Ovary removal before menopause could cause memory loss in women, Mayo Clinic study
Removal of ovary in women before menopause is likely give rise to the serious condition of memory disorder--dementia, says study conducted by Mayo Clinic researchers.
BY OUR PHARMA CORRESPONDENT
April 10, 2006
Usually, surgeons remove one or both ovaries to prevent cancer in still-fertile women, who have some event that leads to surgery to remove their uterus.
The study on 2,511 women had these operations between 1950 and 1987. The women were then matched with women who did not undergo ovary removal. The team determined whether the women developed dementia by interviewing a family member or by giving the women a test.
If the women remove two ovaries before age 46, they get a 70 percent increased risk of dementia. And those women who have only one ovary removed before age 38 -- this is a surgery more often done in younger women -- there is a 260 percent increase in dementia, the researchers noted at the annual meeting of the American Academy of Neurology in San Diego.
However, some experts believe that there are a lot of reasons to keep the ovaries in, ranging from heart health to vagina health. But there is just no indication that it makes a difference in dementia.
But rat studies by Johns Hopkins & the National Institute on Aging recently confirmed that removing the ovaries of middle-aged rats sped the animals' age-related loss of mental function. Estrogen replacement -- if done on the proper schedule -- prevented this effect.
Other researchers cite genetical reasons for cognitive decline in women with ovarian surgery. 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.
Another study found that women with Parkinson's disease tend to have defects in certain estrogen-related genes. It suggests that women who carry these unusual genes may be at higher risk of dementia -- and ovary removal simply magnifies this risk.
So it is always 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, they say.