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 university’s website.
Similar changes were not seen in patients taking the higher dose of grape powder
or the resveratrol pills.
The researchers aren’t 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.
