– FRIDAY, Dec. 11 (HealthDay News) — Compounds derived from two spices — pepper and turmeric — could help prevent breast cancer by limiting the growth of stem cells that promote tumor growth, a new study shows.

When curcumin (from turmeric) and piperine (from black peppers) were applied to breast cells in the laboratory, the number of stem cells decreased, but there was no change in normal cells, say researchers at the University of Michigan Comprehensive Cancer Center.

The study appears online in the journal Breast Cancer Research and Treatment.

“If we can limit the number of stem cells, we can limit the number of cells with potential to form tumors,” the study’s lead author, Dr. Madhuri Kakarala, a clinical lecturer in internal medicine at Michigan’s medical school and a research investigator at the VA Ann Arbor Healthcare System, said in a university news release.

The researchers indicated that the finding that curcumin and piperine are effective against stem cells but not toxic to normal breast tissue has important implications for women.

“Women at high risk of breast cancer right now can choose to take the drugs tamoxifen or raloxifene for prevention, but most women won’t take these drugs because there is too much toxicity,” Kakarala said. “The concept that dietary compounds can help is attractive, and curcumin and piperine appear to have very low toxicity.”

Previous studies have looked at the two dietary compounds as potential cancer treatments, but this was the first to suggest that they may prevent cancer by targeting stem cells.

The finding came with a warning, however. The compounds were tested only in a laboratory and not in people, and the researchers cautioned against anyone adding curcumin or piperine supplements to their diets.

More information

The U.S. National Cancer Institute has more about breast cancer prevention.