Two superfoods show promise for protecting people from radiation damage—cruciferous vegetables and miso, a food paste made from fermented soybeans. Scientists have identified a specific chemical byproduct, 3,3’diindolylmethane (DIM), derived from the digestion of cruciferous vegetables and especially concentrated in broccoli, that is responsible for the defensive effect. The source of miso’s beneficial properties needs further investigation, but appears to stem from the fermentation process.

Research led by Gary Firestone, Ph.D., of the University of California-Berkley, and physician Eliot Rosen, Ph.D., of Georgetown University, in Washington, D.C., concluded that administering supplemental DIM before or immediately following lethal levels of radiation exposure protected rats from immediate death. If clinical trials with humans are successful, the compound could be used to minimize acute radiation sickness.

A comprehensive research review published in the Journal of Toxicologic Pathology lends credence to miso’s shielding power. Mice that ate miso a week before irradiation appeared to be protected from radiation injury.