An Australian public service announcement that warns viewers about the carcinogenic effects of alcohol has been ranked as the most effective one of its kind in the world.

The study, funded by the Australian National Health and Medical Research Council and published in British Medical Journal Open, had participants view a total of 83 alcohol use reduction advertisements.

The researchers found that an ad called "Spread" was rated as the most effective in convincing drinkers to reduce their alcohol consumption. The ad features a glass of red wine tipping over and the wine pouring out and forming an anatomical drawing of a woman’s body and blood vessels.

“Alcohol is carcinogenic. Once absorbed into the bloodstream, it travels through the body,” a voiceover says. “With every drink, cell mutations in the breast, liver, bowel and throat increases. These cell mutations are also known as cancer.”

The ad goes on to mention that doctors recommend a limit of two drinks on any given day. Advocates like Cancer Council Victoria CEO, Todd Harper, hope that ads like this one can help educate people about the carcinogenic effects of alcohol. 

“Our 2015 survey of Victorian men and women found that nearly half of the respondents either believed that alcohol made no difference or were not sure if it had any effect on a person’s risk of cancer,” says Harper. “It’s worrying because alcohol is a Group 1 carcinogen – the highest classification available. It means that there is strong evidence that alcohol causes cancer at some body sites in humans.”

Harper believes the research shows that people can be educated—and swayed—by thoughtful mass-media campaigns.

“We’ve seen how effective campaigns around drink driving and short-term harms such as injury or violence have been in terms of changing our drinking habits, but in Victoria and the majority of the rest of Australia, we rarely see the long-term health effects of alcohol portrayed on our screens,” he says.

The least effective advertisement found in this study was titled "Add Nothing," which encouraged viewers to pick water over beer. But it likely was still better than the heroin Superbowl PSA, "All American Girl," which critics and experts found stigmatizing and more likely to frighten than to educate.

A two-drink-per-day limit is an idea that holds water—research by the World Cancer Research Fund has found that consuming three drinks a day can cause liver cancer.