Acai Berry's Effect on Cancer in Question

Health claims in the media have raised the açaí berry—a rare fruit in the U.S. but common in tropical Central and South America— into a multimillion-dollar nutritional supplement business. Marketers claim the fruit causes weight loss and can prevent and even cure cancer, though the Federal Trade Commission (FTC) has taken marketers to task recently for deception.

While marketers say there is research behind their claims, the research in cancer is still preliminary, based on animal or laboratory, not human, studies. Gary Stoner, PhD, a professor of medicine at the Medical College of Wisconsin, has spent much of his career studying black raspberry’s effect on cancer cells.

“There’s nothing magical about the açaí berry,” says Stoner, who led research on the açaí berry and six other berries’ impact on esophageal cancer in rodents published in the June 2010 issue of Pharmaceutical Research. “It’s a berry that has significant antioxidant potential, but it’s not remarkably greater than any other dark berries.”

In Stoner’s research, rats were treated with a carcinogen for five weeks, then put on diets containing 5 percent of either black or red raspberries, strawberries, blueberries, wolfberries, noni or açaí berries. The seven berry types were nearly equally capable of stopping tumor progression in the rats’ esophagi. “Many of the berry types are potentially effective,” Stoner says.

Other research has shown a similar connection. University of Florida researchers found through an in vitro process that chemical extracts made from açaí berries were able to induce apoptosis, a type of cell death, in leukemia cells.

Sorting through such research can be confusing to cancer patients. To help clarify the açaí berry’s benefits and other health claims, the FTC put together a checklist of five questions for cancer patients to ask their doctors. The agency recommends asking if there is research supporting effectiveness, if there are other treatments or products to reduce your discomfort or symptoms and if the product will conflict with your current treatment plan. They also suggest asking if using the product is proven safe and if there are any potential risks or benefits.

One concern is that the açaí’s antioxidant effects may interfere with certain chemotherapy drugs. Antioxidants work to neutralize free radicals, the molecules with odd, unpaired electrons. Free radicals react with other compounds by stealing electrons to gain stability. The process eventually destroys or damages living cells.

It's a berry that has significant antioxidant potential, but it's not remarkably greater than any other dark berries.

But some chemotherapy drugs kill cancerous cells by inflicting massive free-radical damage. Some argue that antioxidants might protect cancer cells against free-radical-induced destruction.

Chemotherapy drugs that are alkylating agents such as busulfan and carboplatin, anthracyclines such as daunorubicin and doxorubicin, and plant alkaloids such as teniposide and etoposide all kill cancer cells in part by inflicting free-radical damage.

Among tips for avoiding cancer cure scams, the FTC warns, “Natural doesn’t always mean effective. Scammers take advantage of the feelings that can accompany a diagnosis of cancer,” according to the agency.

“Natural doesn’t mean either safe or effective when it comes to using these treatments for cancer. In fact, a product labeled ‘natural,’ can be ineffective and even downright harmful.”

Avoiding supplements is one way to protect yourself from harm. Because some supplements may pack a non-physiologic dose and effect, patients should try to get their antioxidants through food, most experts say. Nutritionist D. Milton Stokes, RD, does not put special emphasis on the açaí berry when giving advice.

“The marketing behind the açaí berry is much stronger than its actual benefit,” he says.

Also, since research has not proven that any single supplement can substitute for a generally healthy diet, the American Cancer Society and many other agencies recommend patients get their nutrients from a diet rich in vegetables, fruits, whole grains and lean proteins, such as fish or beans.