Purple grape juice fed to laboratory animals led to significant reductions in both mammary tumour mass and the number of tumours per animal, according to a study presented last week at a scientific conference co-sponsored by Harvard Medical School.
The researchers also found that Concord grape colour extract inhibited the proliferation of rat mammary cancer cells in related cell culture tests.
"These studies indicate that components in Concord grape juice can inhibit the growth of certain types of breast cancer cells in rats," said Keith Singletary, Professor of Nutrition, University of Illinois at Urbana-Champaign, the lead author of the study.
His team of researchers took three different concentrations of Concord grape juice and fed them to female rats a week after the administration of a mammary carcinogen--a tumour-inducing compound. Rats in the control group also received the carcinogen, but were fed fluids with concentrations of calories, carbohydrates and organic acids similar to those in the juice concentrations. At the end of the study, mammary tumour mass was reduced by 28 to 36 per cent in the groups consuming the two higher juice concentrations, compared to controls.
At the same time, the number of tumours per animal was reduced by 45 to 65 per cent, in the same two groups, Singletary said. Concurrent experiments also confirmed that addition of Concord grape colour extract to cultures of breast cancer cells derived from carcinogen-induced rat mammary tumours lead to a significant, dose-dependent inhibition of cell multiplication.
"In addition to our own work, other research has suggest that certain components in grapes, possibly the polyphenols, may have an inhibitory or preventive affect on the growth of breast cancer cells," Singletary said. "And while these findings are preliminary and based on animal-model research, they certainly suggest the need to look more closely at the possible benefits they may eventually offer women."
The research was presented at the International Scientific Conference on Complementary, Alternative and Integrative Medical Research, co-sponsored by Harvard Medical School, UCSF Medical School and the Beth Israel Deaconess Medical Center. Funding was provided by the Illinois Council on Food and Agricultural Research.