Does Selenium Fight Cancer? It Depends

The mineral selenium is one of the biggest nutrients to swirl around the cancer-fighting category. Of all the health news to come out of cancer and vitamins or minerals, this one reigns either supreme or near supreme. But not all studies say the same thing. Some say it does help defend against cancer, others say no. Well, we have a new study that has waded into the discussion on selenium. And it says that, basically, it depends on what type of selenium you’re taking.

Scientists are reporting that the controversy surrounding whether selenium can fight cancer in humans might come down to which form of the essential micronutrient people take. As it happens, not all version of selenium are equivalent. They found that one type of selenium supplement may produce a possible cancer-preventing substance more efficiently than another form of selenium in human cancer cells. The study appears in the journal “Biochemistry.”

Basically, the results have been mixed regarding selenium’s cancer-preventative possibilities. Selenium is used by the human body to produce glutathione peroxidase, which is part of the antioxidant defense system. In this way, selenium helps offset damage that can occur from potentially dangerous molecules known as “free radicals.” It is continuously being studied for possible therapeutic effects on cancer.

In the “Nutritional Prevention of Cancer” clinical study, researchers found that selenium reduced the risk of cancer. But then a later study called the Selenium and Vitamin E Cancer Prevention Trial did not show a benefit. A major difference between the trials was the form of selenium that was used. It is these two types the new study investigated in human lung cancer cells. They are “SeMet” and “MeSeCys.”

The researchers found that MeSeCys killed more lung cancer cells than SeMet did. Also, lung cancer cells treated with MeSeCys processed the selenium differently than cells treated with SeMet. These findings, they say, could explain why studies on the health benefits of selenium sometimes have conflicting results.

SeMet stands for “Selenomethionine,” an amino acid containing selenium. MeSeCys stands for “Se-methylselenocysteine” and is an organic compound that contains selenium. It is considered a more promising precursor to anticancer drugs. So the next time you are in the supplement aisle, check the labels first.