Skip to comments.Grape powder blocks genes linked to colon cancer
Posted on 11/15/2007 6:04:00 AM PST by Red Badger
Low doses of freeze-dried grape powder inhibit genes linked to the development of sporadic colorectal cancer, University of California, Irvine cancer researchers found.
The study suggests that a diet rich in grapes may help prevent the third most common form of cancer, one that kills more than a half a million people worldwide each year. Around 7 percent of all Americans develop colon cancer during their lifetimes.
Led by Dr. Randall Holcombe, director of clinical research at the Chao Family Comprehensive Cancer Center at UC Irvine, the study followed up on previous in vitro studies showing that resveratrol, a nutritional supplement derived from grape extract, blocks a cellular signaling pathway known as the Wnt pathway. The Wnt pathway has been linked to more than 85 percent of sporadic colon cancers, which is the most common form of colon cancer.
The UC Irvine researchers conducted their study with colon cancer patients. One group was given 20 milligrams daily of resveratrol as a pill; another drank 120 grams daily of grape powder mixed in water; and a third drank 80 grams daily of grape powder.
While the supplements did not have an impact on existing tumors, biopsied colon tissue showed that Wnt signaling in the patients taking 80 grams of grape powder was significantly reduced. 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, they believe that the active components in the grapes may have different effects at low dose than they do at high dose, which is a fairly common finding in nutritional studies.
Holcombe and his colleagues will present their study results Nov. 16 at the Society for Integrative Oncologys Fourth International Conference in San Francisco.
This is truly exciting, because it suggests that substances in grapes can block a key intracellular signaling pathway involved in the development of colon cancer before a tumor develops, said Holcombe.
The resveratrol chemical is found naturally in grape skins, wine and also in peanuts. It is unclear why resveratrol alone was not as effective, but Holcombe believes that other grape chemicals may supplement or boost resveratrols efficacy.
Eighty grams of grape powder equal a half glass of wine or 1 pound of grapes, which is equivalent to three dietary servings of grapes, according to the USDA. Holcombe and his colleagues are currently designing a clinical cancer prevention study to see how a daily diet of 1 pound of grapes affects Wnt signaling.
This study follows an epidemiological survey by Holcombe, Dr. Jason Zell, assistant clinical professor of medicine at UC Irvine, and Dr. Hoda Anton-Culver, chair of epidemiology and director of UC Irvines Cancer Surveillance Program. In this study of 499 colorectal cancer patients, they found that moderate wine consumption before developing colon cancer was associated with improved survival outcomes among those patients with family history of colorectal cancer.
The researchers found that 75 percent of such patients were alive after 10 years of initial diagnosis, compared to 47 percent of such patients who did not regularly drink wine. Study results appeared in the October 2007 issue of Nutrition and Cancer.
Our epidemiologic study suggests that wine consumption may influence survival among a subset of colorectal cancer patients, specifically those with family history of the disease, Zell said. These findings could reflect unique genetic and environmental interactions among familial colorectal cancer patients, but further studies are needed to test this theory. Studies such as Dr. Holcombes with grape powder extract and resveratrol are important as they offer potential explanations for our findings.
Holcombe said researchers have known for a long time that there is a link between diet and cancer. These findings suggest that we should do additional research and clinical studies on grapes and other natural products that may prove effective in helping to prevent cancer, he said.
The grape study received support from the California Table Grape Commission and the UCLA Bionutrition Unit. The authors declare no financial interest or conflicts of interest.
Source: University of California, Irvine
The French, with all their cheese and cream sauces have pretty much concluded that "Wine" is a good thing.
The good thing. It's a natural food...No presription, no regimen, no doctor bills!!
I eat raisins like candy, so I must be okay!..............
In the Bible, grapes and foods made from grapes were very special......now we know why.......
Great...now Welch’s 100% Grape Juice will go up in price again. Aaargh
Love that stuff
So many good California wines. So little time.
Ok, so now where do I go to find “grape powder”?
If the researchers had a consulting relationship with the Grape Commission or stock in a company that stands to benefit from the research results that would be one thing. But if the Grape Commission provides a grant to the University, that isn’t what I would call a conflict of interest.
If the private sector does not sponsor research, that leaves the government and foundations (most of which are lefty). Government control of the research budget is not a good thing.
First rule of science - skepticism. Here is how this sort of study funded by grape growers works. You compare a tablet of red wine (resveratrol) which lacks required dosage; or which has required dosage but is not digestible in tablet form; with grade powder which mixed with water is easily digestible. You get the predictable result: red wine (reserveratrol) tablets don’t work but grape powder does. This tells us nothing and is a scientific trick. Liquid supplements work best, followed by capsules, followed by tablets. Resveratrol supplements come in many forms - some are liquid and are encapsulized in a medical lab under vacuum to preserve potency, some are powder put in a capsule with alcohol, some are hard tablets which may just pass through your digestive system. If you buy resveratrol without alcohol and stabilized in an air tight capsule you will get the true potency. I found it easier and more certain than carrying bottle of grape juice around with me.
How was it established that the tablet used in the study is not digestible?
Does the liquid grapes work?
I do not know how the actual study was performed because the news release does not tell us. I am just guessing that they comparied a solid tablet with a liquid mix of grape powder - the liquid will absorb quicker and better compared to the tablet which needs enzymes to break it down. So the tablet may metaphorically move through your digestive tract without being absorbed; or more accurately put, without being absorbed much. If that is what they did in this study then it is not an apples to apples comparison; or shall we say liquid to liquid study.
In the study the researchers are reporting the grape powder drink mix worked to block abnormal growth pathways. Go down to a vitamin store - check out prices for liquid vitamin C (highest), vitamin C in a capsule(next highest), and vitamin C in a tablet(lowest). Liquid vitamins and supplements are always more expensive and also more effective. Even better is any vitamin in an intravenous shot for instant absorption. Coming soon may be an intravenous shot of resveratrol (grape extract).
Does the liquid grapes work?......I don’t see why not! This calls for a full set of experiments.........Apply for a government grant to see if drinking wine will help keep you healthy. Study might take years to complete, though.........;^)
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.