Israeli scientists have said that household products could be contributing to plummeting testosterone levels and exacerbating the global fertility crisis in men.
A research team led by Professor Hagai Levine of Hebrew University-Hadassah told a conference in London this week that their study showed men’s average testosterone levels had halved over the past 50 years.
While rising obesity and diabetes are thought to affect the hormone, Levine said that environmental factors such as endocrine-disrupting chemicals – which can be found in various household items – and global warming could also be factors in the decline.
“I think that we have a major crisis in male reproductive health and it’s currently not given enough attention,” said Levine, who works at the Braun School of Public Health and Community Medicine at Hebrew University.
“We saw an over 50 per cent decline in total testosterone over this time period,” he said.
“It reflects a more than 1 per cent decline each year, so this is not a fluke, this is not a statistical error. It’s very strong trend.”
Testosterone is a hormone that plays an important role not only in sperm production and regulation of libido, but also in maintaining muscle mass and bone density, mood, energy levels and metabolism.
The Israeli team conducted a meta-analysis of six longitudinal studies that tracked changes in testosterone over long periods. These studies measured testosterone levels in 118,593 men from five countries between 1972 and 2019.
“Reproductive health is a very important signal of general health,” said Levine. “We live in an environment that is not ideal for our health in terms of our exposure to chemicals in terms of climate and in terms of health behaviours.”
The Hebrew University team did not control for obesity, which is known to be strongly correlated 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,” Levine said.
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