An antioxidant found in blueberries and grapes may offer protection against colon cancer, according to a new study that suggests the humble berry should be added to the list of cancer-fighting 'superfoods'.
In a small study on rats, the compound appeared to afford the animals a measure of protection against this type of malignancy. All 18 rats were given a compound to induce colon cancer in a manner similar to human colon cancer development. Nine of the rodents were then placed on a balanced diet, while the remainder was given the same diet with a supplement of the berry antioxidant pterostilbene. At the end of eight weeks, the rats on pterostilbene had 57 percent fewer pre-cancerous lesions in their colon in comparison to the control group.
The compound also reduced colonic cell proliferation and inhibited certain genes involved in inflammation, both of which are considered colon cancer risk factors, the researchers reported in a paper published Sunday at the annual meeting of the American Chemical Society in Chicago.
"This study underscores the need to include more berries in the diet, especially blueberries," said Bandaru Reddy, a professor in the department of Chemical Biology at Rutgers University in New Jersey. Separately, researchers at Ohio State University said they had begun clinical trials on humans to see if blueberries could prevent the development of esophageal and colon cancer.
Further studies are needed to establish exactly what the compound does, but researchers suspect that its cholesterol-lowering action may be a key to the link between colon cancer and the high level of saturated fats and calories in Western diets.
In experiments on rats whose diet was five to 10 percent berries, the rats had a 60 percent reduction of tumours of the esophagus and up to an 80 percent reduction in colon tumours.
A third study suggested that chemicals found in grape seed extract may protect against skin cancer by inhibiting the suppression of the immune system caused by ultraviolet light exposure, researchers at the University of Alabama said.
The finding was based on test-tube experiments with mice cells. On a related note, Californian researchers reported that organic produce does offer greater health benefits.
In a head-to-head comparison of organically grown kiwis, versus traditionally grown kiwis, the organic fruit had significantly increased levels of polyphenols, a higher overall antioxidant level and higher levels of Vitamin C. Both sets of kiwis were grown next to each other on the same farm at the same time in the same environmental conditions, the University of California, Davis researchers said.