WASHINGTON Enzyme-blocking chemicals in pomegranates may reduce the risk of estrogen-fueled breast cancers, U.S. researchers said on Tuesday.
An acid found in pomegranates appears to block aromatase, an enzyme that converts androgen to estrogen, a hormone that plays a role in the development of breast cancer, the researchers wrote in the journal Cancer Prevention Research.
"We identified some of these chemicals in pomegranates that actually have properties that can suppress aromatase," researcher Shiuan Chen, of the City of Hope cancer research and treatment center in Duarte, California, said in a telephone interview.
Many women who have had breast cancer take medicines called aromatase inhibitors -- such as Pfizer's Aromasin, Novartis' Femara and AstraZeneca Plc's Arimidex -- to keep estrogen from feeding tumors.
Chen and colleagues studied whether compounds, or phytochemicals, in pomegranates can suppress aromatase and ultimately block cancer growth. They found that 10 natural compounds in the fruit may potentially prevent estrogen-related breast cancer.
Chen said the compounds would not be a replacement for aromatase inhibitors.
"We do not recommend people start taking this as a replacement for the AI's," Chen said. "They (pomegranate compounds) are not as potent as the real drugs so we think that the interest probably is more on the prevention end rather than in a therapeutic purpose."
Other researchers not associated with the study told the journal that the results are promising, and suggested more studies involving animals and humans were needed to confirm the findings.
"It's not clear that these levels could be achieved in animals or in humans because the (compounds) are not well absorbed into blood when provided in the diet," said Gary Stoner of Ohio State University.
Dr. Powel Brown, an oncologist at the University of Texas, said in a statement that future studies should focus on testing pomegranate juice for its effect on estrogen levels, menopausal symptoms, breast density or even as a cancer preventive agent.
More than 400,000 women die from breast cancer globally every year. About 75 percent of breast cancers are estrogen-receptor positive, meaning they are fed by estrogen.
Previous research has shown that pomegranate juice is rich in antioxidants -- vitamins and other substances -- that may help prevent diseases such as cancer, heart disease and Alzheimer's disease. (Editing by Xavier Briand)