[keane]

I didn’t claim there was only one study. The concern is the corporate culture introducing biases into studies. In the tobacco industry, this was a pattern.

[tptacek]

There was overwhelming evidence, some of it preceding modern human health science, that smoking was damaging.

[pfdietz]

Indeed. It's rare in environmental medicine to see an effect as strong as that from smoking. The straw the tobacco industry clung to for a while (it was debunked) was that people who had cancer smoked to sooth their lungs (or, that cancer caused smoking, not vice versa.)