Antioxidants can Double the rate of Melanoma Metastasis in mice, new research shows

The results reinforce previous findings that antioxidants hasten the progression of lung cancer. People with cancer or an elevated risk of developing the disease should avoid nutritional supplements that contain antioxidants, the researchers say. Given well-established evidence that free radicals can cause cancer, the research community had simply assumed that antioxidants, which destroy them, provide protection against the disease.

“As opposed to the lung cancer studies, the primary melanoma tumor was not affected,” Professor Bergö says. “But the antioxidant boosted the ability of the tumor cells to metastasize, an even more serious problem because metastasis is the cause of death in the case of melanoma. The primary tumor is not dangerous per se and is usually removed.”

Experiments on cell cultures from patients with malignant melanoma confirmed the new results. “We have demonstrated that antioxidants promote the progression of cancer in at least 2 different ways,” Professor Bergö says. The overall conclusion from the various studies is antioxidants protect healthy cells from free radicals that can turn them into malignancies but may also protect a tumor once it has developed.

Taking nutritional supplements containing antioxidants may unintentionally hasten the progression of a small tumor or premalignant lesion, neither of which is possible to detect. “Previous research at Sahlgrenska Academy has indicated that cancer patients are particularly prone to take supplements containing antioxidants,” Dr. Bergö says.

“Skin and suntan lotions sometimes contain beta carotene or vitamin E, both of which could potentially affect malignant melanoma cells in the same way as antioxidants in nutritional supplements,” Professor Bergö says. “We are testing whether antioxidants applied directly to malignant melanoma cells in mice hasten the progression of cancer in the same way as their dietary counterparts,” http://www.gu.se/english/about_the_university/news-calendar/News_detail//antioxidants-cause-malignant-melanoma-to-metastasize-faster.cid1326572