The usual finding in longitudinal cohort studies has been that light-to-moderate consumers of alcohol tend to be at lower risk for total mortality and show greater longevity of life, even when other lifestyle/demographic factors known to affect longevity are adjusted for in the analysis. The present analysis is important as it presents data on the relation of alcohol intake to total mortality as well as to specific mortality from cardiovascular disease (CVD) and cancer for a very large number of subjects in the USA. It is based on data from more than 300,000 subjects, of whom almost 25,000 died during a follow-up period averaging 8.2 years. There was a very large number of lifetime abstainers which could serve as an appropriate reference group for their analyses. Further, by adjusting for a number of chronic diseases, and carrying out sensitivity analyses with a 2-year lag period for mortality, the investigators improved their ability to avoid having their results affected by “sick quitters.”
The authors conclude that their analysis shows that light and moderate drinkers have a lower risk of total mortality, as well as mortality from CVD, heart disease, and cerebrovascular disease. The protective effects of alcohol for such cardiovascular outcomes were not present for subjects who reported binge drinking or for those reporting what was defined as “heavy” drinking (>7 drinks/week for women and older men, 14 drinks/week for younger men). Interestingly, the mortality risk for light and moderate drinking was also significantly reduced for deaths attributed to cancer; Forum members thought that this may have possibly resulted from subjects with cancer who actually died from CVD having their deaths attributed to cancer. Subjects reporting heavy drinking and those with binge drinking showed increased risk of all-cause and cancer mortality, with no significant effect on CVD outcomes. The key results of the study are that there is a very clear J-shaped curve for the relation of alcohol to mortality, with lower total, cardiovascular, and even cancer mortality rates for light and moderate drinkers who do not binge drink. There was increased total mortality and cancer mortality for those classified as “heavy” drinkers.
Forum Members thought it unfortunate that beverage-specific data were not presented (as in many studies wine, and sometimes beer, drinkers have better outcomes than consumers of spirits), that subjects of all ages (≥ 18 years of age) were included in a single analysis (rather than also presenting results specifically for older subjects, when the outcome events studied usually occur), and especially that women and older men who consumed > 7 drinks/week, and younger men consuming >14 drinks/week were all combined into a “heavy” drinking category. It would have been preferable that the investigators also had a category for those consuming only slightly more than the recommended levels, who may well have had different outcomes than heavier drinkers.
Overall, Forum members considered this to be a well-done study providing additional data supporting a J-shaped curve for the association of alcohol consumption with mortality. Thus, data continue to indicate that light-to-moderate intake of alcoholic beverages without binge drinking reduces total mortality as well as death from CVD or cancer. The cumulative scientific data on this topic are well described in the accompanying Editorial Comment by de Gaetano and Constanzo in the same issue of the journal.
Reference: Xi B, Veeranki SP, Zhao M, Ma C, Yan Y, Mi J. Relationship of Alcohol Consumption to All-Cause, Cardiovascular, and Cancer-Related Mortality in U.S. Adults. J Am Coll Cardiol 2017;70:913–922