A happy heart seems to do a body good
March 09, 2005
USA TODAY

Inflammation levels reduced

VANCOUVER, B.C. -- Good relationships and a sense of purpose may help women over age 60 fend off heart disease, arthritis and other illnesses by reducing the inflammation that promotes them, a new study says.

On the other hand, poor mental health such as depression, anxiety and hostility can increase the harmful inflammation, another study suggests. Both reports were released last week at the American Psychosomatic Society meeting here.

In the first study, the more positively women rated their relationships, the lower their levels of interleukin-6, a protein that is created by inflammation and also causes inflammation, says psychologist Elliot Friedman of the University of Wisconsin. And the more sense of purpose women feel, the fewer receptors their blood has for the damaging protein, he says.

Friedman studied 135 women ages 61 to 91 in relatively good health. After taking into account factors such as illness, medications and weight that could affect interleukin, he still found a strong link between a positive sense of well-being and lower levels of the harmful protein.

As adults age, their interleukin-6 rises, 'so if there's something we can do to bring it down, that's important to know,' he says. Happier women have lower levels of the stress hormone cortisol, and that could be tied to less of the protein.

Also, good relationships could improve sleep, and good sleep has been linked to less interleukin-6.

Both explanations are plausible, says Gregory Miller, a psychologist at the University of British Columbia who has studied depression and interleukin. 'If what he's suggesting is true, it would have hugely important implications for health,' Miller says.

But he says at least some of the inflammation could be a result of diseases that are common in older adults but haven't surfaced yet and so might be missed in studies. For example, heart attacks and strokes happen suddenly but can take years to develop. 'You might look healthy, but your arteries are smoldering, and there's less blood going to the brain, which could affect your well-being,' Miller says.

So happier, more purposeful people could be benefiting from less disease-caused inflammation rather than their well-being itself reducing the dangerous molecules. 'It's a chicken-or-egg question' that can be answered only by longer-term studies, Miller says.

On the negative side of mental health, a study tracking 331 healthy adults over three years found that initial high levels of depression, anxiety and hostility led to more interleukin-6 in three years. The more depressed, anxious and hostile a person was at the outset, the more the protein increased, says Jesse Stewart, a University of Utah psychologist.

Upset adults might produce more of the stress hormone cortisol. In the short term, cortisol lowers inflammation, but there's some evidence that chronically high levels make receptors for it less sensitive over time. Then they no longer take in the cortisol, so inflammation can run rampant.

Says Stewart: 'We're starting to understand how depression might get inside the body to influence cardiac health, and one way is promoting inflammation that causes heart attacks.'