Healthy lifestyles appear to support testosterone production in men, even amid a natural decline that occurs after turning 70.
Those are the findings of a comprehensive analysis of more than 25,000 men across the world, exploring the relationship of male sex hormone production with health and lifestyle factors.
Clinically lower testosterone concentrations can have a range of negative influences, including lower energy and mood, loss of muscle, decrease in libido and erectile dysfunction, and changes in bone density into older age.
This new study, published in the Annals of Internal Medicine, digs into the details of natural testosterone decline, particularly among older men.
Drawing on data obtained from nearly a dozen recent studies of thousands of Australian, European and North American men that used “gold standard” mass spectrometry to analyse hormone levels, the research found testosterone remains largely consistent throughout most of adulthood.
It changes when a man turns 70, with a significant lowering of testosterone levels thereafter. At the same time, luteinizing hormone levels appear to increase, something the study authors suggest points to disrupted testicular function.
“Luteinizing hormone – that’s the hormone that the pituitary gland needs to stimulate the testes to make testosterone – starts rising after the age of 70,” says the study’s senior author Professor Bu Yeap, an endocrinologist at the University of Western Australia Medical School.
“So they’ve got testosterone falling while [luteinizing hormone] is increasing: that’s a good indication that there’s impairment of testicular production of testosterone. So the Leydig cells in the testes that [make] testosterone, their function is impaired after the age of 70 years.”
While 70 appears to be the ‘cliff’ from which testosterone levels drop, a subgroup analysis of men without hypertension, diabetes, cardiovascular and pulmonary disease, cancer and cholesterol medication use found the decline was less substantial.
But the quality of a man’s health appears to be a strong factor in preventing testosterone decline.
Factors like cancer, diabetes, low physical activity and higher BMI were associated with lower testosterone levels. Married men were also found to have lower testosterone levels, though it’s potentially due to the stresses of family life and having kids, rather than simply slipping a ring on one’s finger. A previous study by Yeap and his colleagues found men with healthy lifestyles maintained stable testosterone levels as they age.
This 2022 research took baseline testosterone measurements and followed up again four years later.
“And after four years, the average difference in testosterone in those men – and these are really healthy men – was negligible,” Yeap says.
“So the message to men would be that you want to keep yourself as healthy as possible to maintain the body’s own production of testosterone, so you hit the 70s in the best possible condition.”