Why Women Live Longer Than Men

 

By Regina Bailey, Biology Expert ——–

 

According to the Centers for Disease Control and Prevention (CDC), women on average live anywhere from 5 to 7 years longer than men. There are several key factors that influence the life expectancy differences between men and women. Men and boys are more likely to be involved in risky and violent behavior than women and girls. More men die from suicide, murder, car accidents, and cardiovascular related diseases than do women.

 

Men Age Faster Than Women

Scientists believe that the key to why women live longer than men is due to gene mutation. DNA mutations in the mitochondria of men account largely for the differences in life expectancy between men and women. Mitochondria are cell organelles that provide the energy needed for cellular function. With the exception of red blood cells, all cells have mitochondria. Mitochondria have their own DNA, ribosomes, and can make their own proteins. Mutations in mitochondrial DNA were found to increase the rate at which males’ age, thus lowering their life expectancy. These same mutations in females however, do not influence aging. During sexual reproduction, the resultant offspring receive genes from both the father and mother. Mitochondrial DNA however, is only passed on via the mother. Mutations that occur in female mitochondria are monitored through genetic variation so that only favorable genes are passed from one generation to the next.

Mutations that occur in male mitochondrial genes are not monitored so the mutations accumulate over time. This causes males to age faster than females.

Gene mutations in sex chromosomes also influence life expectancy. Sex cells, produced by male and female gonads, contain either an X or a Y chromosome. The fact that females have two X sex chromosomes and males only have one must be taken into account when considering how sex chromosome mutations affect males and females differently. Sex-linked gene mutations that occur on the X chromosome will be expressed in males because they only have one X chromosome. These mutations often result in diseases that lead to premature death. Since females have two X chromosomes, a gene mutation on one X chromosome can be masked as a result of genetic dominance relationships between alleles. If one allele for a trait is abnormal, its paired allele on the other X chromosome will compensate for the abnormal chromosome and the disease will not be expressed.

Sex Hormone Differences

Another contributing factor to the differences in life span between men and women has to do with sex hormone production. Male and female gonads produce sex hormones needed for the growth and development of primary and secondary reproductive system organs and structures. The male steroid hormone testosterone raises levels of low-density lipoproteins (LDL) cholesterol, which promotes plaque buildup in arteries and increases the risk of heart disease and stroke. The female hormone estrogen however, lowers LDL levels and raises high-density lipoproteins (HDL) levels, thus reducing the risk of developing cardiovascular related diseases. Women tend to develop cardiovascular diseases later in life, typically after menopause. Since men tend to develop these diseases earlier in life, they die sooner from them than do women.

Men’s Immune Systems Age Faster Than Women’s

Changes in blood cell composition influence the aging process for both men and women. Women show a slower decline in immune system function than men, resulting in longer life expectancy. For both sexes, the number of white blood cells decrease with age. Younger men tend to have higher levels of lymphocytes than women of similar age, however these levels become similar as men and women get older. As men age, the rate of decline in specific lymphocytes (B cells, T cells, and natural killer cells) is faster than in women. An increase in the rate of decline in red blood cells is also seen in men as they age, but not in women.

7 More Reasons Women Live Longer Than Men

Men tend to live a little more dangerously than women. They often take huge risks and put themselves in harm’s way. These images help to visualize why women live longer than men.

1. Risky Place For Shade
2. Dangerous Kiss
3. Walking a Thin Line
4. Find A Better Place To Stand
5. Open Wide
6. Balancing Act
7. I Think I Can

 

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