not have AD at the beginning of the study and who completed questionnaires on their dietary habits an average of 2.3 years before the evaluations.
The researchers found that after an average follow-up of 3.9 years, 131 participants developed AD. Diets high in saturated fats and trans-unsaturated fats were positively associated with risk of AD, whereas intakes of polyunsaturated fat and monounsaturated fat were associated with a decreased risk of AD. People who consumed the most saturated fat had 2.3 times the risk of developing AD compared with participants who consumed the lowest amount of saturated fats.
The researchers write, "We found increased risk of incident Alzheimer's disease among persons with high intakes of saturated and trans-unsaturated fats and marginally significant decreased risk with high intakes of w-6 polyunsaturated and monounsaturated fats. Consumption of vegetable fat and a high ratio of polyunsaturated to saturated fats were also protective, whereas total fat, animal fat, and dietary cholesterol had no association with Alzheimer's disease."