Pregnancy And Alzheimer’s
The more full-term pregnancies a woman has, the greater her risk of developing Alzheimer’s disease late in life. The most recent research on this connection found that women who have had five or more children are 70 percent more likely to develop Alzheimer’s than women who have had fewer children. The study also showed that women who had an incomplete pregnancy as a result of miscarriage or abortion were less likely to develop Alzheimer’s. Researchers from Korea’s Seoul National University College of Medicine reached these conclusions after studying 3,549 women in Korea and Greece whose average age was 71 (the investigation excluded those who were taking hormone replacement therapy and those who had had a hysterectomy or removal of their ovaries). The study team reported that of the 716 women in the study who had five or more children 59 developed Alzheimer’s compared to 53 of 2,751 women who had fewer children. In 2006 Italian researchers also found that a higher number of pregnancies was related to an increased risk of Alzheimer’s. Hormonal changes related to multiple pregnancies might be responsible for the added risk, but this remains to be explored by further studies. If hormones prove to be involved, the new findings could lead to development of hormone-based preventive strategies, suggested study leader Ki Woong Kim, M.D., Ph.D.
My take? We know that two out of three Alzheimer’s patients in the U.S. are women, but we don’t know why. Researchers have been trying to determine whether women’s higher risk could be due to decreased levels of estrogen and progesterone after menopause. This new study raises questions about the influence of high levels of female hormones earlier in life. However, two other studies from U.S. researchers, neither of which has yet been published, came to the opposite conclusion – that the more children a woman has and the longer her reproductive life, the lower her risk of dementia. Although these results have been made public, you should be aware that the findings from unpublished studies are regarded as preliminary until published in a peer-reviewed journal. Clearly, we need more research to sort out these contradictory findings.
Alzheimer’s Association, “Pregnancy and reproductive history may impact dementia risk.” Presentation at International Alzheimer’s Association Conference, July 23, 2018.
Ki Woong Kim et al, “Differential effects of completed and incomplete pregnancies on the risk of Alzheimer disease.” Neurology, July 18, 2018, doi.org/10.1212/WNL.0000000000006000
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