THURSDAY, April 6, 2006 (HealthDay News) -- New research suggests that removal of the ovaries significantly increases a woman's risk for cognitive problems later in life.
The lead author of a study released this week said the findings shouldn't prevent women from having their ovaries removed when they are diseased. However, Dr. Walter Rocca, a professor of neurology and epidemiology at Mayo Clinic, did advise that women be cautious, especially when they undergo the procedure to prevent a disease that hasn't appeared yet.
He added that, because estrogen might be at the root of the problem, estrogen-replacement therapy might help women who do undergo ovary removal avoid cognitive problems.
"The woman should discuss all of the pros and cons," Rocca said. "Our data will enrich these discussions by providing some other pieces of the puzzle."
According to Rocca, researchers have long suspected that estrogen -- which is found in both men and women -- protects the brain. But while studies have suggested an ovary-brain link in animals, there's been little research done in humans, he said.
So, Rocca's team decided to focus on women who no longer had a major source of estrogen -- their ovaries. An estimated 300,000 women undergo ovary-removal surgery (called oophorectomy or ovariectomy) each year, some because they have cancer and others because they fear cancer or some other illness.
In the study, the researchers examined the medical records of 1,209 women who had both ovaries removed and 1,302 women who had only one removed from 1950 to 1987 in Olmsted County, Minn., home of the city of Rochester and the Mayo Clinic. The women's cognitive abilities were also tested.
The researchers released the findings Wednesday at the American Academy of Neurology annual meeting, in San Diego.
The women who'd undergone ovariectomies -- removal of the ovaries -- were 1.2-1.6 times more likely to suffer from dementia, researchers found. As women age, a third will develop dementia, and the increased risk significantly boosts their likelihood of having cognitive difficulties, Rocca said.
The research suggests the risk is higher when the surgery takes place at a younger age -- removal of both ovaries before age 46 or removal of one ovary before age 38.
It's not entirely clear how ovarian function might be connected to brain health, but estrogen production seems a likely suspect. However, Rocca said, "we cannot be sure whether it's the estrogen itself that's involved, or rather that women who have the surgery may be already genetically predisposed to having estrogen-related problems."
The study highlights the ongoing debate over hormone replacement therapy.
"Old-time gynecologists said estrogen is just as good coming out of a bottle as out of the ovaries," said Dr. Richard Paulson, a professor of reproductive medicine at the University of Southern California. But recent research linking long-term HRT to breast cancer and other illnesses has called that assumption into question, he noted.
What to do? "The message is: Don't have your ovaries taken out willy-nilly, think about it a lot," Paulson said. "If you feel comfortable taking estrogen during menopause, maybe it would be OK. But if you're not comfortable taking estrogen, this is another piece of data suggesting those ovaries shouldn't come out."
More information:
Learn more about ovary removal from the Mayo Clinic.
