Smoking, estrogen bad combination for Alzheimer's.(Gynecology)

MIAMI BEACH -- The risk of Alzheimer's disease declines by almost half among postmenopausal nonsmokers who use estrogen therapy, but nearly doubles among those who both smoke and use estrogen therapy, Rosebud O. Roberts, M.B., said in a poster presented at the annual meeting of the American Academy of Neurology.

Dr. Roberts, an epidemiologist at the Mayo Clinic, Rochester, Minn., also found that early estrogen therapy might be a predictor for Alzheimer's in postmenopausal women; in contrast, estrogen therapy taken later in life appears to be more protective. But these conclusions may have more to do with premenopausal estrogen levels than postmenopausal estrogen therapy, she said in an interview.

"What I suspect is that smoking may lead to lower estrogen levels premenopausally, which could lead to brain neurons that are less viable and more likely to die early. Those who initiate therapy earlier probably have less [endogenous] estrogen, and more symptoms, while those who initiate therapy at a later age--because they had fewer symptoms or less severe symptoms--probably had more premenopausal estrogen."

She and her associates conducted a case-control study that included 216 women with natural menopause ...