We all know that common phrase “Women live longer than Men,” and that is exactly true. But why? Is it because men have a risky behavior than women, especially in their early teenage years? Several studies have unveiled that men die earlier than women. In fact, men are more often susceptible to various health diseases at an earlier age.
Natural selection is sure weird at some times. Keep in mind that it doesn’t necessarily favor traits associated with vigor, longevity, and health. What it does is it encourages the reproductive process to increase a person’s lifespan.
Longevity and reproduction are commonly seen in women. From pregnancy, they give birth and then goes to a stage of lactation that can take a toll on their energy and health. Several researchers have concluded that bearing more children resulted in a higher oxidative stress in women. This is more prominent in women that are in their post-menopausal stage. A 2006 study showed that women having more children resulted in a shorter post-menopausal lifespan. Which means the more you produce, the shorter your lifespan will get.
However, it’s a different story to men. Although men don’t bear the cost of pregnancy, they still allocate a great deal of energy, especially when it comes to the reproductive process. Reproductive effort in men means involving themselves in situations involving risky behavior, accumulating a larger body mass, especially in the skeletal muscle mass. All the spent energy of these activities just to maintain muscle for a lifetime is equal to women who are on labor and to the breastfeeding stage, although they are somewhat manageable. Hormones play a vital role in everybody, no matter if it is a man or woman. Physiological mechanisms also help in managing the tradeoffs that result from the conflicting needs of the body. Men’s testosterone levels help on regulating muscle and reproductive behavior, but it comes with a price you have to pay.
Testosterone is more prominent in men compared to women. Although women still produce it but only at small amounts. Testosterone helps men to grow a beard and to change to tone of their voice when they hit puberty. What we didn’t know is that testosterone is also responsible for the significant impact on energy consumption in men. There are several other things that testosterone is responsible off, and these are:
- Increases metabolism
- Boosts the libido
- Helps build muscle
- Promote anabolism
As we can see, testosterone is like a main weapon that man always carry. Although sounding healthy, it can be a win-win situation where it can make or break you.
Indeed, the less fat you have, the better you will look in front of the mirror. However, it comes with a price like making you vulnerable to food shortfalls and various kinds of infection. Acute rises in testosterone levels can increase men’s reproductive efforts, but it causes a negative impact on its physiological demands as a result. Male quolls experience a dramatic one-time rise in testosterone that triggers intense bouts of mating—and very high mortality due to male/male aggression and fat depletion. Females are lucky to live up to three years. Meanwhile, men can barely make it to live more than that.
Testosterone longevity and aging are a bit vague and pose a challenge, combining that with men’s shorter lifespan, it resulted in an analogous situation that needs to be further looked upon. Researchers have gone deep down to historical data to determine the effects of lifespan into men. During the 19th century, especially in China, men get their genitals removed for religious purposes. Not to mention, castration as well. This resulted in a large number of eunuchs during the 17th and 18th century in Asia and Europe. However, this doesn’t show any longevity changes in men’s lifespan. In a Korean study, however, castrated men are recorded to live longer from those who aren’t. These historical studies are not enough to prove such a conclusion.
Scientists have gone far to get a better picture of the effects of testosterone on men’s longevity. A test was conducted to birds where researchers have to increase their testosterone levels to see some effects. And the results are impressive. Birds with high testosterone levels are more active on building multiple nests, ward off competitors, and father more offspring than birds that has normal testosterone levels.
Multiple companies have created testosterone supplements for men to take to ward off the negative effects of reproductive effort and longevity. There’s still a little amount of evidence to prove the claim that men taking testosterone has shorter life spans. A 2014 study shows that senior men who take testosterone experienced an acute, non-fatal myocardial infarction exactly ninety days after taking the supplements. Although it’s good for muscle growth, their organs couldn’t handle to tolerate the metabolic burden. Keep in mind that these effects are only present on older men, which encourages researchers to do further investigation of the study.
Testosterone also causes significant immunological effects to a man’s lifespan. Men are even more prone to various infections than women. Several reasons come into play, including the exposure of men to infection opportunities compared to women. Testosterone suppresses immune function. Estradiol, on the other hand, is the primary sex steroid in women that bolsters immune function.
Not only infection, but cancer is also a primary concern that men should worry. Most especially prostate cancer. Countries that have a population of men with high levels of testosterone are known to exhibit a higher incidence of prostate cancer.
As you can see, natural selection doesn’t only play a vital role in men’s longevity. In short, shorter lifespans and health conditions are due to men’s evolutionary history. But keep in mind that evolution is changing over time. Humans are malleable, and the physiology that supports such malleability is probably why we had evolved with the traits that define us. Men have various reproductive strategies, such as paternal care that contributed to their evolutionary success. But testosterone still plays a crucial role for men in order to reproduce.