don't worry, be healthy

[F]ear causes stress, and stress is bad for your health. Numerous studies have shown the familiar link. The American Heart Association has emphasized a correlation between stress and overeating and stress and smoking, both of which lead to heart disease. A 2000 study in the journal Stroke of more than 2,000 men showed that those suffering from anxiety or depression were three times as likely to suffer a fatal stroke. A study in Psychosomatic Medicine showed that Israeli women with an expressed fear of terrorism had twice the level of an enzyme that correlates with heart disease.
   - from Slate