Wine and Your Heart

Data regarding the incidence of coronary heart disease (CHD) in different populations have generated a series of hypotheses that protective substances in the diet may counteract the harmful effects of high-cholesterol, high-saturated-fat diets. One such potential food substance is wine, especially red wine. The purpose of this advisory is to summarize the current literature on wine intake and cardiovascular disease. As stated in a previous advisory on alcohol and CHD,1 recommendations for use of a nonessential dietary component with significant health hazards require definitive evidence of benefit. Although population surveys and in vitro experiments show that wine may have limited beneficial effects, more compelling data exist for other less-hazardous approaches to cardiovascular risk reduction.

There are more than 60 prospective studies that suggest an inverse relation between moderate alcoholic beverage consumption and CHD.2 A consistent coronary protective effect has been observed for consumption of 1 to 2 drinks per day of an alcohol-containing beverage; however, higher intakes are associated with increased total mortality.3 4 Although ecological studies support an association between wine intake and lower CHD risk, these studies are confounded by lifestyle, diet, and other cultural factors.4 5 6 7 Most cohort studies do not support an association between type of alcoholic beverage and prevention of heart disease; however, a few have suggested that wine may be more beneficial than beer or spirits.8 9 It remains unclear whether red wine confers any advantage over white wine or other types of alcoholic beverages.

A synthesis of the observational studies is difficult because of wide variations in methodology, measurement error in alcohol consumption, and biological variability in response to alcohol consumption (which tends to underestimate effect). Moreover, consumption may vary over time, and this is often not taken into consideration in observational studies. Consumption of alcohol is associated with age, race, smoking, ethnic background, and education level. Wine drinkers tend to be less fat, to exercise more, and to drink with meals. Statistical modeling that includes potential confounders does not mitigate the beneficial effect of alcohol consumption on CHD. Furthermore, the residual protective effect of wine may be due to unmeasured factors or differences between drinkers and nondrinkers that cannot be adequately controlled for in statistical analyses. Because of these limitations, epidemiological data can be considered to be supportive of the alcohol-CHD hypothesis, but not definitive. More data are needed to clarify the effects of specific types of beverages in diverse populations.

The mortality rate from CHD in France is perhaps half the rate in the United States despite similar intakes of animal fats.10 This has been coined the "French paradox." When potential confounders and differences in reporting are taken into consideration, the gap is narrowed but probably not eliminated. Regional variation in CHD rates and risk factors in both the United States and France makes a simple explanation for the paradox unlikely. Nevertheless, one explanation for the lower risk of CHD among the French is an increased intake of wine, especially red wine.11 An inverse association between moderate
consumption of alcoholic beverages (1 to 2 glasses per day) and CHD has been documented.

However, data regarding the specific effects of red wine are less consistent, possibly for the reasons discussed above. Moreover, the protective effect appears to be influenced by whether the wine is consumed with meals.4 This hypothesis deserves further investigation, because the pattern of consumption of alcoholic beverages may be a marker for other lifestyle factors related to CHD risk.7 A number of dietary factors, such as consumption of fresh fruits, vegetables, and fish and reduced intake of milk products, differ between European populations and can be readily associated with reduced CHD risk