THURSDAY, May 27, 2004 (HealthDayNews) -- Want to know two of the biggest risk factors for an early death? How about being young and male.
That's the conclusion of a new study that found the risk of premature death is particularly high for males in the years surrounding sexual maturity, but it persists in later years as well.
"Being male is now the single largest demographic risk factor for early mortality in developed countries," said Daniel Kruger, a social psychologist at the University of Michigan Institute for Social Research.
He's co-leader of the study, which appears in the June issue of Evolutionary Psychology. He will also present the findings at the American Psychological Society annual meeting May 28 in Chicago.
The danger of being male rather than female is concentrated in the years between adolescence and adulthood, the study found. In those years, the death rate for men is nearly three times higher than for women.
But the difference exists years later. In the United States, the death rate for men up to the age of 50 is 60 percent higher than for women. Even at age 75, the male death rate is 46 percent higher. Overall, American men have higher mortality rates for 11 causes of death, ranging from heart disease to homicides to suicides, the study found.
"The magnitude of the sex difference is most starkly summarized by the numbers of deaths before age 50," Kruger said. "For every 10 premature female deaths, 16 men died prematurely."
Kruger and Dr. Randolph Nesse, a professor of psychiatry at the University of Michigan Medical School, got their numbers from the U.S. National Center for Health Statistics, the World Health Organization and the global Human Mortality Database. Data from 20 countries revealed the same pattern -- higher male mortality, with a peak difference at the age of sexual maturity.
The overall ratio of U.S. male-to-female mortality rates increased sharply at adolescence, peaking at 2.94 from ages 20 to 24 and slowly decreasing to 1.46 from ages 75 to 79, according to the study.
The highest male-female mortality ratio for a specific cause was 9.03 for suicide from ages 75 to 79, meaning nine men that age killed themselves for every woman who did. The next highest male-female mortality ratios were for homicide (5.72) and non-automobile accidents (4.91) from ages 20 to 24, the researchers found.
One reason for the difference is as old as time, Kruger said. Men --indeed, males of all species -- "compete for status and resources to attract attention and partnership of women," he said. "The higher degree of mating competition among males is the evolutionary reason why females live longer on average in most animal species."
"Not all men successfully get a partner," Kruger added. "Because of this, men are willing to take a higher degree of risk. Women's behavior is shaped by the needs of child care, so they have a decreased tendency for risk-taking."
Much could be done to reduce excess male mortality, Kruger said, mostly by persuading men to follow the rules of a healthy lifestyle -- proper diet, moderate drinking and exercise.
Some societal changes could also help eliminate the causes of early male death, Kruger said. But curiously, reducing the number of weapons in the hands of the American public probably wouldn't help, he said, because the male-female difference persists in countries where handguns aren't generally available.
The new report could also help, Kruger said. By bringing the mortality difference to public attention, "people would have a better idea of what is happening and might pay more attention to men's health issues," he said.
If male death rates could somehow be reduced to those of women, "one third of all male deaths under age 50 would be eliminated," Kruger said.
The National Library of Medicine discusses the major issues of men's health.