I believe you’re asking if health companies purchase the data. So I’ll make the assumption that maybe you’re a smoker and you’re wondering if your data will be purchased that you smoke and participate in smoking communities.
The official answer is no, and I doubt they are specifically purchasing that.
However, I think this is going to get very muddy very quickly over the next few years, as I don’t believe there are any laws (in the US) protecting us from health companies purchasing that info. At this point it’s been fairly difficult, but with machine learning and generative AI it’s going to be relatively simple to say “From all of the information you have about {user} tell me if they are a smoker, and if so how long they have been smoking” and then code to say if true and greater than 5 then put them in a higher insurance bracket.
So, I guess I’ll say probably not, but I wouldn’t risk it if you’re real worried.