In a 2010 study, researchers invited nearly 2,000 Canadians into the lab to talk about their anger and stress at work. Observers rated them on a scale of one to five for the extent to which they expressed positive emotions like joy, happiness, excitement, enthusiasm, and contentment.
Ten years later, the researchers checked in with the participants to see how they were doing—and it turned out that the happier ones were less likely to have developed coronary heart disease.
In fact, for each one-point increase in positive emotions they had expressed, their heart disease risk was 22 percent lower.
Source: Six Ways Happiness Is Good for Your Health By Kira M. Newman | July 28, 2015