There is no shortage of theories when it comes to why women tend to live longer than men. There is little consensus on the mechanisms at a detail level, however. Looking out across species other than our own doesn't help all that much, as even when only considering mammals one sees a variety of outcomes. There are enough species in which females live longer than males to be uncomfortable with hypotheses involving culture and lifestyle choices in humans, and enough species in which females do not live longer than males to undermine and complicate most of the potential biochemical and evolutionary explanations.
It has become increasingly evident that males and females across species show differences in lifespan and ageing. In many mammals, females live longer than males, while in birds, males are the longer-lived sex. In humans, women live on average 5 years longer than men. Paradoxically, women are frailer later in life (usually after the onset of menopause) and do not necessarily have a longer healthspan.
Age-associated illnesses are often sex-biased. For example, in 2018, men older than 65 years showed higher death rates of cancer, heart disease, stroke, and diabetes, while Alzheimer's disease (AD), influenza, and pneumonia showed higher death rates in women. Women are also more susceptible to autoimmunity. Such age-associated sex biases deserve more attention, as the elderly population worldwide is expected to double from 12% to 22% between 2015 and 2050.
One reason why either sex can be more prone to certain age-associated phenotypes are the sex chromosomes. In mammals, females are XX and males XY, where the presence of the Y chromosome triggers the development of male gonads and secondary sexual traits. Mammals share evolutionarily conserved sex chromosomes, but in wild populations, not all mammalian females live longer than males. However, when they do, they have a longer median lifespan of around 20%. How the sex chromosome complement impacts longevity is an active area of research.
Link: https://doi.org/10.1098/rsob.240177
View the full article at FightAging
