Beta-carotene, selenium, and folic acid taken at high levels, as some supplement manufacturers suggest, are now proven to increase the risk of developing various cancers.
“It’s not that these nutrients are toxic – they’re essential and we need them, but we need them in a certain balance,” says Tim Byers, MD, MPH, professor of epidemiology at the Colorado School of Public Health and associate director for prevention and control at the University of Colorado Cancer Center.
As the senior author of a commentary recently published in the Journal of the National Cancer Institute, Byers discusses the increased cancer risk related to large doses of beta-carotene, selenium, and folic acid.
“The effects of these supplements are certainly not limited to the label we give them. And, as we’ve seen, sometimes the unintended effects include increased cancer risk,” Byers says.
Currently, the FDA regulates dietary supplements as food. However, Byers suggests, supplements, especially at high doses, are more accurately categorized between food and drugs. Similar to drugs, supplement ingredients are biologically active.
In closing, Byers says, “My conclusion is that taking high doses of any particular nutrient is more likely to be a bad thing than a good thing.”
Source: University of Colorado Cancer Center.