Antioxidants have been long thought of as having a protective effect against cancerous tumors. Much to their surprise, Swedish researchers have found evidence that the opposite is true for some people.
University of Gothenburg professors Martin Bergö, Ph.D.,a researcher at the Sahlgrenska Cancer Center, and Per Lindahl, PhD., a visiting professor, said in an interview that supplementing the diet with the antioxidants N-acetylcysteine (NAC) or vitamin E, can “markedly increase tumor growth and reduced survival by half” in people who have precancerous lung cancer lesions or existing lung cancer.
The paper, "Antioxidants Accelerate Lung Cancer Progression in Mice" was published in the Jan. 29, 2014 issue of Science Translational Medicine, a journal of the American Association for the Advancement of Science. Bergö and Lindahl are the paper’s co-corresponding authors.
The concept that antioxidants can help fight cancer is deeply rooted in the general population and is promoted by the food supplement industry, the paper said. Some scientific studies support this finding.
Researchers chose to study what effect the two antioxidants had on lung cancer because it is the most common form of cancer, aside from skin cancer. Their discovery however came about in an unexpected way.
The research, led by Dr. V.I. Sayin at the University of Gothenburg, used mouse models with lung cancer cells as a control experiment as part of another study. In that study, one group of mice was treated with antioxidants and one group received no treatment.
“We really expected to get a protective effect," Lindahl said referring to the group treated with antioxidants. "When we evaluated the results, to our surprise we saw lung cancer tumors had increased in the treated group by threefold. That prompted us to conduct another study.”
While translating results from animal studies to humans should be done with caution, Lindahl said in this current study, “there are strong arguments that suggest the results may be relevant.”
He pointed to the lung cancer in the animal model.