28 February 2003
A high intake of vegetable fats and unsaturated fats appears to protect against Alzheimer's disease, but supplemental vitamins appear to have no protective effect, 2 US studies show.
The first study followed more than 800 elderly people without Alzheimer's for 4 years.
The study found that the people who ate the most vegetable fats were 80 per cent less likely to develop Alzheimer's than those who ate the least vegetable fat (Archives of Neurology 2003; 60: 194-200).
People with a high intake of omega-6 polyunsaturated fat and mono-unsaturated fat, and who had a high ratio of polyunsaturated fat to saturated fat, were 70 to 80 per cent less likely to develop Alzheimer's than people with lower intakes of these fats.
But the patients who ate the most saturated fats and trans-unsaturated fats — which occur when vegetable oils are partially hydrogenated in the production of commercially baked products and margarine (to make it spreadable) — were approximately twice as likely as people eating less saturated fat to develop Alzheimer's.
Intake of total fat, animal fat and dietary cholesterol was not associated with Alzheimer's, and adjusting for beta carotene, vitamin C or vitamin E intake, smoking, alcohol and use of statins (blood cholesterol lowering medications) did not affect the results.
The mechanism for the link between dietary fat composition and Alzheimer's was not known, the researchers said.
The second study followed 980 elderly people without Alzheimer's for 4 years.
This study showed that supplemental, dietary, or total intake of beta carotene, vitamin C or vitamin E was not linked to developing the condition (Archives of Neurology 2003; 60: 203-08).
Age, level of education, sex, race and smoking did not affect the results.
Last Reviewed: 02 March 2003