Gender roles in humans evolve with societal shifts, not as a checklist of traits that promote ‘manliness’ in mating systems, as in other mammals such as chimpanzees and lions. While a primal layer exists in how we interpret gender, it is far less likely to depend on that alone. Perhaps that is one reason why a decline in male reproductive health went unchecked. According to scientists, men’s average testosterone levels have halved over the past fifty years, and society at large has a male fertility crisis.
Alarming Decrease of Testosterone
Total testosterone levels in men dropped by 54% between 1972 and 2019, coming to an average decline of over 1 percent every year. The data, presented at the annual meeting of the European Society of Human Reproduction and Embryology in London, have brought up a crisis starved of the attention it needs. Rising obesity and diabetes are expected to play a part in the downward slope. Still, the presence of environmental factors such as endocrine-disrupting chemicals and global heating is not being crossed off.
Obesity often leads to type 2 diabetes, and a study revealed that 40% of obese people are reported to have lower testosterone. In fact, excess body fat increases the conversion of testosterone into estrogen. The global rise in temperatures puts heat stress on Leydig cells, which release testosterone. The increased heat can disrupt testosterone production and also convert some of it into estrogen.
One class of endocrine-disrupting chemicals is PFAS, which are also infamous as ‘forever chemicals’. Notably, in May, the US Environmental Protection Agency (EPA) announced it would repeal limits and delay regulations on PFAS in drinking water, citing that the regulations set by the previous administration were inappropriate.
The report comes as further evidence of a possible decline in male fertility, after a 2017 study by the same team concluded that sperm counts have plummeted steeply over the past 40 years. The study caught the public eye, with the US health secretary Robert F Kennedy Jr. recently describing male fertility decline as an “existential problem.”
A Worldwide Analysis
The meta-analysis combined six previous studies tracking testosterone, including data from 118,593 individuals from Israel, the US, Brazil, Finland, and Denmark, each of which included at least three time points from 1972 to 2019.
The studies were controlled for age, but differences in average ages between the cohorts may have influenced the results. Obesity, however, wasn’t controlled for, which is linked heavily with low testosterone. “If I had to guess – and it’s an educated guess – I would say that maybe one quarter to one half of the decline would be explained by obesity and metabolic syndrome,” said Prof Hagai Levine, of the Hebrew University-Hadassah Braun School of Public Health and Community Medicine in Israel.
However, obesity and diabetes shouldn’t be the only factors at play; the situation is multi-dimensional. The aim is to clarify that, in addition to obesity and diabetes, whether environmental factors also contribute to this.
The T-maxxing Trend and Paradox
Research shows that testosterone levels have declined. We should be concerned and be more alert to what’s going on with our bodies. In this period of concern, the last thing we need is panic, but fear spreads fast with or without evidence. And this is how the trend of “T-maxxing” (taking supplements to increase testosterone) to counter “low T” (low testosterone) gained traction—classic fear-mongering we are all probably used to on social media. Influencers and content creators suggest taking testosterone tests and supplements, making money by appealing to insecurity and doubts over body image in younger men.
Emma Grundtvig Gram, a visiting PhD student from the University of Copenhagen, led a study at the University of Sydney’s Faculty of Medicine and Health analyzing 46 high-reach Instagram and TikTok posts promoting testosterone tests and treatments. None of the posts included in the study cited scientific evidence to support their claims. Individuals rather than health organizations published 85% of these; 67% included direct purchase links, and 72% had financial interests, such as selling tests, supplements, or clinic consultations.
What they don’t tell you is that using testosterone supplements on a healthy system, quite counterintuitively, suppresses sperm production. Prof Allan Pacey, a professor of andrology at the University of Manchester, recalls having patients in his clinic whose sperm production switched off when they took testosterone.
History is witness to how external testosterone can destroy lives. When Germany was divided into West and East Germany, the latter was not a big name in sports. Naturally, when East Germany won 40 gold medals at the 1976 Montreal Olympics, it became an underdog story whose darker side was revealed decades later.
Behind the scenes, a state-sponsored doping program gave German athletes untested steroids and male hormones. Oral Turinabol, a steroid derived from testosterone, was given to girls as young as 12, all just to make them machines that would be on the podium. The price of an Olympic gold medal was unsettling. They developed male-like hair growth, deep voices, infertility, miscarriages, liver and kidney diseases, and even death.
Manosphere Markets Masculinity
The researchers identified four recurring narratives that shape how testosterone is marketed to men online:
- Low testosterone is a crisis that threatens male sexuality
- Rebranding low testosterone as a young man’s issue linked to the idealization of unrealistically muscular bodies
- An emphasis on self-optimization and gym performance, and
- The promotion of a narrow ideal of masculinity portrays femininity as undesirable or shameful for men.
The whole business model of the manosphere influencers dwells on the insecurity of young men, to whom common experiences like fatigue and stress are being sold as signs of low testosterone. For example, one influencer declared: “I was like 3 numbers away from being called a female,” setting a testosterone test score as a scale of masculinity and gender distinction. While a crisis is imminent and clear as day, the misrepresentation of the crisis as one that can redefine sexuality is diabolical.
What Might be at Play
Rather than just by biotic and environmental stresses, human evolution is currently driven much more by social trends and restructuring. Studies that tracked men over long periods have shown that marriage and active participation in hands-on parenting reduce testosterone levels as mating instincts shift toward nurturing ones over time.
Urbanization and the gradual shift from jobs that require manual labor, like agriculture, to white-collar jobs have left most of the population seated in a chair in a crammed cubicle from 9-to-5. Research suggests that a sedentary lifestyle and barely any exposure to sunlight increase the chances of obesity, which deals a blow to testosterone levels.
The human body is a well-rounded system, and one change usually leads to another. Disruptive sleep-wake cycles pump the “stress hormone” cortisol, and ultra-processed foods spike insulin. Both these hormones negatively impact testosterone release. Zinc and magnesium are two important minerals needed to produce and free up testosterone, and they are generally absent in ultra-processed foods.
As Prof Channa Jayasena of Imperial College London comments, the latest observations on testosterone should serve as an important reality check.
Copyright @smorescience. All rights reserved. Do not copy, cite, publish, or distribute this content without permission.
