Light drinking has positive public health consequences

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We enjoyed reading the well-performed and nicely presented meta-analysis on light alcohol drinking and cancer incidence published by Bagnardi et al. [1.Bagnardi V. Rota M. Botteri E. et al.Light alcohol drinking and cancer: a meta-analysis.Ann Oncol. 2013; 24: 301-308Abstract Full Text Full Text PDF PubMed Scopus (254) Google Scholar]. The authors focus on the increased incidence of several cancers in light drinkers, namely cancer of the breast, oral cavity and pharynx, and small-cell cancer of the oesophagus. They extrapolate an increased mortality from these cancers and suggest that this could be of public health relevance even if the relative risk increase is small, because there are a lot of light drinkers in the world and the aforementioned cancers are frequent. However, this line of reasoning misses the whole picture because: (i) increased incidence of some cancers in light drinkers will not necessarily translate into increased attributable mortality, and (ii) even increased cancer mortality in light drinkers will not inevitably translate into increased overall mortality. Regarding the first point, another meta-analysis published in the journal analysed cancer mortality in light drinkers compared with non- or occasional drinkers [2.Jin M. Cai S. Guo J. et al.Alcohol drinking and all cancer mortality: a meta-analysis.Ann Oncol. 2013; 24: 807-816Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar]. According to this meta-analysis, the relative risk of cancer mortality is reduced by 9% [95% confidence interval (CI) 6% to 11%] in light drinkers. It is possible that cancers induced by light drinking, even if more frequent, are less aggressive and less often fatal than those occurring in non-drinkers. Regarding the second point, the authors are well aware of an overwhelming literature, to which they contributed, consistently showing that light drinking is associated with decreased all-cause mortality [3.Ronksley P.E. Brien S.E. Turner B.J. et al.Association of alcohol consumption with selected cardiovascular disease outcomes: a systematic review and meta-analysis.BMJ. 2011; 342: d671Crossref PubMed Scopus (1096) Google Scholar, 4.Di Castelnuovo A. Costanzo S. Bagnardi V. et al.Alcohol dosing and total mortality in men and women: an updated meta-analysis of 34 prospective studies.Arch Intern Med. 2006; 166: 2437-2445Crossref PubMed Scopus (712) Google Scholar]. The relative risk of all-cause mortality may be decreased by as much as 17% (95% CI 14% to 20%) in light drinkers [3.Ronksley P.E. Brien S.E. Turner B.J. et al.Association of alcohol consumption with selected cardiovascular disease outcomes: a systematic review and meta-analysis.BMJ. 2011; 342: d671Crossref PubMed Scopus (1096) Google Scholar]. Besides lower cancer mortality, light drinkers indeed experience lower cardiovascular mortality. If any public health conclusion can be drawn from currently available evidence, it is that light drinking is associated with decreased overall mortality, and perhaps even decreased cancer mortality. This should not be concealed by a misplaced emphasis on a slightly increased incidence of several cancers possibly associated with light drinking. The author has declared no conflicts of interest.