Moderate wine drinking and mortality

Nutrition Research Newsletter, Sept, 2004

A moderate, regular intake of alcoholic beverages is associated with a lower risk of death from coronary artery disease and all causes. However, consumption of alcohol, including wine, increases blood pressure, a main risk factor for CAD and all-cause mortality. For a given blood pressure, the risk of mortality from CAD is higher by a factor of 3 in northern Europe and the United States than in Mediterranean Europe. Mediterranean countries are known for their regular wine intake. The researchers of the present study thus investigated whether consumption of wine or other types of alcohol lowers the risk of death associated with hypertension. They studied a cohort of men from eastern France 13 yrto 21 yr after blood pressure measurements had been made. They examined mortality from all causes and from cardiovascular diseases in drinkers of wine and other alcohol and in abstainers for different levels of systolic (SBP) and diastolic (DBP) blood pressure.

From January 1978 to December 1985, 43,450 men born in Europe and aged between 40 yr and 60 yr came to the Center of Preventive Medicine for a health examination. It has been postulated that some of the nondrinkers were sick and had stopped drinking because of their sickness. That source of bias was at least partly eliminated in the present study by excluding from analysis the subjects who at baseline were at high risk of CAD. The group excluded comprised 1923 subjects with an abnormal electrocardiogram result, 1388 subjects receiving antihypertensive therapy, 451 subjects being treated for hyperglycemia, 1117 subjects being treated for hyperlipemia, 469 subjects being treated for arrhythmia, and 1204 subjects being treated for stable angina. Finally, 315 subjects were excluded for having incomplete data. In the present study, we compared abstainers, wine drinkers, and other drinkers, for a total of 36 583 healthy men at baseline and 4203 deaths.

The examination was a free, routine, extensive health appraisal offered by the regional social security office to 95% of the population in the area. The sample was a cross-section of 375,140 active men (aged 30 yr to 59 yr). The examination included a comprehensive questionnaire on current and past medical history, education, professional and leisure-time activities, smoking habits, and amount and type of alcoholic beverages consumed. The medical examination included an electrocardiogram, chest X-ray, measurement of weight, height, blood pressure (supine position, left arm, after 5 min of rest), and many blood and urine tests. SBP and DBP were both used in the present study.

The questionnaire on drinking included six different beverage categories of which 3 were alcoholic--wine, beer, and aperitifs. For the conversion to grams of alcohol, the researchers assumed that 1 bottle of wine contains 88 g alcohol; 1 bottle of beer, 44 g; and 1 glass of spirits, 15 g. Thus, one drink of wine (120 mL) contains 10.5 g alcohol, which is comparable with one drink of beer (240 mL). The alcohol drinkers were separated into 1) wine drinkers, who did not drink any beer, and 2) other drinkers, who consumed both beer and wine.

In these middle-aged men, the risk of death differed among abstainers, wine drinkers, and other drinkers for a given level of blood pressure. In the highest quartile of SBP (158 mm Hg) and thus among those with the highest risk of death, only moderate wine drinkers had a lower risk of all-cause mortality than did abstainers. No reduction in risk was observed at higher intakes of wine or in drinkers of wine and other alcohols. Only a moderate intake of wine was associated with a lower risk of death from all causes, as was observed in studies not related to blood pressure. However, compared with cardiovascular disease death, the relative risk of death from all causes was lower at most SBP levels by up to 37%.

The mechanisms of the protective effect of wine on cardiovascular and all-cause mortality may not be similar. For cardiovascular death, wine may have a specific effect yet to be explained that protects against the noxious effect associated with high blood pressure. The present results are consistent with the observation that for a given blood pressure, the absolute risk of death from CAD in northern Europe and the United States is much higher than in wine-drinking Mediterranean countries. Thus, the lower death rate from CAD, but also from all causes, observed in Mediterranean countries in relation to hypertension may be due, at least in part, to regular wine consumption.

The results may also be concordant with the observation that in wine-drinking hypertensive subjects, the risk of death from stroke is lower than that in nondrinkers. Because hypertension is a strong risk factor for heart failure, these results also seem of interest in relation to the reported protective effect of alcohol consumption on the risk of heart failure. In the present study, only a moderate intake of wine was associated with protective effects on cardiovascular and all-cause mortality. However, this finding should be confirmed in further studies in which the intake of other alcoholic beverages is not contaminated by an intake of wine.