I mean, it says what happened right there in the article, and no the problem wasn't "corporate media telling yuppies" anything. In reality, people of lower socioeconomic status are more likely to develop an alcohol use disorder and to suffer serious health consequences from alcohol use, and blaming "yuppies" does a disservice to anyone who needs to hear this message.

One reason for the shift is that researchers now know that there were some procedural flaws in past research, says Dr. Manson. Past studies often compared people who drank alcohol against a mixed group of nondrinkers. Although some of the people in the nondrinking group never drank alcohol, some had stopped drinking because they were recovering from alcohol use disorders and had been heavy drinkers for years before they quit. Others had given up alcohol because of health problems, such as heart disease or diabetes, or because they were taking medications that interacted with alcohol, says Dr. Manson.

"When studies excluded former drinkers and people with underlying health problems, they didn’t show the same alcohol-related cardiovascular benefits," says Dr. Manson.

In addition, the WHF noted that much of the past research on alcohol and heart health consisted of observational studies — not the more reliable randomized controlled trials. When randomized trials were conducted, they failed to find a heart benefit from drinking alcohol. Also, some of the most favorable effects of alcohol had been found in studies paid for by the alcohol industry, which raised the potential of bias.