Throughout most of human history men, on average, have lived longer lives than women. The main reason was thought to be birth-related mortality. This changed in the 19th century primarily due to advances in health care. Men in almost every country of the world now die younger than women, somewhere between 3-10 years earlier. This is illustrated among a selection of countries in Figure 1. Men are also more burdened by illness during life, for example, they fall ill at a younger age and have more chronic conditions than women. Why is this the case?
Life expectancy is a statistic that quantifies how long, on average, a person’s life is expected to be and is usually calculated from the year of birth.
Figure 1. The average life expectancy for males and females born in either 2000 or 2019 is shown for a selection of countries. Data used is from the World Health Organization.
The main take-home points from Figure 1 are:
- There is a lot of variation in average life expectancy within countries around the world
- Females outlive males in every country
- Life expectancy has increased in all countries over the last two decades, but especially so among the countries with the lowest life expectancies.
Life expectancy is influenced by many factors including physical characteristics, diseases, behaviour choices, type of occupation, wars, geographic location, socioeconomic status and quality of medical care, among other things. This article will explore some the key factors associated with males having shorter lives compared to females:
PHYSICAL factors
- Men are larger than women. Larger animals across many species generally die younger than smaller ones. This is also the case in humans where many studies have confirmed this pattern, even within the sexes. For example, studies on retired pro basketballers and baseballers have shown larger/taller players, on average, die younger than shorter players. Other research has also shown shorter stature is typically associated with lower heart disease risk factors such as high blood pressure and high cholesterol.
This poses a dilemma because there is strong evidence for female attraction towards taller males in almost every population studied. Why choose tall partners if they are more likely to die young?
The answer may be that tall people, particularly tall men, typically earn more money and are held in higher admiration than their shorter colleagues. Also, tall people have a wider selection of mates, are seen to be more desirable by females, and, on average, are more successful. It has been suggested the trade-off between being tall and living shorter lives versus the obvious social benefits of above average height may optimise at around ~6’2” or 188 cm for males.
- Men have more fat stored in the trunk and abdomen. The main male sex hormone – testosterone – is about 15-20 times higher in men versus women at any age following puberty. This helps explain the large advantage males have in muscle size and strength. However, testosterone also promotes fat deposits in the trunk (while higher estrogen levels in females promote fat deposits on their arms/legs and play a beneficial antioxidant role). Abdominal fat in men is associated with increased fatty deposits in blood vessels and higher levels of cardiovascular disease. It can also lower immune function. Studies on castrated men who have much lower testosterone levels show they live about 15 years longer than uncastrated men from similar socioeconomic backgrounds.
- Men are fatter than women. According to recent statistics about 75% of adult Australian males and 60% of females are overweight or obese. Higher levels of body fat, especially in the abdominal area where men tend to store fat, are associated with increased rates of diabetes and heart disease.
BEHAVIOURAL factors
- Men smoke more than women. There is unquestionable evidence that smoking causes lung cancer, heart disease, strokes and many other health problems. Despite this, about 4% more men than women currently smoke in Australia (~16% versus 12% of adults), although it was about 46% higher immediately post WWII when about 75% of men smoked.
- Men drink more alcohol than women. Alcohol consumption is highly skewed, meaning there are a lot of non-drinkers, and less and less excessive drinkers. It is among the more extreme alcohol consumers where health problems begin to occur. Men are about three times more likely to drink to levels posing a health risk over their lifetime, although younger women may be catching up! Overall, excessive alcohol consumption among women is responsible for about 0.7% of their total burden of disease versus about 3.8% in men. Men also have more alcohol-related hospitalisations.
- Men seek medical help less frequently than women. In Australia the medical safety net – Medicare – is a free/small cost service for all citizens. In recent years, the average use of Medicare services by women was 13 consults per year while for men it was only 6. Even in serious cases of cancers and chronic illness males tend to present to doctors at a more advanced stage than women. They are also less likely to participate in health screening and preventive check-ups compared to women.
- Men take more risks which lead to injuries and deaths. To increase their attractiveness to females, males will often exhibit risk-taking behaviours. For example, it has been shown that males make riskier decisions in situations such as speeding, conflict situations, and crossing roads. These patterns are even more pronounced in the presence of females as a form of ‘mate advertising’.
- Male suicide rates are higher at all ages compared to females. Male suicide rates are consistently higher than female rates. They have ranged from nearly six times that of females in the 1930s (the Great Depression years), to less than twice the female rate in the 1960s and early 1970s. Currently in Australia, the male suicide rate is around 3–4 times that of the female rate. The highest age-specific rate for both males and females is in the 40-59 year bracket.
- Men have more dangerous jobs.Men outnumber women in jobs that have some of the highest occupational death rates. Overall, occupational deaths in men are more than 10-fold higher than women. The riskiest occupations in order include farming, transport/warehousing, drivers/machine operators, and working at construction sites. However, even within the same occupations men still have higher death rates compared to women. Fatality rates increase with age but have, in general, decreased over the past few decades.
SUMMARY
The gap in life expectancy between males and females is due to a combination of many factors. This gap can close further with changes in lifestyle choices and behaviours. Not only can life expectancy increase for males it can also translate into better quality years of life.
Written Professor Kevin Norton, University of South Australia.