Why do women live longer than men?

SIR – In most countries the life expectancy at birth of women is longer than that of men. In the past it was generally assumed that this is due to biological reasons. Is it? Or are men more reluctant to consult a doctor; and is their life-style less healthy, e.g. with regard to smoking and drinking? Are they more exposed to accidents? On the other hand, women are exposed to the dangers of child-birth – earlier this year a young relation of mine died of puerperal fever in Stockholm. Is less bing spent on male health problems like prostate cancer than on female health problems like breast cancer, relative to the incidence of such diseases? The 1997 Encyclopædia Britannica (‘Population’, 25: 1035) [1] states that the reasons for the difference in life expectancy between men and women are ‘not well understood’. That suggests that there is a need for research on this matter. The article also mentions that ‘this female advantage has grown as overall life expectancy has increased’. That means that it is more of a problem in the developed countries than in the developing ones, and more of a problem today than it was yesterday. Does this difference characterise other mammals too, in particular the primates? That would indicate whether we should continue to regard it as a natural phenomenon, or whether it is an anomaly which we should try to rectify. Should a just society strive to bring about gender equality in life expectancy? Using the figures from the latest United Nations Statistical Yearbook [2] I calculated, for a number of developing and developed countries, what I would call the ‘Gender Longevity Difference Index’ (GLDI), namely the life expectancy of women minus that of men, expressed as a percentage of the average life expectancy of the two sexes. The lower the index, the greater is gender equality in this respect. Of the developed countries, Greece did best, with a relatively low GLDI of 6.58 in spite of a high average life expectancy of 77.5 years. France did not do well, with a GLDI of 10.14. Russia did disastrously, with a GLDI of 17.59 – of the 3.5 million persons under the age of 60 who died in Russia over the last five years, a disproportionate number were men [3]. It is my hope that this letter might lead to debate, then research, and then action to close the gender longevity gap.