Monday July 15, 2013 (Foodconsumer.org) -- Dr. Martha Clare Morris, ScD and colleagues published a study in Journal of American Medical Association (JAMA) suggesting that taking vitamin E supplements or eating vitamin E rich foods may help prevent Alzheimer's disease.

The study did not find any antioxidants have the same or similar protective against the development of Alzheimer's disease that affects an estimated 5 million American elderly people.

Oxidative stress has been suspected to be a cause for Alzheimer's disease and it is reasonable to speculate that antioxidants may have some protection against the disease.

The study tried to associate intake of antioxidants including vitamin E, vitamin C and beta carotene with incident Alzheimer's disease. Enrolled in the study were 815 men and women aged 65 years or older who were free of Alzheimer's disease at the baseline and followed up for a mean of 3.9 years.  Dietary information was collected through a food frequency questionnaire 1.7 years after baseline.  Diagnosis of Alzheimer's disease was based on the standard criteria.

The study found that after adjustment for age, education, gender, race and APOE ?4, and length of follow-up, participants in the highest quintile of vitamin E intake from foods were 70 percent less likely to be diagnosed with Alzheimer's disease. However, the protection was observed only in individuals without APOE ?4.

The protective association became less significant after adjustment for other dietary factors. Specifically, after adjustment for baseline memory score, the risk among those with high intake of vitamin E was reduced by 64%.

Nevertheless, intake of vitamin C, beta carotene, and vitamin E from supplements was not significantly correlated with risk of Alzheimer's disease.

the study concluded "vitamin E from food, but not other antioxidants, may be associated with a reduced risk of AD (Alzheimer's disease). Unexpectedly, this association was observed only among individuals without the APOE ?4 allele.

Another study led by Marianne J. Engelhart, MD, MSc and colleagues and also published in JAMA found both vitamin E and vitamin C render a protective effect against Alzheimer's disease.

The data used for the second study came from the Rotterdam Study, a population-based, prospective cohort study in the Netherlands.  Enrolled in the study were 5395 men and women aged 55 years or older at baseline in 1990 to 1993 who were free of dementia.  Participants were re-examined twice later for incident dementia.

The researchers found both vitamin C and vitamin E were associated with reduced risk of Alzheimer's disease.  The association was not affected by the education status and apolipoprotein E genotype. (rpeorting by Jimmy Downs)