So, while I wanted to create a blog to showcase some of that, I also expect this will always be more a "Huh. That's interesting." blog - if that - than any kind of an authoritative archive. There are lots of other sources for that.
So, why not start with what seems to me to be one of the most famous "OMG, they actually said that!?!" ads out there, the appeal to authority / appeal to expertise ad for tobacco.
Click to embiggen
If this seems outrageously unlikely to a generation where smoking has become not only known for the health risks it does present, but also a convenient scapegoat for dozens of problems it contributes to only marginally and rarely, if at all, keep in mind, it weren't always so.
Now, doctors will happily tell you if you even say the word "tobacco" while pregnant, your unborn baby will burst into flames and explode killing not only you and the fetus, but everyone unfortunate enough to be within a three mile radius. If you think I'm being facetious, make yourself up to look pregnant then try pretending you're going to light a cigarette - you'll find most everyone around you has got the memo referenced above and takes it very seriously.
But, when my mother was pregnant in the early sixties, doctors already knew smoking wasn't great for the fetus - but they al;so knew stress wasn't great for it, either. Far, far worse, in fact, than a little occasional smoke. So, they actually told my mother (and other pregnant women) that if she - occasionally - started to feel too upset or anxious, she should smoke a cigarette to relax.
To the best of my knowledge, my mother's doctor did not, however, specifically suggest Camel brand cigarettes for this purpose. ;)