As the title says....health niche are still good for adsense.But the important thing is you have to be very careful on choosing which sub-niche of the health niche will work.Just check the trends in google and if you want to know an approximate cost of adsense clicks... you can check out spyfu.com . It gives a view of the price of each word (it gives a good view of the adwords price).I have been using all these information and have built my chemotherapy site... Its just ten days old and now making 1$ a day...Though it is not a big amount,I believe that I can build on it....I just get 1 click a day...and that gives me 1$...So If I target on getting more traffic,I am sure to make some good money out of it....So try health niche....and produce quality sites and earn from adsense