Muscle supplements up risk of testicular cancer: study

Jake Gyllenhaal in film "Southpaw" (2015) / Screen capture from YouTube

Muscle-building supplements increase the risk of testicular cancer, a U.S. study has found.

It is the first epidemiological analytical study linking the supplements to cancer, Brown University said Monday, quoting the study’s senior author, Professor Tongzhang Zheng.

He said the observed relationship was “strong” and the longer people used the supplements, the higher the risks.

Titled “Muscle-building supplement use and increased risk of testicular germ cell cancer in men from Connecticut and Massachusetts,” the study said the risks were higher for those who started using the supplements before age 25, those who used multiple supplements and those who used them for years.

/ Courtesy of Twitter

In the British Journal of Cancer, where the study was published, Zheng said the study was inspired by “mounting evidence that at least some supplement ingredients may damage the testes.”

Testicular cancer patients increased from 3.7 cases a 100,000 in 1975 to 5.9 cases a 100,000 in 2011, the study said.

Researchers have suspected several possible causes of the cancer but have not been able to pinpoint them accurately.