Postmenopausal Health and Disease from the Perspective of Evolutionary Medicine

Abstract

Anyone seeking to learn more about the subject of menopause 1 will find standard clinical and public health policy interpretations readily and prominently available. A simple Internet search for the word "menopause" returns numerous websites from reputable online medical resources 2 , all of which provide roughly the same, narrow definition: menopause is the complete cessation of menstruation, and occurs twelve months after the final menstrual period, usually between 45-55 years of age. Along with these definitions, much of the accompanying health information addresses symptoms, risk for associated diseases, and treatment options. This information fits the overall medical paradigm that menopause is not simply Epidemiological evidence indeed shows that the period surrounding and following menopause is associated with an increased prevalence of disease and disease risk factors, particularly those relating to the metabolic syndrome including weight gain, body composition change, obesity, hyperlipidemia, hypertension, and insulin resistance, all of which increase risk for heart attack, stroke, and type 2 diabetes (Torrens et al. 2009;Enns and Tiidus 2010). In the AbstractMenopause normally occurs between 45-55 years of age, marks the end of a woman's reproductive lifespan, and is accompanied by a reduction in estrogen that has substantial physiological effects. The standard medical view is that these changes underlie high postmenopausal disease rates, defining menopause as an estrogen deficiency condition needing treatment. This view stems from the idea that extended postmenopausal longevity is a consequence of recent technological developments, such that women now outlive their evolutionarily-programmed physiological functional lifespan. Increasingly, however, researchers employing an evolutionary medicine framework have used data from comparative demography, comparative biology, and human behavioral ecology to challenge the mainstream medical view. Instead, these data suggest that a two-decade human postmenopausal lifespan is an evolved, species-typical trait that distinguishes humans from other primates, and has deep roots in our evolutionary past. This view rejects the inevitability of high rates of postmenopausal disease and the concept of menopause as pathology. Rather, high postmenopausal disease risk likely stems from specific lifestyle differences between industrialized societies and foraging societies of the type that dominated human evolutionary history. Women in industrialized societies tend to have higher estrogen levels during premenopausal life, and experience a greater reduction in estrogen across menopause than do women living in foraging societies, with potentially important physiological consequences. The anthropological approach to understanding postmenopausal disease risk reframes the postmenopausal lifespan as an integral period in the human lifecycle, and offers alternative avenues for disease prevention by highlighting the importance of lifestyle effects on health.

Menopause Female Reproductive Senescence from the Viewpoint of Evolutionary Anthropology

“…The climacteric syndrome, however, can also be interpreted from the viewpoint of evolutionary medicine [81,82]. Evolutionary medicine was formalized in early 1990s, most notably by the evolutionary biologist George C. Williams and psychiatrist Randolph Nesse who tried to understand why natural selection has left the human body so vulnerable to diseases [83].…”