The proportion of women living to 90 and beyond has been increasing in the US. A recent study found that women who reached natural menopause after age 50 had a much better chance of a longer life.
The Women’s Health Initiative:
The Women’s Health Initiative, a study funded by the National Institutes of Health, was begun in 1993. It was an exceptionally large study, including more than 160,000 healthy postmenopausal women between the ages of 50 and 79. The most famous finding from the Women’s Health Initiative was that hormone replacement therapy does not prevent heart attacks and strokes as was expected. That was a randomized, controlled trial, but the investigators have also learned a great deal just from collecting data on these women as they went about their normal lives.
Nonagenarians Had Later Menopause:
Research on 16,000 participants in the Women’s Health Initiative found that 55 percent of these women celebrated their 90th birthdays. Starting menstruation late, after age 12, was associated with longer life. So was a later age at menopause. The statisticians compared women reaching menopause between 50 and 54 or after 55 to those reaching menopause by age 40. Those with delayed menopause were about 19 percent more likely (relative risk) to make it to 90 years of age.
It may be that women who don’t smoke and manage to avoid heart disease and diabetes are more likely to go through menopause later. They are also more likely to achieve longer life. Women who had a reproductive span of 40 years or more also lived longer.