How is smoking related to ulcerative colitis (UC)?

You would think smoking is a risk factor for ulcerative colitis, but actually the opposite seems to be true. Experts aren't sure why, but it seems that tobacco use (and actually not just in cigarettes, but otherwise), may actually provide some protection against developing ulcerative colitis. In fact, people who've given up smoking are 1.7 times more likely to develop UC.

However, given all the other health dangers smoking leads to, preventing UC is hardly a good reason to maintain the habit if you're able to quit. Besides, smokers still make up about 40 percent of the population with ulcerative colitis.