Berkeley — A compound found in broccoli and related vegetables may have more health-boosting tricks up its sleeves, according to a new study led by researchers at the University of California, Berkeley.
Veggie fans can already point to some cancer-fighting properties of 3,3′-diindolylmethane (DIM), a chemical produced from the compound indole-3-carbinol when Brassica vegetables such as broccoli, cabbage and kale are chewed and digested. Animal studies have shown that DIM can actually stop the growth of certain cancer cells.
This new study in mice, published online today (Monday, Aug. 20) in the Journal of Nutritional Biochemistry, shows that DIM may help boost the immune system as well.
“We provide clear evidence that DIM is effective in augmenting the immune response for the mice in the study, and we know that the immune system is important in defending the body against infections of many kinds and cancer,” said Leonard Bjeldanes, UC Berkeley professor of toxicology and principal investigator of the study. “This finding bodes well for DIM as a protective agent against major human maladies.”
Previous studies led by Bjeldanes and Gary Firestone, UC Berkeley professor of molecular and cell biology, have shown that DIM halts the division of breast cancer cells and inhibits testosterone, the male hormone needed for growth of prostate cancer cells
In the new study, the researchers found increased blood levels of cytokines, proteins which help regulate the cells of the immune system, in mice that had been fed solutions containing doses of DIM at a concentration of 30 milligrams per kilogram. Specifically, DIM led to a jump in levels of four types of cytokines: interleukin 6, granulocyte colony-stimulating factor, interleukin 12 and interferon-gamma.
“As far as we know, this is the first report to show an immune stimulating effect for DIM,” said study lead author Ling Xue, who was a Ph.D. student in Bjeldanes’ lab at the time of the study and is now a post-doctoral researcher in molecular and cell biology at UC Berkeley
The discovery of DIM’s effects on the immune system helps bolster its reputation as a formidable cancer-fighter, the researchers said. “This study shows that there is a whole new universe of cancer regulation related to DIM,” said Firestone, who also co-authored the new study. “There are virtually no other agents known that can both directly shut down the growth of cancer cells and enhance the function of the immune system at the same time.”