Compounds present in popular spices pepper and turmeric could treat breast cancer by limiting the growth of stem cells that cause a tumor to grow, according to new US research.
Turmeric and pepper have been widely explored as potential cancer treatments but a new study suggests for the first time that they could prevent cancer by targeting stem cells.
Cancer recurs and spreads because conventional chemotherapies do not eleminate cancer stem cells. Researchers from the University of Michigan Comprehensive Cancer Center found that when curcumin, which is derived from the Indian spice turmeric, and piperine, a derivative of black peppercorns, were administered to cell cultures, the number of stem cells was reduced, while normal cells were unaffected. The derivatives were applied to breast cells at the equivalent of about 20 times the potency of what would be consumed in a diet.
Researchers believe that eliminating the cancer stem cells as well as decreasing the number of normal stem cells is crucial in fighting cancer.
They found that piperine enhanced the effects of curcumin, and that the compounds stopped the self-renewal process of cancerous stem cells.
"This shows that these compounds are not toxic to normal breast tissue," said Madhuri Kakarala, lecturer in internal medicine at the University of Michigan Medical School and lead author of the study. "Women at high risk of breast cancer right now can choose to take the drug tamoxifen or raloxifene for prevention, but most women won't take these drugs because there is too much toxicity. The concept that dietary compounds can help is attractive, and curcumin and piperine appear to have very low toxicity."
But because the compounds are still being investigated for their possible role in breast cancer treatment, the researchers note that people shouldn't be adding extra curcumin or piperine to their diets.
Meanwhile, curcumin has many other well known health benefits, particularly in traditional Asian medicine. It's been used to treat gastrointestinal disorders, arthritis and is a powerful antioxidant.
Piperine has anti-inflammatory properties,and is also known to improve digestion and is often used in weight loss treatments. It also has been shown to substantially increase nutrient absorption in combination with other food.
The paper is published online in the November issue of the journal Breast Cancer Research and Treatment.
Source: FoodWeek Online, 14 December 2009, http://www.foodweek.com.au/main-features-page.aspx?ID=6016