[This is an ABC podcast]

Dr Karl:

Cigarette packets today show stained yellow teeth, ulcers and lung cancers. They are as far as you can get from the stylish cigarette advertising back in the 1900s. But getting this bit of truth into advertising has been a big fight, every single step of the way.

For most of the 20th century, tobacco advertising was associated with good health, outdoor activities, weight loss - and even endorsements from medical doctors. How did the tobacco companies ever get medical doctors to endorse cigarettes?!?

Today, we know that cigarettes can kill.

In 2015, lung cancer - overwhelmingly caused by cigarette smoking - killed 1.7 million people worldwide. And lung cancer is only one of the ways that smoking kills.

On average, cigarettes will kill one person for each million cigarettes smoked -- but after a time delay of about 25 years from when they first started smoking.

So the six trillion cigarettes that were smoked in 1990 killed about six million people in 2015, 25 years later. About one quarter of these people died from lung cancer, while the remainder died from other causes related to cigarette smoking.

To make those trillions of cigarettes each year needs a lot of high tech.

Today, a typical cigarette machine can make 20,000 cigarettes each minute.

Each individual cigarette generates a profit of about one cent for the tobacco company. So for each million cigarettes sold, Big Tobacco makes about $10,000 - and one human dies. Rather unfairly, the medical costs of that person dying are much greater than $10,000.

So if it's taken so long for cigarette advertising to show that smoking kills, the evidence must not have been very clear right?

Wrong. Way back in 1964, the US Surgeon General released a landmark report stating that smoking definitely caused lung cancer. This finding was based on over 7,000 published scientific papers.

Big Tobacco knows all the research data. But then, they twist and turn.

On one hand, in 1999, Philip Morris, then the USA's biggest cigarette maker, acknowledged that smoking caused lung cancer and other deadly diseases. But the giant British company, Imperial Tobacco took the opposite approach just four years later. In a 2003 court case, they filed documents stating, "Cigarette smoking has not been scientifically established as a cause of lung cancer. The cause or causes of lung cancer are unknown".

So let's look at the big picture of smoking and health, and for that we need to go way back in time.

In 1604, King James I said that smoking was "loathsome to the eye, hatefull to the nose, harmful to the braine [and] dangerous to the lungs ...".

"Dangerous to the lungs"? How dangerous? A persistent cough is one thing, but lung cancer is quite another.

It wasn't until the 18th Century that the medical profession even recognised lung cancer as an official disease. In fact, by the year 1900, there were only about 140 cases of lung cancer in the entire published medical literature.

Around 1900, cigarette smoking was still relatively uncommon. It existed on the cultural periphery, kind of like getting a tattoo.

But within a few decades smoking was a normal part of the culture. Cigarettes had become "one of the most popular, successful, and widely used items of the early 20th Century".

How did Big Tobacco make this massive social and cultural change happen? You guessed it. The key was massive advertising - using celebrities, authority figures and influential public figures.

But then, something bad happened.

To the puzzlement of the doctors at the time, in the 1920s, an epidemic of lung cancer had begun to appear -- and the doctors didn't know why.

There were a number of suspected causes. These included the recent global influenza pandemic of 1918-1919, industrial air pollution, massive amounts of tar laid on the new roads for the new motor car, exposure to poison gas in World War I, mouthwash, salted fish, and - of course - smoking.

It soon became clear that the lung cancer epidemic was getting much worse, and that cigarette smokers were suffering other health effects as well.

So in the mid 1920s the tobacco companies responded - with a very successful advertising strategy. It had three major components.

First, each tobacco company would link their own specific brands with health advantages, compared to their competitor's brands.

Second, they would get medical doctors to be associated with cigarettes.

And third, they cast doubt on all scientific studies discussing the health effects of smoking.

How effective was this? I'll make my way through that smokescreen, next time ...

-Dr Karl Kruszelnicki

Australian Broadcasting Corporation (2019)