The evolution of the human menopause.

The females of most species die soon after ceasing to reproduce, their purpose in life being to ensure survival of their kin. Human females may live more than one-third of their lives after they cease to reproduce, a property shared by few species, one of which is Orca whales. Orcas have been extensively studied because families live together in stable units or pods and individual whales have distinctive markings, enabling them to be identified. The females survive long after the menopause, one possible reason for this being that the older females provide a survival advantage since they are seen to lead the pods more often than younger females or males, thus providing a survival advantage in times of food shortage. The female lifespan is increasing in most countries worldwide, principally due to decreased infection and maternal mortality. Women are now more active through middle and into older age. Whatever sort of life they wish to lead, women need to be as fit as possible to facilitate healthy aging. Chronic diseases that affect millions of women are cardiovascular disease, osteoporosis, cancer, and dementia. The incidence of all these is increased by obesity, the prevention of which is a major challenge in our society. Hormone therapy may have a place for some women but for many others taking control of their health by lifestyle intervention is a major contributor to disease prevention. It is our duty as doctors to encourage this at every opportunity to help all women live a fruitful and healthy old age.