Low to moderate alcohol consumption provides no health benefits, according to a systematic review of 107 studies in the March JAMA Network Open. This is contrary to findings of prior studies that found low to moderate alcohol drinking had protective health effects, including longer life expectancy. According to the researchers, the earlier findings were a result of systematic biases in many of the study designs, such as not accounting for healthier lifestyles and behaviors in light to moderate drinkers or that abstainers may be "sick quitters" who stopped drinking for health reasons. Once they adjusted for sampling bias and confounding factors, the protective associations of one to two drinks per day disappeared. They also found an increased risk of mortality for those who had two or more drinks per day.