AP Medical WriterCHICAGO (AP) -- A study raises the provocative possibility that cholesterol-lowering drugs taken by millions of Americans can also ward off Alzheimer's disease.
The study found that high cholesterol levels appear to harm the brain and lead to mental decline and Alzheimer's disease. But it also found that older women who took drugs called statins -- sold under such brand names as Lipitor, Zocor and Mevacor -- had less mental impairment than non-users.
"Our results support the hypothesis that statins may prevent Alzheimer's disease," said Dr. Kristine Yaffe, chief of geriatric psychiatry at San Francisco Veterans Affairs Medical Center.
However, the study was not designed to test the drugs' effects on mental sharpness, and Yaffe said more work is needed to determine whether statins really can lower the risk of getting the degenerative brain disease that affects some 4 million Americans.
The study, published Thursday in the March issue of the Archives of Neurology, also was limited to data primarily from white women suffering from heart disease. Researchers said it is unclear whether the results would apply to nonwhite women or men, or anyone without heart disease.
While the study appears to support a link between cholesterol and Alzheimer's, it is not definitive, said Bill Thies, vice president of medical and scientific affairs at the Alzheimer's Association.
Previous research on cholesterol and Alzheimer's has been mixed.
High cholesterol can narrow the arteries and raise the risk of heart disease. Some researchers think the high cholesterol may also affect brain arteries and promote the clumping of a protein called beta-amyloid, which is thought to damage the brain in Alzheimer's.
Yaffe and her colleagues analyzed data on 1,037 postmenopausal women with an average age of 71 who participated in a study on the use of estrogen and progestin supplements.
The four-year study involved women with heart disease and tested the effects of hormone supplements on their hearts. It included data on cholesterol levels and statin use. The women were subjected to tests of their memory, attention and language.
None of the participants were taking Alzheimer's medication or had diagnosed dementia.
Women with the highest overall cholesterol readings -- 235 to 432 -- faced a 77 percent increased risk of having cognitive impairment, compared with those with lower levels.
A similar risk was found in women with the highest levels of the artery-clogging LDL, or bad cholesterol -- 145 to 347.
Among statin users, 37 women, or 6 percent, had cognitive impairment, compared with 42 -- 9 percent -- of nonusers.
Women whose total and LDL cholesterol levels declined during the four years -- through statin use or other means -- were about 50 percent less likely to have cognitive impairment than those whose levels increased.
------On the Net:
National Institute on Aging's Alzheimer's: http:// www.alzheimers.org