The 12-week study included 78 men ranging from 50 to 70 years old with low or normal testosterone levels and no history of cardiovascular disease who could commit to a supervised workout program with aerobic and strength training two to three days a week. Researchers randomly assigned men to one of four groups: testosterone supplements with or without supervised workouts, or placebo supplements with or without the exercise program. At the start and end of the study period, researchers measured artery function using a method that increases blood flow inside an artery to whether the inner lining of the artery is healthy and can help the artery to increase in size or dilate. Not surprisingly, testosterone levels climbed more among men who took supplements. On average, 62 percent of men who received these supplements had testosterone levels rise to above average by the end of the study, compared with just 29 percent of men on placebo.
Exercise Benefits Artery Health
But the bigger surge in testosterone levels with supplements didn’t translate into healthier arteries. Artery function and health improved among the men who exercised, but not among those who took supplements without exercising. And among men who did exercise, artery function improved by 28 percent when they didn’t take testosterone supplements, compared with just 19 percent when they did take testosterone. “Other studies have shown that exercise is beneficial for the arteries,” says Bu Beng Yeap, MBBS, PhD, a coauthor of the study and an endocrinologist at Fiona Stanley Hospital in Perth, Australia. “Our study indicates that testosterone treatment, despite increasing the levels of testosterone in treated men, did not have a beneficial effect on artery health, nor did it enhance the effect of exercise training,” Dr. Yeap says.
Study Limitations
While the study results underscore that exercise is a key component to improving health, it’s possible that it was too brief to show meaningful benefits from the combination of testosterone supplements and supervised workouts, says Jesse Ory, MD, a urology fellow at the University of Miami Miller School of Medicine in Florida, who wasn’t involved in the study. Some men who do have low testosterone levels might get energy they need to exercise by taking testosterone supplements, Dr. Ory adds. One limitation of the study is that it didn’t focus specifically on men with what’s known as hypogonadism, or very low testosterone levels. The study results might look much different if researchers focused only on men with hypogonadism who would meet the clinical criteria for treatment with testosterone supplements, says Robert Eckel, MD, past president of the American Heart Association and a professor emeritus at the University of Colorado Anschutz Medical Campus. “Testosterone is not needed unless hypogonadism is accurately diagnosed,” says Dr. Eckel, who wasn’t involved in the study. Up to 1 in 4 men who take testosterone supplements don’t get their hormone levels assessed first, and as many as one-third of them aren’t testosterone deficient, according to the American Urological Association. “The global increase in testosterone use has been very large, particularly among middle-aged and older men who might see it as a restorative hormone to increase energy and vitality,” says senior study author Daniel Green, PhD, also of the University of Western Australia in Perth.
Testosterone Studies With Mixed Results
Some previous studies have linked testosterone supplements to improvements in artery health and function, but others have not. For example, one small study published in 2016 in Translational Andrology and Urology found men with hypogonadism who took testosterone supplements had improved artery health after three months. Another small study published in 2015 in Clinical Endocrinology found testosterone therapy improved artery health in men with hypogonadism after six months. But other previous small studies, including one published in the Journal of Clinical Endocrinology and Metabolism and another published in Clinical Endocrinology found the opposite results. In these studies, men with hypogonadism who took testosterone in this study had worse artery health and function after six months.
Who Needs Testosterone?
Many men who want to stay healthy as they age will be able to get the outcomes they want — including a lower risk of heart disease — by eating well and exercising enough, Yeap says. “Some men might have disorders of the pituitary gland or testes, and be unable to produce testosterone, and in these men testosterone treatment under medical supervision is generally beneficial,” Yeap says. Often, middle-aged and older men have lower testosterone levels that are due to being overweight or having unhealthy lifestyles, without any indication of pituitary or testes disease. “Rather than seeking testosterone prescriptions, these men should be encouraged to engage in healthy lifestyle behaviors, exercise, and reduce excess weight,” Yeap adds. “This would improve artery health, and might also help men feel generally healthier.”
