Research: Eating Grapes or Drinking Wine May Prevent Certain Cancers

A new study from the University of California, Irvine suggests that a diet that includes grapes as a regular part, could help prevent colon cancer which will hit about 7% of the population, making it the third most common. Worldwide, close to 500,000 will die from it each year.

They had done previous in vitro studies and those showed that resveratrol, a supplement that is made from a grape extract, is able to block the Wnt pathway. This pathway has been found to be associated with in excess of 85% of all cases of the most common colon cancer, sporadic colon cancers

In this recent study, there were three groups of colon cancer patients. One of the groups received 20mm of resveratrol each day in pill form. Another group drank 120 gr of grape powder mixed with water, and the third drank 80 gr of grape powder daily.

There was no effect on the existing tumors, but when they performed autopsies on colon tissue they found that the Wnt signaling in the patients who had taken the 80 gr of powder had been very significantly reduced. They did not see the same results in the patients who took the higher dose of the powder or in the ones on the pills.
While they cannot say for sure why only the lower dose and not the higher one worked, they think it might be because the active ingredients in grapes have different effects at different doses, which is not surprising since this has been found in other nutritional studies.

As to why the resveratrol pills, which is a chemical that is found in grape skins, did not work they believe that it needs to be combined with other chemicals in the grapes which may play a part in boosting the effectiveness of the resveratrol. Resveratrol is also found in wine and peanut skins.

To put this in everyday terms, 80gr of resveratrol equates out to be about a half glass of wine or 1 pound of fresh grapes. According to the USDA this equals 3 servings of grapes.

The researchers are planning the next step in the study which is going to be a clinical cancer prevention study to see if eating a pound of grapes a day will have the same effect.

In a previous study, they had 499 participants all of whom had colorectal cancer. They found that those who had a family history of the cancer and had a moderate level of wine consumption before they developed the cancer, had improved survival rates. There were 75% who were still alive at the 10 year mark after diagnosis. Those who were not regular, moderate wine drinkers had 47% who were still alive at this point.

The lead researcher on the project is Dr. Randall Holcombe, director of clinical research at the Chao Family Comprehensive Cancer Center at UC Irvine.

The study was funded by the California Table Grape Commission and the UCLA Bionutrition Unit.

Source: UCI http://today.uci.edu/