Black Raspberries Help Prevent Esophageal Cancer

Townsend Letter for Doctors and Patients, Nov, 2001 by Ralph W. Moss

Evidence continues to accumulate that colorful fruits and vegetables (high in antioxidants) can help prevent cancer. In mid-August, scientists at Ohio State University were able to prevent more than half the cancer of the esophagus in experimental rats by feeding them black raspberries mixed into their regular chow {Cancer Res. 2001;61:6112-9.}

Esophageal cancer is among the ten most common cancers worldwide. This hard-to-treat cancer affects 13,300 US residents per year, the great majority of them men. This disease had previously been linked to cigarette smoking and alcohol abuse: people who both smoke and drink heavily have a 100 times greater risk than those who don't. But it is also linked to diets low in fruits and vegetables. The Ohio scientists therefore decided to see if feeding animals a food high in antioxidants could prevent the formation of esophageal cancer.

There are a host of cancer-fighting substances in black raspberries, including calcium, vitamins, phenols and sterols. At 35 weeks, black raspberries significantly reduced tumor incidence and multiplicity of tumors, proliferation of growths as well as precancerous lesion formation. In conclusion, they said, the dietary administration of black raspberries inhibited both the initiation and the promotion of cancer.

One might try to ascribe this benefit to a particular constituent in the black raspberry. However, it is precisely the synergy of the different compounds that makes the whole fruit more effective in fighting cancer than any of its components. The key to cancer prevention, the Ohio scientists said, is in the whole raspberry. The same group had similar findings using freeze-dried strawberries. It is probably true for blueberries, as well, which other groups have shown to have profound antioxidant activity (J Appl Physiol 1999;86:1817-1822}.