Sure, they’re delicious. They’re even beautiful. They’re also powerhouses of healthy nutrition.

Now, City of Hope researchers have found another reason to love blueberries. The popular fruit can help control tumor growth, block cancer’s spread and induce cell death in a type of breast cancer that is very hard to treat.

Lynn Adams and Shiuan Chen study the cancer-fighting potential of natural products. (Photo by Larry Kiang)

Triple-negative breast cancer cells frustrate physicians because they lack three key proteins that most standard, successful breast cancer therapies target. This makes triple-negative breast cancer immune to many drugs.

About 15 percent of breast cancer patients have this type. And unfortunately they don’t do as well overall as those with breast cancers having one or more of the target proteins.

Enter our blue-hued hero. These mighty berries may succeed where current drugs struggle, according to Shiuan Chen, Ph.D., director of City of Hope’s Division of Tumor Cell Biology.

“We observed that blueberries help fight triple-negative breast cancers by suppressing pathways critical to tumor development and migration,” he said.

Chen, researcher Lynn S. Adams, Ph.D., and their colleagues applied blueberry extracts to triple-negative breast cancer cells in the lab. They found that the extract slows the development of the cells as well as their ability to move around. Even better, the extract led to apoptosis, or cell death, at more than twice the rate seen in untreated cells.

The team found similar results when they gave blueberry extract to mice with triple-negative breast tumors.

According to Chen, the results give two key reasons to take heart: The anticancer compounds in blueberry extract can be taken by mouth and still have an impact on cancer cells, and the amount given is realistic, equal to a 130-pound adult taking about four ounces daily.

“Our team is hopeful that future research will identify the specific compounds in the fruit responsible for this action, as well as further investigating blueberries’ potential to slow down the progression and spread of this difficult form of breast cancer,” he said.

Chen and his colleagues are planning a human clinical trial to test blueberries’ effect on breast cancer, in addition to research on the anticancer properties of other fruits and vegetables.