Link Between Muscle-Building Supplements And Testicular Cancer Found

Men who reported taking muscle-building supplements, such as pills and powders with creatine or androstenedione, reported a significantly higher likelihood of having developed testicular cancer than men who did not use such supplements, according to a new study in the British Journal of Cancer.
 
Moreover, the associated testicular germ cell cancer risk was especially high among men who started using supplements before age 25, those who used multiple supplements and those who used them for years.
 
Testicular cancer incidence rose to 5.9 cases per 100,000 men in 2011, from 3.7 cases in 100,000 in 1975. Researchers aren't sure why.
 
The study is the first analytical epidemiological study of the possible link between supplements and testicular cancer. The work was inspired by mounting evidence that that at least some supplement ingredients may damage the testes.
 
To conduct the study, the researchers conducted detailed interviews of nearly 900 men - 356 of whom had been diagnosed with testicular germ cell cancer, and 513 who had not. In the interviews, researchers asked the men not only about their supplement use but also about a wide variety of other possible factors such as smoking, drinking, exercise habits, family history of testicular cancer, and prior injury to their testes or groin.
 
After tallying their data and accounting for all those possible confounders, as well as age, race, and other demographics, the researchers found that the men who used supplements had a 1.65 odds ratio (a 65 percent greater risk) of having developed testicular cancer compared to the men who did not use supplements.
 
The odds ratios increased to 2.77 (a 177 percent greater risk) among men who used more than one kind of supplement, and to 2.56 among men who used supplements three years or longer. Men who started using supplements at age 25 or younger also had an elevated associated odds ratio of 2.21, the researchers calculated.
 
"Considering the magnitude of the association and the observed dose-response trends, muscle-building supplements use may be an important and modifiable exposure that could have important scientific and clinical importance for preventing testicular germ cell cancer development if this association is confirmed by future studies," the authors conclude in the study.
 
Future large epidemiologic studies and lab experiments would be necessary to establish a causal link between supplements and testicular cancer.
 
Based on material originally posted by Brown University.