Red wine contains beneficial compounds that appear to inhibit the biochemical reactions that result in clogging of human arteries and often lead to fatal heart attacks, according to researchers at the University of California, Davis. The laboratory findings, published in the Feb. 20 issue of the British medical journal Lancet, may explain what has been called the "French Paradox" -- the relatively low rate of coronary heart disease among the French, who consume a fat-rich diet as well as a significant amount of red wine. "Red wine contains several antioxidant compounds that may delay the narrowing of arteries caused by the accumulation of fatty deposits and formation of dangerous blood clots," said co-author John E. Kinsella, an authority on the biochemistry of dietary fatty acids and dean of UC Davis' College of Agricultural and Environmental Sciences. "Regular consumption of modest amounts of red wine may reduce the instance of sickness and death from coronary artery disease." The study was conducted by an interdisciplinary team of researchers including Kinsella, Edwin N. Frankel, Bruce German and Elizabeth Parks, all of UC Davis, and Joseph Kanner, a visiting scientist from the Volcani Center in Israel. In recent years, medical experts have been puzzled by the significantly lower incidence of death from heart disease among the French who, on the whole, consume a high-fat diet. For example, men in France are three to five times less likely to die of heart disease than those in the United States. The UC Davis study suggests that nonalcoholic compounds known as phenolics, which occur in wine, have an important antioxidant effect in the body that prevents narrowing of the arteries and formation of blood clots. Oxidation -- the same basic chemical process that causes fat to go rancid and metals to rust -- encourages the accumulation of cholesterol-rich compounds known as low density lipoproteins (LDLs) in the inner walls of the arteries and blood vessels. Oxidation of LDLs is now believed to play a role in atherosclerosis, the narrowing of the arteries causing heart disease. Oxidation occurs when one atom or molecule gives up an electron to another atom or molecule -- usually oxygen and thus the term oxidation -- resulting in a new oxidized compound. The phenolic compounds in red wine inhibit oxidation because they readily donate electrons. Simply put, before a lipid molecule in the bloodstream can be oxidized, the phenolic compound has already stepped in and donated an electron, preventing oxidation. By inhibiting oxidation of the lipids, the phenolics are in the long run preventing the potentially lethal accumulation of cholesterol-rich deposits in the artery wall and also the formation of blood clots. Kinsella, Frankel and colleagues collected blood samples from adults with normal levels of lipids. In the laboratory, they separated out the LDLs from these blood samples and mixed them with phenolic compounds from several red wines. Using appropriate analytical techniques, they found that oxidation of the LDLs was inhibited by 60 to 90 percent. "The data provide one plausible explanation of the French Paradox, but much remains to be learned about the specific properties and metabolism of phenolic compounds in wine," Kinsella said. "More detailed studies involving animal and, eventually, human trials are needed to confirm this effect and demonstrate that there is no paradox, rather a mechanism accounting for the benefit provided by the nonalcoholic components of red wine, grapes and grape juice." He stressed that the study does not mean that a diet including large amounts of red wine phenolics will totally prevent heart disease or reverse narrowing of the arteries. This depends on a combination of many dietary habits, lifestyle and genetics, Kinsella said. Support for the study was provided through state and federal funds.