Summary:

• The Alcohol Intake and Health Study assessed relationships between alcohol use and health in the U.S., with a focus on morbidity and mortality (i.e., deaths and reduced life expectancy) from health conditions causally related to alcohol use. 
• Most of the evidence evaluated in this report is from systematic reviews and meta-analyses of “observational” cohort studies. It did not include data from quasi-experimental (e.g., Mendelian randomization) studies or randomized controlled trials.
• We assessed relationships between different levels of alcohol consumption and the risk of dying from health conditions that are causally related to alcohol consumption in the U.S. We also modelled the total alcohol-specific mortality at different levels of consumption based on all alcohol-related conditions.
• Among the U.S. population, the risk of dying from alcohol use begins at low levels of average use. Higher levels of alcohol consumption are linked with progressively higher mortality risk. Depending on the level of use, men are at a similar risk of health harms from alcohol use compared to women.
• In the United States, males and females have a 1 in 1000 risk of dying from alcohol use if they consume more than 7 drinks per week. This risk increases to 1 in 100 if they consume more than 9 drinks per week. 
• Males and females who consumed 1 drink per day had an increased risk of liver cirrhosis, esophageal cancer, oral cancer, and injuries, but a lower risk for ischemic stroke. In addition, females had a higher risk for liver cancer and a lower risk for diabetes mellitus when they drank 1 drink per day. However, drinking patterns shape risk. Specifically, even infrequent high per-occasion drinking may eliminate the lower levels of risk for ischemic stroke. 
• Alcohol use is associated with increased mortality for seven types of cancer (colorectal, female breast, liver, oral cavity, pharynx, larynx, esophagus [squamous cell type]). Increased risk for these cancers begins with any alcohol use and increases with higher levels of use. Women experience a much greater risk of an alcohol-attributable cancer per drink consumed.
• ‘Per occasion’ alcohol use refers to how much alcohol is consumed within a short time period, as opposed to how much is consumed on average. Higher levels of per occasion use result in higher blood alcohol levels and higher risks for injuries. Risks increase starting at one drink per occasion and are particularly pronounced for women consuming more than three drinks and men consuming more than four drinks per occasion.
• For individuals who start consuming alcohol at age 15, the risk of an alcohol-attributable death between the ages of 15 and 20 varies by consumption level. The risk of an alcohol-attributable death increases linearly with alcohol consumption. For males, the risk of an alcohol-attributable death ranges from 0.07 (95% CI: 0.05, 0.08) per 1000 for those who consume 1 drink per week, to 1.76 (95% CI: 1.42, 2.28) per 1000 for those who consume 3 drinks per day (i.e., 21 drinks per week). Similarly, for females, the risk increases from 0.03 (95% CI: 0.02, 0.04) per 1000 for those who consume 1 drink per week, to 0.75 (95% CI: 0.57, 1.06) per 1000 for those who consume 3 drinks per day (i.e., 21 drinks per week). Most of these alcohol-attributable deaths are caused by road traffic crashes, unintentional injuries, and intentional injuries. These deaths represent a substantial proportion of all deaths for individuals 15 to 20 years of age.