To investigate, Boyle and his team looked at
levels of two inflammation markers, C3 and C4,
in 313 men, who were an average of 50 years old,
participating in the Air Force Health Study, a
long-term investigation of the effects of Agent
Orange. They assessed the men's level of
hostility, anger and depression in 1985 and
measured their C3 and C4 levels in 1992, 1997
and 2002.
Men with the highest levels of
anger, depression and hostility also showed the
greatest increase in C3 levels between 1992 and
2002, the researchers found. But there was no
association between these psychological factors
and levels of
C4.
Research has linked higher levels of C3 to a
greater risk of heart disease, abnormal heart
rhythms and diabetes, Boyle and his team point
out. They believe these findings provide
additional support to the hypothesis that
emotional factors contribute to health problems
by influencing levels of chronic inflammation.
In an interview, Boyle pointed out that the
assessment for hostility, anger and depression
took place seven years before measurements of C3
and C4 began, and that all study participants
were "very, very healthy," making it unlikely
that, for example, the men might be depressed
because of some underlying health problem that
could also boost C3 levels. "That gives us a lot
of confidence that these psychological factors
precede the increase in inflammation."
While most people who are depressed will want
to get treatment, Boyle noted, many individuals
with hostile personalities may not be aware of
it, and are thus unlikely to seek help.
However, there are definitely ways to lessen
the impact of personality on health, he added.
For example, he said, stress reduction
techniques are helpful. "Even if you get angry,
the consequences may be less severe if you're
able to calm down quicker or if you're able to
develop techniques to become angry less easily."
SOURCE: Brain, Behavior and Immunity, August
2007.
© Reuters 2007