Philip J. Goscienski, M.D.
When scientists study large groups of people it's pretty clear that drinking about one or two glasses of red wine every day is heart healthy. There's also good evidence that certain ingredients in wine directly affect the inner lining of blood vessels in a beneficial way by making them less susceptible to damage from free radicals. These are unstable molecules that we encounter from many sources in the course of daily living.
But how about grapes or grape juice? There are no clear-cut answers. Polyphenols are the nutrients in wine that protect blood vessels but they are also abundant in the juice of grapes and other fruits. The wine-making process concentrates polyphenols but adds alcohol, which in small amounts may have some additional health benefits. A study that gave similar high marks to both wine and grape juice was funded by a juice manufacturer and no one else has come up with a definitive study.
How interesting that grapes are the source of wine, which for centuries has held a high place in our culture. I suppose that we could make wine from oranges or watermelons but neither of those has much romantic appeal. Grapes have another advantage. Most fruits are rich in antioxidants but when volunteers were given juice made from pears, oranges, melons, grapes, peaches, plums, apples and kiwis, it was grape juice that had the longest-lasting antioxidant effect. Grape juice also lowered blood pressure in hypertensive men but there was no comparison with wine.
It could be that the glitziness of wine and the plainness of fruit juice have led us to exaggerate the benefits of the former while ignoring the advantages of the latter. Some of the more attention-grabbing virtues of red wine such as reducing the risks of prostate cancer or Alzheimer's disease may exist in the juice of grapes or other fruits but revealing them wouldn't make headlines or be of much interest on talk shows.
Comparing wine with fruit juice ignores the fact that whole fruit is what humans relied upon for thousands of generations and that something might actually be lost in the production of juice or wine. Fiber is one example. Wine obviously has none and juice doesn't have much. If your juice or smoothie is made from a concentrate, forget the fiber.
Fiber is the main reason why you can't overindulge in fruit. It takes more than a half-pound of grapes to make a 6-ounce glass of wine. Try adding the grape-equivalent to your next meal. Even if you're a light drinker - only 2 glasses of wine per meal - eating a pound of grapes won't leave you with much room for dessert.
Juices are relatively high in calories, one reason why pediatricians caution parents to limit juice to about 8 ounces a day for children. Further, those juices should be natural, with no added sugars. Some fruit drinks have little or no real fruit ingredients but they are loaded with high-fructose corn syrup.
Wine drinkers may appear to be healthier because of their lifestyle. They tend to eat healthier foods and to exercise, both of which go a long way to preventing heart disease and cancer. Their wine drinking may just be an added hedonistic but healthy habit.
Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at firstname.lastname@example.org.