Bad feelings may spur chronic inflammation, study suggests

Ten years of frequent hostility and depression may harm men's immune systems and put them at risk for heart disease, a U.S. study found. These negative emotional states may also hike men's risks for related disorders such as type 2 diabetes and high blood pressure, according to research in the August issue of Brain, Behavior, and Immunity.

Angry men are more likely to have increased levels of C3, an immune system protein associated with chronic inflammation, say the researchers from Duke University.

"Hostile, depressed and angry people see the world around them in a different way, and sometimes they see it as them against the world," study co-author Edward Suarez said in a prepared statement. "That kind of lifestyle often leads to greater stress and possibly changes in the way the body functions that could lead to disease."

Other research has shown a relationship between elevated levels of C3 and chronic diseases such as heart disease and diabetes.
The Duke team studied 313 male Vietnam veterans over a 10-year period. The men were part of a larger study on the effects of the wartime defoliant Agent Orange. All of the men underwent standard psychological testing to assess hostility, depression and anger. The researchers also tested the men's blood on three occasions between 1992 and 2002.

The researchers looked for changes in levels of C3 and C4, immune system proteins that are markers of inflammation, the body's response to injury or infection. Men whose psychological screening showed the highest level of hostility, depressive symptoms and anger had a 7.1 percent increase in C3 levels, the investigators found, while men with low scores on the test showed no change in C3 or C4 over the decade. Levels of C4 did not change for either group.

The relationship between the psychological scores and C3 levels remained true even when the researchers looked for the possible effects of other risk factors. Smoking, age, race, alcohol use, body mass index and Agent Orange exposure had no influence on C3 levels. The researchers noted that while the study does not point to psychological therapy as a means of preventing inflammation, finding ways to reduce anger and hostility couldn't hurt.