WASHINGTON, DC — A study presented today shows black raspberries inhibit oral cancers in animals and identifies key cancer-related genes that may explain its actions.
The study, one of over 140 posters presented at the American Institute for Cancer Research (AICR) Research Conference, is not yet published and has not yet gone through the peer-review process.
“Our study shows that feeding black raspberries to rats inhibits the development of oral cancer in an animal model,” said Steve Oghumu, PhD, a scientist at the Ohio State University and lead author of the study.
Oral Cancer and Rspberries
Black raspberries are slightly sweet berries native to North America. They are rich in fiber, vitamins and phytochemicals (plant-based compounds).
According to the Oral Cancer Foundation, nearly 50,000 people in the United States will be diagnosed with oral cancer this year. Approximately 10,000 will die from the disease, which affects mostly men and people who use tobacco or drink alcohol.
Evidence from preclinical and clinical trials in humans suggests black raspberries may prevent or slow the development of oral cancers. But there is little understanding of the molecular basis for black raspberries’ beneficial effects.
Previous research identified key cancer-related genes in humans that were switched on or off in response to eating black raspberries. “Our objective in this study was to see whether those same genes were modulated in the rat model so we could determine if we were seeing the same effects,” said Oghumu.
The researchers assigned rats with oral cancer to one of three dietary groups for 16 weeks: a standard diet, a diet containing 5 percent freeze-dried black raspberries, or a diet containing 10 percent black raspberries. A comparison group of rats was cancer-free.
At the end of the study period, researchers analyzed the animals’ tongue and blood for markers associated with inflammation and apoptosis, a type of programmed cell death. In the animals that ate the black raspberries, markers of apoptosis showed signs of promoting cancer cell death and markers of inflammation were reduced, compared to the animals on the standard diet.
The number of tumors on the animals’ tongues was also affected. Tumors in the rats that ate the diet containing 5 or 10 percent black raspberries were reduced by 39 and 29 percent, respectively, compared to the animals on the standard diet.
“That was a very surprising result,” said Oghumu. “We didn’t expect the lower concentration to be more effective.”
Whole Food Approach
This whole food approach to managing oral cancer is appealing, according to Oghumu, because black raspberries are easily obtained and carry few risks.
“This study is important because we confirmed that black raspberries can inhibit carcinogenesis in a rat model, and we have now found a suitable animal model to understand how black raspberries work in inhibiting oral cancer in people.”
Note: Dr. Christopher Weghorst, PhD, Associate Dean for Research and Professor Administration at The Ohio State University is the Principal Investigator of the study.