It also showed:
- Taking selenium, either alone or in combination with vitamin E, increased the risk of high-grade prostate cancer in men who started the study with high selenium levels, but not in those with low selenium levels.
- Among men who did not take either vitamin E or selenium, those who started the study with high selenium levels were no more likely to have developed prostate cancer than men who started it with low selenium levels. (This means the culprit is added selenium from supplements, not selenium from food.
What the experts say
“I advise all of my patients to absolutely avoid any dietary supplements that contain selenium or vitamin E — including multivitamins,” said prostate cancer expert Doctor Marc Garnick, a clinical professor of medicine at Harvard Medical School, an oncologist at Beth Israel Deaconess Medical Center , and editor in chief of Harvard’s Annual Report on Prostate Diseases.
Writing in Harvard Health, the doc said: “The new data are very troubling, and emphasize that supplements can cause real and tangible harm.
“Any claims of benefits from dietary supplements must be ignored unless large, controlled, and well-conducted investigations confirm such benefits — which I believe will be a very rare occurrence.”