Objective: Alcohol marketing has proliferated on digital media, such as websites, social media, and apps. A systematic review was conducted to examine studies of associations between exposure to digital alcohol marketing and alcohol consumption.

Method: Eight electronic databases were searched for "alcohol" and "marketing" through 14 February 2017. Studies were included if exposure to digital alcohol marketing and alcohol consumption, or related attitudes and intentions, were assessed. Studies were excluded if they only measured exposure to alcohol depictions posted online by family and friends. Study quality was also assessed.

Results: In all, 25 studies were included, including 2 randomized controlled trials, 15 cross-sectional studies, and 8 prospective cohort studies. There was a consistent finding across studies that participation and engagement with digital alcohol marketing--such as clicking on an alcohol ad, visiting an alcohol-branded website, liking or sharing an ad on social media, or downloading alcohol-branded content--was positively associated with alcohol use. The effects of simple exposure to digital alcohol advertising were inconclusive. Proper blinding of subjects, measuring exposures before the outcomes, and measuring the exposures multiple times would improve study quality.

Conclusions: Although more research is needed, existing studies suggest that engagement with digital alcohol marketing is positively associated with increased alcohol consumption and increased binge or hazardous drinking behavior. Governments should consider implementing digital alcohol marketing regulations under the precautionary principle as the alcohol industry's self-regulated marketing codes are likely ineffective at protecting populations vulnerable to alcohol-related harm.