Cranberries aren’t only good for preventing urinary tract infections (UTIs). A recent study in Molecular Nutrition and Food Research finds that these bright red fruits may also have potent anticancer properties. Just like blueberries and apples, cranberries are high in natural plant compounds called flavonoids and phenolic acids. These antioxidants protect cells against inflammation, and help prevent damage caused by harmful molecules known as free radicals, which can trigger cells to turn cancerous.
Researchers at the University of Massachusetts-Dartmouth found that extracts of cranberry fruit inhibited the growth of several different types of cancer cells in the lab, including breast and colon cancers. The researchers also reviewed the cancer-fighting capabilities of some of the individual antioxidants in cranberries, including quercetin, anthocyanins, and proanthocyanidins, and found that they all had an effect on certain types of cancer cells. Some of these effects included preventing tumor cell growth, limiting the processes that cause tumors to spread, and triggering the natural process of cell death (apoptosis). Several components in cranberries, such as ursolic acid, also have anti-inflammatory properties, blocking the activity of COX, an enzyme that is involved in inflammation and is produced in large quantities in tumor tissues.
Most of the studies conducted so far have been performed on cells in laboratories. In the one animal study that was published, a cranberry extract significantly slowed tumor growth in mice compared to a control treatment. “Those results were encouraging, but more animal models are needed,” says Catherine C. Neto, PhD, associate professor of Chemistry at the University of Massachusetts-Dartmouth.
Future studies will help researchers better understand how phytochemicals work together to prevent cancer, and how well they can be absorbed by the body’s tissues (bioavailability). “Once it is established whether the compounds in cranberry are bioavailable enough, and if they have a significant effect on tumors in vivo [in the body] in animal models, the next step would be to plan human clinical trials,” Dr. Neto says.
It is still too early to recommend cranberries solely for cancer prevention, but their other health benefits make them a worthwhile addition to any diet. “The UTI-protective benefits are established in humans,” Dr. Neto says. “So if individuals consume cranberry juice or fruit for UTI prevention as part of a healthy diet, there could be an added benefit of potential protection against cancers and other diseases.”
It’s not clear how much you’d need to eat to get the most benefit, but most studies suggest that eating whole cranberries is preferable to drinking their juice. “It’s a more complex mixture of phytochemicals than the juice,” explains Dr. Neto. “Some of the tumor-inhibiting compounds are only present in whole-fruit products, so I think those would have a greater benefit.”
Neto CC, Amoroso JW, Liberty AM. Anticancer activities of cranberry phytochemicals: An update. Mol Nutr Food Res. 2008.52.