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INDIANAPOLIS, INDIANA. Oxidative stress is a major cause of accelerated aging and
has been clearly implicated in both Alzheimer's and Parkinson's disease. Antioxidants
such as vitamin C and E and the carotenoids have been shown to effectively combat
oxidative stress. A team of researchers from Indiana University now report that oxidative
stress may also be involved in memory loss and that older people with high vitamin E
levels are less likely to suffer from memory loss than are people with low levels. Their
study involved 4809 older people (aged 60 years and over) and was part of the Third
National Health and Nutrition Examination Survey (NHANES III) carried out between 1988
and 1994. All participants were given a test aimed at detecting memory loss (delayed
word recall and delayed story recall) and also provided blood samples for analysis of
vitamins A, C and E, selenium, carotenoids, folate, calcium, iron, and cholesterol. Overall,
7 per cent of the participants were found to have poor memory. Non-Hispanic blacks had
the highest prevalence of poor memory while non-Hispanic whites had the lowest. Higher
age, lower level of education, low family income (less than $20,000/year) and not enough
to eat were all associated with a higher incidence of memory loss. Blood serum levels of
selenium, vitamin A and vitamin C, and carotenoids (per unit of cholesterol) were not
associated with poor memory. There was, however, a clear correlation between vitamin E
level (per unit of cholesterol) and memory loss. Participants with vitamin E levels below
4.8 had a 175 per cent higher incidence of memory loss than did participants with a level
above 7.2. It is worth noting that high vitamin E levels were most prevalent among non-
Hispanic whites and among those taking vitamin supplements. Nevertheless, even after
adjusting for all other pertinent risk factors it was clear that people with a high vitamin E
level were significantly less likely to suffer from memory loss.
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