While the adage remains “An apple a day keeps the doctor away,” adding a pomegranate to the mix might be good, too.

In recent years, pomegranates have grown in popularity, and they’re a rich source of certain vitamins and antioxidant compounds. Now, City of Hope researchers may have found another fruitful benefit: They appear to stop and prevent the growth of certain breast cancers.

Shiuan Chen, Ph.D., director of the Division of Tumor Cell Biology, research fellow Lynn Adams, Ph.D., and their colleagues found that pomegranates contain six compounds that may prevent breast cancer growth. These substances work by blocking aromatase, an enzyme known to play a key role in most breast cancers.

Aromatase helps produce female hormones called estrogens. Most breast cancers depend on estrogen to grow.

Of the six pomegranate compounds, one called urolithin B (UB) has the most powerful effect. It puts the brakes on several ways that cells produce estrogen. And in lab tests, Chen and his team found that UB could stop the growth of estrogen-responsive breast cancer cells.

“By suppressing the production of estrogen, urolithin B and other phytochemicals found in pomegranates can prevent hormone-responsive breast cancer tumors from growing,” said Chen. Phytochemicals are naturally occurring plant compounds that may benefit health.

The other phytochemicals in pomegranates found to inhibit aromatase activity are urolithin A (UA) and several chemically modified versions of UA and UB.

“The results of this study suggest that pomegranate intake may be a viable strategy for preventing breast cancer,” said Chen.