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Isle study finds
brain boosters
Vitamins C and E may
By Lee Bowman
protect tissue and mental
abilities against the effects
of age, UH doctors say
Scripps Howard News ServiceTaking supplements of vitamins C and E may help preserve mental ability later in life and also could protect against dementia, according to a new report.
The long-term study, involving more than 3,300 Japanese-American men living in Hawaii, adds to the evidence that these anti-oxidant vitamins offer protection against damage from free radicals, the biochemical equivalent of rust, as our bodies age. The rogue oxygen particles have been implicated in heart disease, stroke, cancer, dementia, Alzheimer's disease and even wrinkled skin.
Doctors at the University of Hawaii had suspected that the vitamins offered sufficient protection from stroke and that the side benefit was less chance of dementia brought about by stroke.
"However, to our surprise, we found there was not a significant association between vitamin supplement use and clinically recognized stroke," said Dr. Kamal Masaki, lead author of the study published in the journal Neurology on Tuesday.
Instead, "we believe antioxidants like vitamin E and C may protect against vascular dementia by limiting the amount of brain damage that persists after stroke," Masaki said.
"The supplements may also play a role in protecting against brain cell and membrane injury involved in many aging-related diseases, thus resulting in significantly higher scores on mental performance tests in later life."
Rates of dementia and cognitive impairment increase exponentially after age 65, doubling every five to seven years until at least age 90. And vascular dementia, brought on by often mild strokes, is the second-most common form of impairment behind Alzheimer's. People suffering from vascular dementia face not only loss of mental function, but also physical impairments related to stroke, such as paralysis, and speech, language and visual disturbances.
Members of the study group were participants in the Honolulu Heart Program, a long-term study of heart disease and stroke started in 1965. The men, now aged 71 to 93, were interviewed about their diet, including vitamin use, in 1982 and 1988, and then assessed for dementia and mental ability during exams from 1991 to 1993.
Of the participants, 47 were diagnosed with Alzheimer's disease, 35 with vascular dementia, and 50 with other or mixed types of dementia; 254 had low cognitive test scores but were not diagnosed with dementia; and the remaining 2,999 men showed no mental decline.
The researchers found that participants taking both vitamin E and C supplements regularly (at least once a week) in any dose (more than just a multi-vitamin) were 88 percent less likely to have vascular dementia four years later, and 69 percent less likely to have mixed forms of dementia. But there was no significant reduction in the occurrence of Alzheimer's disease.
Previous reports have shown that vitamin E slows the progression of Alzheimer's disease, but research results have been mixed on whether antioxidants play much of a role in preventing the onset of the disease.
Those who were taking vitamins E and C in 1988 had a 20 percent greater chance of having better cognitive function during the follow-up exams than those who didn't.
But those taking supplements both in 1982 and 1988 had roughly a 75 percent greater chance of better mental performance, suggesting that long-term use could have a significant effect on keeping mental capability in late life.
"It is critically important for patients to practice preventive efforts shown both to lower stroke risk and to have broad-ranging beneficial effects," Masaki said.
But he cautioned that a specific prevention trial of both vitamins' effects at specific doses on both vascular dementia and Alzheimer's disease still needs to be done so that elderly people can gain the maximum benefit from taking the supplements.
UH John A. Burns School of Medicine
University of Hawaii
Ka Leo O Hawaii
