The authors state that light to moderate alcohol intake lowers the risk of cardiovascular mortality, but whether this protective effect can be attributed to a specific type of beverage remains unclear. Moreover, little is known about the effects of long-term alcohol intake on life expectancy.
The impact of long-term alcohol intake and type of alcoholic beverages consumed on cardiovascular mortality and life expectancy at age 50 was investigated in the Zutphen Study, a cohort of 1,373 men born between 1900 and 1920 and examined repeatedly between 1960 and 2000. Hazard ratios (HRs) for total alcohol intake and alcohol from wine, beer, and spirits were obtained from time-dependent Cox regression models. Life expectancy at age 50 was calculated from areas under survival curves.
Results showed that long-term light alcohol intake, that is ≤ 20 g/day, compared with no alcohol, was strongly and inversely associated with cerebrovascular (HR 0.43, 95% CI 0.26 to 0.70), total cardiovascular (HR 0.70, 95% CI 0.55 0.89), and all-cause mortality (HR 0.75, 0.63 0.91). Independent of total alcohol intake, long-term wine consumption of, on average, less than half a glass per day was strongly and inversely associated with coronary heart disease (HR 0.61, 95% CI 0.41 0.89), total cardiovascular (HR 0.68, 95% CI 0.53 0.86), and all-cause mortality (HR 0.73, 95% CI 0.62-0.87). These results could not be explained by differences in socio-economic status. Life expectancy was about 5 years longer in men who consumed wine compared with those who did not use alcoholic beverages. The authors conclude that long-term light alcohol intake lowered cardiovascular and all-cause mortality risk and increased life expectancy. Light wine consumption was associated with 5 years longer life expectancy; however more studies are needed to verify this result.
R Curtis Ellison comments: While this is not an especially large study, it represents the long-term follow up of a cohort of men having repeated assessments of alcohol intake; adjustments for previous drinking were made for subjects not drinking at a given examination. The study followed the subjects until a mean survival age of 77 years, until death for 1,130 of the 1,373 participants. Adjustments were made for smoking, co-morbidities, and socioeconomic status. Data on the pattern of drinking (regular versus binge) were not available.
The frequency of alcohol use increased over time and the average amount increased until 1985, then decreased. The largest proportion of the alcohol in this cohort came from spirits, but the proportion coming from wine increased and that from beer decreased in later years. With repeated assessments over time (up to 40 years of follow up), the long-term intake was estimated as the cumulative average intake; the average intake of alcohol for this cohort was slightly over one typical drink/day.
The most interesting conclusions of this study are that alcohol intake in moderation (< 20 g/day or about 1 _ typical US drinks/day) was associated with 25-30% lower risk of both cardiovascular disease mortality and total mortality. These findings support those from most recent prospective studies. For deaths from coronary heart disease, cerebrovascular disease, all cardiovascular diseases, and all-cause mortality, life-time consumption of wine was associated with lower mortality risks than those associated with the consumption of beer or spirits.
The authors also evaluated the relation between alcohol consumption and survival after age 50. As shown in the figure from the paper below, wine use was associated with greater survival than beer or spirit use, with the no alcohol use group showing the lowest survival.
Wine consumption has been shown in many cultures to be associated with other moderate lifestyle factors, and to be more common among subjects in upper socio-economic classes. In the present study, where subjects were classified into four classes (manual workers, non-manual workers, small business owners, or professionals), wine intake increased over time for all groups, and similar associations between wine and mortality were seen for all classes.
The authors state that the greater inverse association between wine and mortality being seen in all socioeconomic classes suggests to them that the association cannot be explained by confounding by socioeconomic status. While residual confounding by other lifestyle factors (especially pattern of drinking) is still a possibility, we believe that part of the more favourable outcome for wine drinkers in this study may well be associated with the polyphenols and other substances that are present in larger amounts in wine than in other alcoholic beverages.
Source: Long-term wine consumption is related to cardiovascular mortality and life expectancy independently of moderate alcohol intake: The Zutphen Study. J Epidemiol Community Health 2009;000:1-7, doi:10.1136/jech.2008.082198. Streppel MT, Ocké MC, Boshuizen HC, Kok FJ, Kromhout D.