Black raspberries slow cancer growth

Washington, Aug 28 : A mix of preventive agents, like those found in black raspberries, may more effectively inhibit cancer growth than single agents aimed at shutting down a particular gene.

Researchers at the Ohio State University (OSU) Comprehensive Cancer Centre examined the effect of freeze-dried black raspberries on genes, altered by a chemical carcinogen in an animal model of esophageal cancer.

The carcinogen affected the activity of some 2,200 genes in the animals' esophagus in only a single week, but 460 of those genes were restored to normal activity in animals that consumed freeze-dried black raspberry powder as part of their diet during the exposure.

These findings, also helped identify 53 genes that may play a fundamental role in early cancer development and may, therefore, be important targets for chemoprevention agents.

"We have clearly shown that berries, which contain a variety of anti-cancer compounds, have a genome-wide effect on the expression of genes involved in cancer development," said principal investigator Gary D. Stoner, a professor of pathology, human nutrition and medicine at OSU, who studies dietary agents for the prevention of esophageal cancer.

"This suggests to us that a mixture of preventative agents, which berries provide, may more effectively prevent cancer than a single agent that targets only one or a few genes."

Stoner noted that black raspberries have vitamins, minerals, phenols and phytosterols, many of which individually are known to prevent cancer in animals.

"Freeze drying the berries concentrates these elements about 10 times, giving us a power pack of chemoprevention agents that can influence the different signaling pathways that are deregulated in cancer," he said.

"What's emerging from studies in cancer chemoprevention is that using single compounds alone is not enough. And berries are not enough. We never get 100 percent tumour inhibition with berries, so we need to think about another food that we can add."

The report was published in a recent issue of Cancer Research.