Health survival paradox

The male-female health-survival paradox, also known as the morbidity-mortality paradox or gender paradox, is the phenomenon in which women experience more medical conditions and disability during their lives, but they unexpectedly live longer than men. It is considered a paradox because of the normal assumption that sicker people will die sooner than people who experience less disease and disability. In this case, however, the group of people that experiences the most disease and disability is the one that lives the longest.

Records of the female survival advantage can be traced back to the 18th century, but gained popularity and caught the eyes of researchers in the 19th century.

Female survival advantage

Women outlive men for all age groups and every year for which reliable records exist. This paradox has not been found in older adults, where women statistically have lower mortality rates than men, but they experience a similar rate of illness, as men.

A female survival advantage is found in some, but not all species. Various explanations for this have been proposed. But none are strongly supported. Most species studied show conditional sex differences in life span, for males or females depending on the species in question. In Humans, women outlive men in 176 of 178 countries for which records are available, both at age 5 and at age 50.

In 1950, in Scandinavia, the mortality rate for men aged 14-24 was twice as much as it was for women. The greatest increase in the female survival advantage from the period of 1950-2004 was among the 25-84 age group.

The female survival advantage holds true among humans, but the same can not be said for baboons.

Influential factors

Risky behaviors

Despite men suffering more fatal conditions, women have more non-fatal acute and chronic conditions. Young men in Latin America and the Caribbean have higher mortality rates due to homicide and traffic accidents. Some observers attribute this to attempts to live up to narrow ideas of what it means to be men increasing risky behaviors among young men. A study comparing the female survival advantage in Utah, Denmark, and Sweden found that the extent that men engage in risky behavior does not predict the size of the female survival advantage.

Different rates of alcohol and tobacco usage by men and women contribute to the paradox, in developed countries. It has also been stated that men suffer from smoking related conditions more than women.

Behavioral factors, like men smoking more than women and engaging in more coronary prone behavior, as well as biological factors, like female hormones, contribute to the female survival advantage.

Diseases

It has been summarized by many studies that men die more than women, in each age group. Women suffer more illnesses than men from adolescence to adulthood. This can likely be attributed to the fact that women have a higher chance of suffering from chronic conditions than men.

The majority of the female survival advantage is accounted for by differences in mortality rates between men and women ages 50-70 due to differing rates of cardiovascular diseases.

This paradox is difficult to detect, especially depending upon the indicators used to identify the phenomenon as well as the phase of the life cycle that each of the participants are in. For example, men have higher rates of cardiovascular diseases, after adjusting the data for the gap in life expectancy. When viewing this statistic, it is important to consider that women have higher rates of cardiovascular disease, in general, because of their longer life expectancy. Women also have higher rates of autoimmune disorders than men.

Overall, men and women suffer from mental disorders at similar rates, but men and women suffer from different kinds of disorders at different rates. For example, men are more prone to experience substance abuse, whereas women are more prone to be diagnosed with depression.

Social factors

It has been concluded that sociological and biological factors both contribute to the paradox.

proposed explanations for the paradox range from genetic, two X chromosomes protecting against recessive genes, hormonal, estrogen protecting against cardiovascular diseases, and behavioral, the expectations around the female sex role making women more willing to seek medical help sooner. There are doubts about the role of hormones due to mixed results in Hormone Replacement Therapy studies on elderly women.

There is also mixed evidence on the role of help-seeking behavior, with some studies reporting that women are more likely to seek medical treatment for all symptoms. But some reporting that women only seek more treatment on malaise type symptoms.

Genetic and physiological factors

Women's superior ability to store excess calories also contributes to their survival advantage. Women have lower mortality rates in high-mortality conditions like famine and epidemics. In such conditions, most of the advantage comes from differences in infant mortality rates.

A research study conducted on flies indicated that the alleles that contribute to male inclusive fitness also harm female health, and thus contribute to the paradox.

Potential bias

Data collected from a research study in Denmark indicated that the paradox is likely due, in part, to selection bias. Women have higher preferences for absenteeism. On average, they are absent from work for health reasons more often than men, including when they do not have objectively worse health.