Grapes may prevent colon cancer
Reported November 16, 2007
WASHINGTON: A diet that contains grapes may prevent colon cancer the third most common form of cancer that kills more than a half a million people worldwide each year, suggests a new study by researchers in the US.
Researchers at the University of California in Irvine followed up on previous studies that had shown resveratrol, a nutritional supplement derived from grape extract, blocks the Wnt pathway a network of proteins linked to more than 85% of sporadic colon cancers.
In the latest study done on all colon cancer patients, the researchers gave one group 20 mg daily of resveratrol as a pill and told another group to drink 120 grams daily of grape powder mixed in water. A third group was asked to drink 80 grams daily of grape powder mixed in water.
While the supplements did not have an impact on existing tumours, the study showed that Wnt signalling in the patients taking 80 grams of grape powder was significantly reduced, the scientists said on the universitys website.
Similar changes were not seen in patients taking the higher dose of grape powder or the resveratrol pills.
The researchers arent certain why the lower dose of grape powder was more effective than the higher one. However, the scientists believe that the active components in the grapes may have different effects at lower dosage than they do at a higher dosage, which is a fairly common finding in nutritional studies.