Dementia Risk Linked to Ovary Removal
Dementia More Common in Women Who Lose Ovaries in Their 30s and 40s
Opposing Views continued...
"I was surprised to see that there was so much similarity between Dr. Rocca's epidemiology study and our basic-science study in rats," Savonenko tells WebMD. "Our rats were absolutely doing the same thing as these women."
Still, Savonenko would be cautious in advising women not to undergo doctor-recommended ovary removal.
"I think there are very dramatic reasons why women undergo this surgery," she says. "I don't think the possible side effects on [mental function] should hold women from necessary ovary removal. But what I would suggest is consideration of estrogen replacement therapy for this cohort of women, particularly since there now is this evidence of cognitive decline."
One reason Norris is skeptical of the Rocca study is that removal of one ovary had a much larger effect than removing both ovaries.
"Why are women with one ovary taken out doing worse than those with both taken out? You have to raise an eyebrow about that," he says.
Rocca suggests that the situation is more complicated than most researchers realize. He suggests that women who have the kinds of problems that result in hysterectomy -- such as uterine fibroids or endometriosis -- have some underlying defect in the way their bodies use estrogen.
In another study he presented at the AAN meeting, Rocca found that women with Parkinson's disease tend to have defects in certain estrogen-related genes. He suggests that women who carry these unusual genes may be at higher risk of dementia -- and ovary removal simply magnifies this risk.
"So the game is more complex than just the issue of how much estrogen a woman's ovaries are making," Rocca says. "We will at some point be better able to advise the woman facing the surgeon and predict final balance between the benefit of preventing ovarian and breast cancer vs. the risk of dementia, Parkinson's disease, stroke, or heart attack. It is very complicated -- but if what we are seeing gets confirmed by others, in the future we could offer to the individual woman a more intelligent and informed basis to make a decision on ovary removal."