New research published in the British Journal of Cancer has found that taking muscle-building supplements can increase the risk of testicular cancer by up to 65 percent. The study monitored 356 cancer patients and 513 control subjects, all from Connecticut and Massachusetts.

The case-control study was conducted by researchers from the Yale School of Public Health and the Harvard School of Public Health, and tested for testicular germ cell cancer. About 90 percent of testicular cancers originate from germ cells.

The researchers found the subjects that used multiple muscle-building supplements and those that began using the supplements when they were younger had the greatest risk of developing cancer.