Why do men die "early"? The biological differences in chromosomes and hormones.

In the United States, the last time men and women could hope to live to roughly the same age was in 1900, when the average life expectancy for women was 48 years and for men 46 years. Since the beginning of this century, although a brief period of equilibrium occurred after the 1918-1919 influenza pandemic, the difference in average life expectancy between men and women has widened, only narrowing slightly in recent years. In 1984, the average life expectancy for women in the United States was 78.2 years, and for men, it was 71.2 years-men were 7 years younger than women. Moreover, in all industrialized countries in the world, women live longer than men. Current projections indicate that by 2050, the average life expectancy for women will be 81 years, and for men, 71.8 years. Some scientists predict that due to increased smoking and participation in the workforce, women's health patterns and average life expectancy will become roughly similar to men's. However, so far, there is little indication that this is happening. Why have women in industrialized countries lived longer on average than men this century? The answer begins before birth, when more male fetuses are lost to miscarriage than female fetuses, resulting in a male-to-female birth ratio of 106:100. In the first year after birth, boys have a higher mortality rate than girls, primarily due to genetic and respiratory diseases, and this trend continues, although the life expectancy gap narrows after age 50 or 60. Therefore, even if the number of male and female births were roughly equal each year, and even if women were more susceptible to chronic physical and mental illnesses leading to longer disease duration, women would still live longer on average than men. Some scientists hypothesize that genetic differences make men less dominant. They explain that fetuses receive a total of 46 chromosomes, half from the mother and half from the father. Female germ cells have two X chromosomes, while males have one X chromosome and one Y chromosome. A small number of genes (not one) are located on the male Y chromosome, and these few genes cause testicular development. Conversely, the X chromosome carries many defective genes that can inherit hundreds of diseases. According to research by Dr. Estelle R. Reme, Professor of Physiology and Biophysics at Georgeton University in Washington, D.C., women are stronger than men from the embryonic stage. Women who carry an abnormal gene on their X chromosome have another chromosome with the corresponding normal gene. If the latter gene is dominant, she will not suffer from genetic diseases, even those she carries. Conversely, men lack a normal gene to counteract the effect of the X chromosome carrying the abnormal gene. Dr. Reme further points out that the X chromosome that women have more of may also enhance the function of the immune system, making them more resistant to infectious diseases than men. Research by Dr. Reme and her colleagues has shown a link between men and blood clots that cause cardiovascular disease. Years of animal experiments have confirmed that testosterone promotes the formation of arterial thrombi, which damage the heart and circulatory system; estrogen inhibits the formation of these thrombi. These animal and human studies show that this is why men have a higher incidence of myocardial infarction until women reach menopause and lose the protective effect of estrogen. Dr. Reme says that men's bodies also respond more strongly to stress and produce higher levels of stress hormones. These hormones trigger a "fight or fly" response; blood clots form more quickly, the heart beats faster-and, if a man is unwell, blood pressure temporarily rises and red blood cell count increases, thickening the blood. Dr. Reme says, "At the onset of puberty, men experience cardiovascular damage due to a strong stress response. About 15 years later, around age 30, the first increase in male myocardial infarction cases occurs." Female hormones, especially estrogen, protect women from heart disease after menopause, and women without ovaries have the same incidence of cardiovascular disease as men. Dr. Reme points out that in addition to damaging the cardiovascular system, stressors can also damage the immune system, the gastrointestinal system, and virtually every cell in the body. This occurs because women carry fetuses, ensuring the continuation of the species. All male mammals require a "fight or fly" response to protect pregnant females.