In the 1930s and 40s, the title of "What Cigarette do doctors says causes less throat irritation?" was one that tobacco companies were striving to have you believe. Doctors hadn’t yet discovered a clear link between smoking and lung cancer, and a majority of them actually smoked cigarettes. Regardless, people were connecting the dots, so in cigarette ads, tobacco companies used doctors’ authority to make their claims about their cigarettes seem more legitimate.

“People started to get worried in the ‘40s because lung cancer was spiking; the lung cancer death rate was going through the roof,” says Martha Gardner, a history and social sciences professor at Massachusetts College of Pharmacy and Health Sciences. “People noticed that and were worried about it, but that didn’t mean they knew it was cigarettes.”

Yes, cigarettes did cause coughing and throat irritation. But companies used this to their advantage to promote their product as better than the competition. It wasn’t all cigarettes that gave you problems—it was just those other ones.

The first cigarette company to use physicians in their ads was American Tobacco, maker of Lucky Strikes. In 1930, it published an ad claiming “20,679 Physicians say ‘LUCKIES are less irritating’” to the throat. To get this number, the company’s ad agency had sent physicians cartons of Lucky Strike cigarettes and a letter asking if they thought Lucky Strikes were “less irritating to sensitive and tender throats than other cigarettes,” while noting “a good many people” had already said they were.

 Lucky Strike ads used their answers to imply their cigarettes must be medically better for your throat. In 1937, the Philip Morris company took that one step forward with a Saturday Evening Post ad claiming doctors had conducted a study showing “when smokers changed to Philip Morris, every case of irritation cleared completely and definitely improved.” What it didn’t mention was that Philip Morris had sponsored those doctors.

Philip Morris continued to advertise “studies” it sponsored through the 1940s.

To this end, the R.J. Reynolds Tobacco Company created a Medical Relations Division and advertised it in medical journals. Reynolds began paying for research and then citing it in its ads like Philip Morris. In 1946, Reynolds launched an ad campaign with the slogan, “More doctors smoke Camels than any other cigarette.” They’d solicited this “finding” by giving doctors a free carton of Camel cigarettes, and then asking what brand they smoked.

By the mid-1950s, Science had evolved greatly. There was solid evidence. When tobacco companies had to confront that solid evidence that their products caused lung cancer, advertising strategies started to shift. “What happens is, all the different cigarette companies kind of work together to try to promote the idea that…we don’t know yet if it’s harmful,” Gardner says. In 1954, These companies then formed a research committee to investigate the issue. They also released “A Frank Statement to Cigarette Smokers” arguing that research showing a link between cancer and smoking was "alarming but not conclusive".

Shortly after this, cigarette ads stopped featuring doctors because this was no longer a convincing tactic. Not to mention doctors were now coming out against cigarettes, coinciding with the year 1964, the same year in which the U.S. Surgeon General’s report that smoking causes lung cancer, laryngeal cancer and chronic bronchitis.

Still, tobacco companies continued to maintain, through their research committee, that there was still a “controversy” over whether cigarettes were unhealthy until 1998. That year, the Tobacco Institute and the Committee for Tobacco Research (as it was then known) disbanded in accordance with a lawsuit settlement.