Black raspberries have a high concentration of ellagic acid, a powerful antioxidant. Antioxidants destroy free radicals, which are oxygen molecules that damage cells and contribute to chronic conditions like cancer and heart disease. According to the American Cancer Society, the antioxidant properties of ellagic acid have been associated with death of cancer cells in lab tests. Ellagic acid is also in strawberries and pomegranates and is strongest in freeze-dried forms of the fruit and extracts. The ACS warns that ellagic acid may interact with certain prescription medications and should be used with caution by pregnant women.
In addition to its antioxidant properties, ellagic acid also appears to have cancer prevention characteristics. The ACS reports that studies have shown that ellagic acid may help prevent growth of breast cancer cells and help the liver remove cancer-causing substances from the blood. According to Ohio State University, black raspberries may have a role in preventing colon cancer. OSU researchers concluded in a 2009 article in Cancer Research Prevention that topical black raspberry extract may have applications for skin cancer prevention. The Berry Health Benefits Network says that studies at OSU have also shown an 80 percent reduction in esophageal cancer in mice that ate a diet that was 5 to 10 percent black raspberries. OSU is currently conducting human studies regarding the effects of black raspberries on colon and esophageal cancers.
A tumor is a mass of extra cells and can be cancerous when the cells are abnormal and divide uncontrollably. According to the ACS, the ellagic acid in black raspberries may have antitumor properties, based on animal lab studies have found that ellagic acid inhibited tumor growth in the skin, esophagus and lung as well as growth of tumors caused by carcinogens. The ACS also notes that a recent study found that ellagic acid may work against tumors by preventing tumors from forming new blood vessels. The ACS notes that most studies of ellagic acid and tumors are animal studies and more human trials are needed to confirm any results.
Other Health Benefits
Black raspberries are high in anthocyanins, the substance that gives them their deep purple color. According to the Berry Health Benefits Network, anthocyanins may have anti-inflammatory properties and protect the blood vessels. Research has linked anthocyanins to improved vision, heart health, a decreased risk of high blood pressure and improved memory in older adults. The ACS says ellagic acid may also reduce heart disease, birth defects and liver problems and improve wound healing.