The protective effect of alcohol consumption on the incidence of cardiovascular diseases: Is it real? A systematic review and meta-analysis of studies conducted in community settings

Background: This study investigated the dose-response relationship between alcohol consumption and CVD incidence, conducting a meta-analysis of studies focusing on residents from local communities. Further, we examined whether light to moderate alcohol consumption had a protective effect on CVD incidence through a sub-group analysis. Methods: This study conducted a meta-analysis of the relationship between alcohol consumption and CVD incidence, selecting journals published up to December 2017. The alcohol consumption level was classified into non-consumers, light (0.01-10.0 g/day), light to moderate (10.1-20.0 g/day), moderate (20.1-40.0 g/day), moderate to high (40.1-60.0 g/day), and high (> 60.0 g/day) groups. The sub-group analysis was conducted according to the number of comorbidities and age. Results: Seven articles were selected in total for the meta-analysis. The mean Newcastle-Ottawa scale score was 8.14 points, suggesting studies were of high quality. There was a J-shaped dose-response relationship between alcohol consumption level and CVD incidence only in men. In general, light to moderate and moderate consumption lowered CVD incidence (Relative risk (RR) [95% confidence interval (CI)] was 0.68 [0.57-0.81] and 0.72 [0.58-0.90], respectively). In men with 3-4 comorbidities, there were no protective effects of light to moderate and moderate consumption on CVD incidence. In either groups of only men or men and women there were protective effects of light to moderate and moderate consumption on CVD incidence only in those aged between 41 and 65. Discussion: We found that light to moderate and moderate alcohol consumption had a protective effect on CVD incidence, there was no protective effect either in those with at least three comorbidities or people aged 40 or younger. Conclusions: We conclude that not all local community residents experience a protective effect of light to moderate consumption on CVD incidence. As such, it is necessary to recommend a moderate amount of drinking or less for each individual.