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November 8, 2008: Wine's antioxidant assets
Of late, there has been a spate of reports emanating from the medical community citing wine's effects upon health based on the presence of those components other than alcohol. Much of the new data supports the basic premise discussed in my past commentaries: Moderate consumption of wine and other alcoholic beverages is associated with a longer and healthier life than that of abstainers (an observation supported by a great mass of published evidence). While at least half of the benefits associated with wine consumption appear to be derived from the alcohol itself (conversely, alcohol, when abused, is the only component of wine that adversely affects health), there are other components of wine that contribute to the same benefits, but they are more complex and variable, and less precisely defined. Alcohol's health benefits chiefly favor the cardiovascular system, and are dramatically reflected in reduced risks of atherosclerotic heart attacks, ischemic strokes and limb amputations due to compromised blood supply. Scientific views on the healthful effects of wine's other compounds are not as unanimous, however, but are under increased scrutiny. We are just beginning to peel back the layers of understanding. Most intriguing are the poly-phenolic flavonoids, which can be referred to as antioxidants, according to their most attractive function. Found in grapes, chiefly the skins, their concentrations tend to be higher in red wines (when skins are included in fermentation) than white (when skins are culled). Their functions in the vine are only partially known, antifungal for one. These antioxidants are less available in other alcoholic beverages. Among the best known, and most biologically active, are resveratrol, quercetin and the catechins. The antioxidants with which we are concerned are a class of phytochemicals, compounds of vegetable origin. They are not exclusive to grapes, although grapes are richly endowed with them. They are also found in allium vegetables (onions, leeks, garlic, shallots), broccoli, spinach, blueberries, strawberries, tea and chocolate. For some time, there was doubt about whether antioxidants could be absorbed when ingested as foods and whether they were biologically potent. The most current research has erased any doubt that the antioxidants remain vital when consumed this way. They appear to be even more active than the more renowned antioxidant vitamins A, C and E. At or near the top of the list of causes of death and disability (some the product of human instigation, others not) are diseases of the heart and blood vessels, cancer and degenerative disorders. While the cause and aggravation of these ills may be multiple and varied, free radicals and the process of oxidation also figure heavily into the formula. Free radicals (not a political term!) are highly reactive compounds produced normally as the body uses oxygen. Factors such as smoking, radiation and certain chemicals enhance their production, thus straining, and sometimes over-whelming, the body's natural, enzyme-mediated antioxidant defense system. For this reason, there is much interest in supplementing the anti-oxidants derived from food and drink. Some of mankind's most insidious diseases are suspected of being able to be relieved to some degree by antioxidants, among them heart attack, stroke, other complications of blood-vessel disease, cancer, Alzheimer's disease and other dementias and degenerative disorders, immune dysfunction, cataract and macular degeneration. Aging itself may be retarded by antioxidants. Precise formulas for the relief of these conditions are not yet known. There is reason to believe that antioxidants may not always be entirely benign.
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Recent studies of the cardio-vascular system report reduction of the risk of heart attack in the elderly by a diet high in vitamin A (but not vitamins C or E), reduction in the risk of ischemic stroke associated with the antioxidants found in fruits and vegetables (but no benefit from vitamins A, C or E), and improved coronary artery function apparently due to vitamin C. The antioxidants in wine and grape juice favorably modulate the blood clotting that climaxes heart attacks and strokes; they help further by relaxing blood vessels and inhibiting the oxidation of LDL (the "bad") cholesterol to its dangerous form. Similar, but less-established, benefits may result from the antioxidant flavonoids found in tea and chocolate, virtually identical to those of wine. Second in importance to their cardiovascular benefits are wine's antioxidant actions against cancer. As a consequence of its antibacterial effects and the scavenging of destructive superoxides to reduce tissue injury, these compounds may prevent cancers of the stomach and other organs. The antioxidant quercetin has been noted to inhibit the growth of cancer and leukemia cells, and to potentiate anti-cancer chemotherapy. One report has resveratrol initiating a process one might term cancer-cell suicide, but another suggests that antioxidant vitamins may do the opposite, resulting in larger brain tumors in mice. (No harm comes to cancer-free mice of this strain.) While the above mentioned data is solid, the demonstrated or suspected benefits of the antioxidants discussed below are still preliminary. • Improved brain and muscle
function also has been associated with moderate wine
consumption and with inclusion of blueberries, strawberries
and spinach in one's diet. One of the most compelling
studies compared sets of aging twins. The co-twin of each
pair who consumed an average of one to two drinks a day
scored higher intellectually than their counterparts who
drank significantly more or less. An ascetic teetotaler might be inclined to ask, why not eat just fruits and veggies, and shun alcohol? Fear not, there are reasons enough to quaff. Alcohol, in moderation, contributes at least half of wine's cardiovascular benefits, and likely provides numerous other health benefits, and little, if any, risk. In fact, it may even enhance the desired actions of the antioxidants in the enriching form of wine, which is a package that can't be beat. Dr. Harvey Finkel Dr. Harvey E. Finkel is a clinical professor of medicine at Boston University Medical Center and chairman of the Committee on Health of the Society of Wine Educators.
Προσθήκη:
8/11/2008 Για παλαιότερες δημοσιεύσεις κάντε κλικ εδώ. |
