Researchers at Georgetown University Medical Center report a protective benefit for 3,3'-diindolylmethane (DIM), a compound metabolized from indole-3-carbinol which occurs in broccoli and other cruciferous vegetables, against damage caused by radiation. They are hopeful that this finding could lead to protective therapies for humans undergoing radiation therapy or otherwise exposed to radiation.
"DIM has been studied as a cancer prevention agent for years, but this is the first indication that DIM can also act as a radiation protector," stated coauthor Eliot Rosen, MD, PhD, of Georgetown Lombardi Comprehensive Cancer Center.
The study involved rats treated with potentially lethal doses of gamma radiation. The animals were divided to receive injections of DIM following periods of up to 24 hours after irradiation. Control groups of rats received injections of an inert substance. "All of the untreated rats died, but well over half of the DIM-treated animals remained alive 30 days after the radiation exposure," reported Dr Rosen, who is a professor of oncology, biochemistry and cell & molecular biology at Georgetown University. "We also showed that DIM enhances the survival time of lethally irradiated mice."
In comparison with untreated animals, mice treated with DIM experienced less of a reduction in red and white blood cells and platelets that normally occurs as a result of radiation therapy. In their introduction to the article, the authors note that low concentrations of the compound have been shown to help protect the cells against oxidative stress.
"DIM could protect normal tissues in patients receiving radiation therapy for cancer, but could also protect individuals from the lethal consequences of a nuclear disaster," Dr Rosen observed.
What I am doing is eating broccoli and other cruciferous vegetables on a regular basis. I anticipate eating a lot of kale this winter because it is growing well and abundantly in my garden, and it is impervious to frost. So, I expect to be harvesting kale regularly from now until April, or at least March.