From the “damned if you do, damned if you don’t” department: A new study published in the journal Science Translational Medicine has found that taking antioxidant supplements—those magical nutrients purported to fight free radicals and boost overall health—can actually increase the growth rate of cancer.

Researchers at the University of Gothenburg found that antioxidants can double the rate of melanoma metastasis in mice. Last year, another study showed that antioxidant supplementation hastened the development of lung tumors.

Although there are many antioxidant supplements to choose from, these studies focused on supplementation with some of the most common ones: vitamin E, beta-carotene, retinol (a form of vitamin A), and N-acetylcysteine (also known as “NAC”).

Scientists hypothesize a simple explanation: In the same way antioxidants help normal cells to function optimally, they also help cancer cells bypass harm from the body’s immune system. 

This doesn’t mean, of course, that you should stay away from antioxidants entirely. Just get them from natural food sources rather than mega-doses of vitamin supplements. And if you have any family history of melanoma or lung cancer, talk to your doctor about a specialized nutrition plan. 



  1. Scientific American: “Antioxidants May Make Cancer Worse”
  2. Science Daily: “Antioxidants Cause Malignant Melanoma to Metastasize Faster”
  3. WebMD: “Could Antioxidants Speed Up Cancer Progression?”