Copyright © 1995 by Jack Challem, The Nutrition Reporter™
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At least eight medical studies have suggested that a glass or two of wine daily protects against heart disease. One reason is that ethanol, the alcohol found in wine, might reduce the tendency for blood platelet cells to aggregate, or clot. Other studies, however, have found that red wine seems to be more protective than white wine, suggesting that some benefits might be unrelated to the alcohol.
What's a teetotaler to do? Drink purple (or red) grape juice, say some researchers. It may be every bit as good as red wine, because both beverages are rich in a group of powerful antioxidants known as flavonoids.
In recent years, researchers have pointed to wine consumption as an explanation for "the French paradox." The French eat almost four times more butter and three times more lard, and they have higher cholesterol levels and blood pressures, than do Americans. Yet the French are 2.5 times less likely than Americans to die of coronary heart disease.
To get a better handle on the benefits of moderate wine drinking, a team of Israeli researchers compared the effects of red and white wine on 20 healthy men. Half of the subjects were given 400 milliliters of red wine and half were given 400 milliliters of white wine daily for two weeks. The amounts were roughly equivalent to two glasses, and each of the wines contained 11 percent alcohol.
Alexandra Lavy, PhD, and her colleagues focused principally on the impact of the wines on blood fats. The "most impressive effect" was the increase in high-density lipoproteins (HDLs) among the men drinking red wine, according to Lavy's report in Annals of Nutrition and Metabolism (Sept/Oct 1994;38:287-94).
Their HDL levels rose by 26 percent and their apolipoprotein A-1 levels, related to HDL, increased 12 percent by the end of the study. HDL, of course, is considered the "good" form of cholesterol since it appears to protect against coronary heart disease. No HDL changes were seen among the white-wine drinkers.
Another positive sign was that all of the subjects had significant increases in blood carotenoid levels after drinking wine. It was not clear, however, whether the carotenoids were in the wine or whether the wine increased their absorption from the diet. On the negative side, red-wine drinkers had a 26 percent increase in triglyceride levels, considered a heart risk factor. And in this case, the researchers found no decrease in platelet aggregation among either the red- or white-wine drinkers.
The value of the flavonoids - regardless of the source - was confirmed by John D. Folts, PhD, director of the coronary thrombosis laboratory at the University of Wisconsin, Madison. "Numerous studies have attributed the observed cardioprotective effects of alcohol consumption to an increase in plasma HDL cholesterol levels, yet some scientists believe that a higher HDL cholesterol level does not fully explain the cardioprotective effects of moderate alcohol consumption," Folts wrote in Circulation (Feb 15, 1995;91:1182-8). So Folts and his associates fed dogs red wine, white wine, or grape juice while measuring blood-clotting factors and blood flow.
Laboratory analyses found both the red wine (Chateauneuf-du-Pape, 1987) and grape juice (Welch's 100 percent natural purple grape juice, without sugar, artificial flavors, or colors) to be especially high in two flavonoids, quercetin and rutin. Levels of these flavonoids were much lower in the white wine.
Folts reported that platelet aggregation was decreased and blood flow increased in the dogs after being given red wine and purple grape juice, whereas white wine provided no significant benefits. He pointed out that other researchers have documented that the flavonoids found in wine, purple grape juice, and other foods decrease platelet aggregation and dissolve existing clots.
"It is therefore possible to speculate that the cardioprotective effects of red wine consumption observed in the French and other populations may be attributed in part to the ethanol content of the wine and in part to the antioxidant and platelet inhibitory properties of other naturally occurring compounds in the wine," Folts wrote in his conclusion. "Because platelet adhesion to damaged endothelium and sub-sequent platelet aggregation are major steps in both thrombosis and atherogenesis, the long-term inhibition of platelet activity by the consumption of flavonoid-containing foods and beverages may retard atherogenesis and prevent thrombosis on a daily basis."
Note: Although the grape juice study used Welch's purple grape juice, we encourage you to try some of the organic grape and other fruit juices sold at natural food stores.
This article originally appeared in The Nutrition Reporter™ newsletter. The information provided by Jack Challem and The Nutrition Reporter™ newsletter is strictly educational and not intended as medical advice. For diagnosis and treatment, consult your physician.