Page last updated: Tuesday, November 18, 2008
Red Wine Polyphenols in cancer research
by Dr. Erik Skovenborg
In the eyes of science all alcoholic beverages are created equal, however, some drinks may be more equal than others. Red wine may be one of those beverages offering a dual action of alcohol and antioxidants. The name of the game is Red Wine Polyphenols (RWP) - compounds derived from grape tannins and anthocyanin pigments that belong to the most powerful antioxidants in the world. As we absorb polyphenols, they change the properties of blood lipids making LDL-cholesterol more resistant to the sort of oxidation that can trigger atherosclerosis and coronary heart disease.

From Coronary Heart Disease to Cancer

For many years the overwhelming evidence that light-to-moderate alcohol use lowers the risk of coronary heart disease has been in focus. In 2000 Morten Grønbæk with a study of data from 257,859 person-years of follow-up (the Copenhagen Centre for Population Studies) was able to conclude that not only did wine drinkers have significantly lower mortality from coronary heart disease; with a consumption of 1-3 glasses a day wine drinkers also reduced their risk of cancer by 20 percent compared with non-drinkers. As the number of global cancer deaths are rising there is an urgent need of efficient methods of cancer prevention and cancer cure. Earlier studies have found a strong protective effect of intake of fruits and vegetables against cancer. The potential role of red wine polyphenols in cancer prevention may turn out to be one of the most exciting areas of current cancer research.

RWP in cancer prevention

In 2000 Elias Castanas, professor of experimental endocrinology at the University of Crete’s School of Medicine in Iráklion, published important papers on the inhibitory action of Red Wine Polyphenols on human breast cancer cells and human prostate cancer cells. In collaboration with Joseph Vercauteren, professor of pharmacology at the Université Victor Segalen in Bordeaux and expert in polyphenols, Elias Castanas added polyphenols derived from from de-alcoholized red wine to cultures of breast cancer and prostate cancer cells. The RWP had an antiproliferative effect on the cancer cell lines in test tube experiments in the laboratory. During a short stay in Crete in the lovely September weather we had the opportunity to ask professor Castanas some questions about his important cancer research.

Assisted cancer cell suicide

To professor Castanas one of the most intriguing discoveries of his laboratory tests is the very low concentrations of polyphenols needed to inhibit cancer cell growth. Traditional chemotherapy is based on a group of cell poisons the success of which depend on whether the poisons kill the cancer cells before they kill the patient. Polyphenols are non toxic compounds; as a matter of fact it looks as if the RWP have very few side effects. So if the polyphenols do not poison the cancer cells, how do they manage to inhibit and eventually kill them? Castanas has an idea that includes the phenomenon of apoptosis: programmed cell death. The general purpose of apoptosis is to have any cell that suffers from irreparable DNA damage kill itself. Maybe the action of RWP on cancer cells can be described as "assisted suicide". Elias Castanas and his colleagues are working hard to find the answers. His laboratory is doing some preliminary animal (mice) studies that seems to back his test tube research on cancer cells. No studies with cancer patients has yet been performed as far as Castanas knows, and besides he warns that such studies are premature. "Science is five years away from proving whether wine’s antioxidant polyphenols do kill breast and prostate cancer cells in humans".

Other polyphenols to look for

In his tests professor Castanas has used several different polyphenols such as quercetin against cancer cell lines. However, an extract of total RWP is what he favours for his experiments. So far more than 200 polyphenols have been identified in red wine, and Castanas has the opinion that the combined group of polyphenols is more active than the single compounds by themselves.

Professor Castanas has conducted some experiments with tea polyphenols and the results were more or less the same as for RWP. He has not yet had the opportunity to work with beer polyphenols, however, Castanas is familiar with some of the polyphenols in beer. In his opinion there is no substantial mechanistic difference between the polyphenols in wine, beer and tea, however, based on his experience RWP millimol per millimol have a higher antioxidant capacity than other polyphenols.

Bioavailability of polyphenols

The question of bioavailability is a crucial question: if you drink a bottle of full-bodied red wine you consume about 2 grams of RWP; what part of these healthy compounds is absorbed during the process of digestion to become available to target tissues like the endothelial cells of blood vessels or the nerve tissue of the brain? Professor Castanas has good news to wine drinkers: alcohol protects the RWP, so a glass of Cabernet Sauvignon is a good vehicle for polyphenols. For those who want a steak on the plate to go with their Cabernet here is more good news: proteins have a dual action protecting the RWP from oxidation and increasing the bioavailability of the healthy compounds. That added bonus leads directly to Elias Castanas’ favourite advice concerning a sufficient daily intake of polyphenols: eat a normal meal with a variety of foods like fruit, vegetables, legumes, olive oil, bread and fish accompanied by moderate consumption of wine.

Polyphenols on the table or in a capsule?

Who wants to spend hours in the kitchen scraping carrots, cleaning fish and peeling fruit? Why not relax in the sun with an exciting book washing down a capsule of RWP with Dry Martini? No, says the Cretan professor, the antioxidant activity of extracts of polyphenols is poor compared to the antioxidant power of polyphenols from natural fruits and vegetables. Besides there is always the problem of protecting the extracted polyphenols from oxidation. With an ample supply of antioxidants from various sources like fruit, vegetables, vegetable oils and wine you arm the cells of your body with heavy antioxidant artillery to face any oxidant threat.

Professor Castanas is a founder member of the Greek academy of taste. As a bon vivant with an intimate knowledge of the best restaurants on the island of Crete the choice between a RWP-capsule and the fine cuisine of Crete is easy. Raising a glass of fragrant Mirambelo, a red wine from the grape varieties Kotsifali and Mandilaria picked from the mountain vineyards of Peza, Castanas toasts the conclusion from the landmark article on wine and health by St. Leger and A. Cochrane (Lancet 1979;i:1017-21): "If wine is ever found to contain a constituent protective agent against I.H.D. then we consider it almost a sacrilege that this consituent should be isolated. The medicine is already in a highly palatable form".

Dr. Erik Skovenborg is a founder member of the Scandanavian Medical Alcohol Board, a specialist in alcohol and health and a member of the AIM Editorial Board.

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