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Vitamins E and C may
reduce effects of Alzheimer's disease
Jan. 22, 2004 -
Antioxidant
vitamin supplements, particularly vitamins E and C, may protect the
aging brain from Alzheimer's disease, according to a study conducted by
the Johns Hopkins Bloomberg School of Public Health and other
institutions.
"These results are extremely
exciting. Our study suggests that the regular use of vitamin E in
nutritional supplement doses, especially in combination with vitamin C,
may reduce the risk of developing Alzheimer's disease," said Peter P.
Zandi, PhD, lead author of the study and an assistant professor in the
School's Department of Mental Health.
The researchers believe antioxidant
vitamin supplements may be an ideal prevention strategy for our aging
population as they are relatively nontoxic and are thought to have
wide-ranging health benefits. The study, "Reduced Risk of Alzheimer's
Disease in Users of Antioxidant Vitamin Supplements" is published in the
January 2004, issue of the journal Archives of Neurology.
The researchers examined data from the
Cache County Study, which is a large, population-based investigation of
the prevalence and incidence of Alzheimer's disease and other dementias.
Residents who were 65 or older were assessed from 1996-1997 and again
from 1998-2000. Study participants were asked at their first contact
about vitamin usage. The researchers then compared the subsequent risk
of developing Alzheimer's disease over the study interval among
supplement users versus nonusers to come to their conclusions.
Approximately 17 percent of the study
participants reported taking vitamin E or C supplements. These
individuals were significantly more likely to be female, younger, better
educated and reported better general health when compared to
non-supplement users. In addition to those who took vitamin supplements,
another 20 percent of study participants used multivitamins, but without
a high dosage of vitamin E or C.
The researchers found a trend towards
reduced Alzheimer's disease with a combination of vitamin E and C
supplements, even after controlling for age, sex, education and general
health. However, there was no notable reduction in the risk of
Alzheimer's disease with vitamin E or vitamin C alone or with
multivitamins. Multivitamins typically contain the recommended daily
allowance of vitamin E (22 IU or 15 mg) and vitamin C (75-90 mg), while
individual supplements contain doses up to 1,000 IU of vitamin E and
500-1,000 mg or more of vitamin C.
The researchers explained that the use
of vitamins E and C may offer protection against Alzheimer's disease
when taken together in the higher doses available in individual
supplements. In addition, there may be some protective effect with
vitamin E when it is combined with the lower doses of vitamin C found in
multivitamins.
Dr. Zandi said, "Further study with
randomized prevention trials is needed before drawing firm conclusions
about the protective effects of these antioxidants. Such trials should
consider testing a regimen of vitamin E and C in combination. If
effective, the use of these antioxidant vitamins may offer an attractive
strategy for the prevention of Alzheimer's disease."
The study was funded by grants from the
National Institutes of Health and National Institute of Mental Health.
The Bryan Alzheimer's Disease Center at Duke University completed the
APOE genotyping.
James C. Anthony, Ara S. Khachaturian,
Stephanie V. Stone, Deborah Gustafson, JoAnn T. Tschanz, Maria C. Norton
and John C. S. Breitner co-authored the study.
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