ROTTERDAM, THE NETHERLANDS. There is increasing evidence that oxidative stress plays an important role in the initiation and progression of Alzheimer's disease. Dutch researchers have just released the results of a major study aimed at determining if dietary antioxidants such as vitamin C, vitamin E, beta- carotene, and flavonoids can help prevent Alzheimer's disease by reducing oxidative stress. The study involved 5395 men and women aged 55 years or older who were free of dementia at the beginning of the study in 1990-1993. During six years of follow-up 197 participants developed dementia of which 146 cases were diagnosed as Alzheimer's disease. After adjusting for age, sex, alcohol intake, education, smoking status, body mass index, total energy intake, and mental examination score at baseline the researchers concluded that a high intake of vitamin C and vitamin E was associated with a lower risk of Alzheimer's disease. The protective effect of antioxidants was particularly high among current smokers. Overall, participants whose daily vitamin C intake was greater than 133 mg/day had a 34 per cent lower incidence of Alzheimer's disease than did those with an intake below 95 mg/day. Participants whose vitamin E intake was above 15.5 mg/day had a 43 per cent lower incidence than those with an intake below 10.5 mg/day.
Engelhart, Marianne J. Dietary intake of antioxidants and risk of Alzheimer disease. Journal of the American Medical Association, Vol. 287, June 26, 2002, pp. 3223-29