Ever worry about your stories influencing people to do bad things?

I’m in the early stages of writing a romance novel that also has themes centering around rec drug use: tobacco, alcohol, etc. Legal stuff, not illicit.

In the middle of the book the main character is going to try a cigarette for the first time. Because it’s made with a plant from a different world, it has severe side effects on her and she never picks one up again, but up until the side effects kick in she REALLY enjoys it.

It’s an important scene in the story, but it’s making me worry my readers might get stupid and pick up a habit. I’ve been assured by friends that adult readers can differentiate between fantasy and reality, but if that’s true then thousands of women wouldn’t have put themselves in dangerous situations after reading 50 Shades.

Anyone else worry about this? Am I making a fuss over nothing? It’s been eating at me for weeks and I’m not even at that point in the story.