A compound in broccoli has been found to be effective in preventing death following radiation exposure in rats. According to LiveScience, the compound 3,3'-diindolylmethane (DIM) in broccoli and other cruciferous vegetables shows “promise as a cancer-preventive agent, possibly because it boosts DNA repair.”
To determine the possible benefit of DIM in animals exposed to radiation, investigators “exposed 40 rats to a dose of gamma-ray radiation that would normally be deadly.” All the rats not given DIM following radiation exposure died while 60% of the rats given the broccoli compound were alive 30 days later. LiveScience observes:
"If follow-up studies show the treatment works in humans, the compound could be given to people before or right after nuclear exposure to mitigate acute radiation sickness.”