New research is moving sweet, petite erries from the shortcake to the lab. And, as if we needed more reasons to pile the tasty fruits on everything from cereal to yogurt, scientists are finding that berries have powerful cancer-reducing potential. A recent study at Ohio State University showed that freeze-dried strawberries inhibited esophageal cancer when fed to rats that had been exposed to a cancer-causing chemical (Toxicology Sciences, 12/99). The freeze-dried berries made up 5 to 10% of the animals' diets—a dose equivalent to two to three cups of berries per day for a person, says the study’s lead author, Dr. Gary Stoner.

Because of differences in animal and human cancers, a smaller serving may have protective effects in people, says Dr. Stoner. He and others are eager to identify the key cancer-fighting compounds in berries in hopes of developing new supplements or drugs, because eating large amounts of the fruits each day is not always practical. Early research turned up some good leads, but considerable debate and uncertainty still exist.

The Berry’s Bounty
Scientists initially investigated a substance called ellagic acid, a plant pigment found in high concentrations in strawberries, raspberries, blackberries, and walnuts. Researchers at Hollings Cancer Center at the Medical University of South Carolina recently showed that in the test tube, ellagic acid kept cancer cells, which normally grow in an out-of-control manner, from dividing. It also promoted a biological process called apoptosis, or "cell suicide," stopping cancer cells dead in their tracks (Cancer Letters, 3/99).

Study author Dr. Daniel Nixon of the American Health Foundation believes that the whole food, rather than an isolated component such as ellagic acid, may confer the greatest benefits. In addition to ellagic acid, berries contain a rich blend of phytochemicals, or plant-based compounds, which may play a role in fighting disease. If certain substances prove to be particularly important, says Dr. Nixon, "We may end up genetically manipulating some of the berries’ contents."

The Red and the Black
Though current data are promising, further study is needed to clarify the role of berries in fighting cancer. Early trials in people are being planned to study their effects on cancers of the esophagus and colon—areas that have shown the greatest success in animal studies. Researchers are optimistic that future research may uncover additional disease-fighting uses for berries as well.

Generous servings of berries, rich in beneficial phytochemicals, are likely to be a healthy addition to any diet. Dr. Nixon counsels his patients to eat raspberries, strawberries, or blackberries along with a variety of multicolored fruits and vegetables. He cautions those with cancer, however, not to forgo standard treatments, because there is no solid evidence that berries actually shrink tumors or prevent tumor recurrences.