Men who take lots of pills and powders to build muscle may be at higher risk of testicular cancer, new research has suggested.
The strongest link was found in men who took the legal substance ‘creatine’ or the illegal steroid ‘androstenedione’ at a young age and for many years after, the study published in the British Journal of Cancer found.
“The observed relationship was strong,” said lead author Tongzhang Zheng in a statement.
“If you used at an earlier age, you had a higher risk. If you used them longer, you had a higher risk. If you used multiple types, you had a higher risk,” Professor Zheng said.
Creatine, widely used as a gym supplement powder, has been described by the Australian Institute of Sport as having “a general evidence base” for use by athletes.
The powder is believed to potentially boost energy levels during intense workouts and to aid muscle recovery.
For this study, researchers interviewed 869 men from the US states of Massachusetts and Connecticut about their use of gym supplements, and adjusted for factors such as age, race, smoking, drinking alcohol, exercise, family history of testicular cancer, and previous groin injuries.
After taking these factors into account, the men who “used” (ingested one or more supplements at least once a week for four weeks or more) the substances had a 65 per cent greater risk of developing the cancer than those who did not.
While the study may have established a cancer link to supplements, further research would be needed to prove a direct cause, especially given the relatively small sample size.