Source: Life magazine - December 7, 1936
I think i have seen this ads somewhere with same catch phrase.
Found, this is it https://sh.itjust.works/post/21718706
And from John Hopkins study: Smoking and the Digestive System
First sentence is "Smoking can harm your digestive system in a number of ways. " :)))))
So, camel either put on false ads, or they are doing low quality reasearch and think it is correct.
If the paint was so well preserved on the coatl statue I’d be losing my mind right now. Another lie of cigarettes.
proved again and again in the great laboratory of human experience
Proved. Boy the Qanobs have always been around huh