Why antioxidants may encourage spread of lung cancer rather than prevent it

Antioxidants, once touted as a cancer preventive, may actually spur the disease’s spread. Now scientists have figured out how.Whether taken as a dietary supplement or produced by the body, antioxidants appear to help lung cancer cells invade tissues beyond the chest cavity, two studies report online June 27 in Cell. Experiments in mice and human tissue revealed that antioxidants both safeguard tumors against cell-damaging molecules and prompt the accumulation of the protein Bach1. As Bach1 piles up, tumors burn through glucose at higher rates, thus fueling the cancer cells’ migration to new organs.

“The results provide a new mechanism for how lung cancer cells can spread and may lead to new possibilities for treatment,” says Martin Bergö, a molecular biologist at the Karolinska Institutet in Stockholm who led one of the new studies.

Lung cancer, the leading cause of cancer-related deaths worldwide, claims about 1.6 million lives each year — more than colon, breast and prostate cancers combined. Most lung cancer deaths are related to metastasis. The new findings point to methods of slowing or stopping the spread before it’s too late.