THURSDAY, May 23, 2002 (HealthDayNews) -- To paraphrase the character Tevye from "Fiddler on the Roof" as he argues with God: "On the one hand..."
This is precisely what has happened with two new studies that seem to conflict with each other over the long-held notion that stress causes heart disease.
First, the "contradictory" study:
Researchers publishing in the May 25 issue of the British Medical Journal conclude that previous studies showing a relationship between psychological stress and heart disease may have been biased because they relied on participants' own perceptions.
The middle-aged Scottish men in this 20-year-long study who complained more of stress also complained more of symptoms (especially angina) and were admitted to the hospital more often. At first glance, this might appear to indicate that the stressed-out men had more heart problems. But it wasn't a scientific fact. The men simply reported more symptoms and visited healthcare facilities more often.
However, men who went into the hospital with heart attacks or who ended up dying (both considered to be more objective criteria, of course) did not exhibit a higher level of stress.
The prevalence and incidence of ischemia or restricted blood flow -- another serious condition -- were inversely related to the incidence of perceived stress.
This study is also unusual because it found the highest levels of stress among men who were socio-economically advantaged. In many other studies, the most stressed-out individuals were those at the bottom of the socio-economic scale, making it difficult to identify whether their heart disease was caused by stress or some aspect of the way they lived.
Even though the stressed men in this study tended to smoke more, drink more and exercise less, they were still healthier than their calmer counterparts.
But this doesn't mean that stress protects against heart disease either.
"Most stressed men were socio-economically advantaged. Their socio-economic advantage appeared to offset their unhealthier lifestyles," says Dr. John Macleod, lead author of the study and a clinical research fellow at the University of Birmingham in the United Kingdom. "Hence, in this population, it seemed that though smoking, drinking, not exercising etc. were bad for your health, socio-economic disadvantage appeared worse."
Now, on the other hand ... the second study, published in the May issue of Psychosomatic Medicine, outlines a definite pathway leading from psychological distress to coronary disease. Chronic stress is associated with psychological distress, which can manifest itself in poor social supports and coping skills. The psychological distress leads to poor health habits: not enough exercise and a poor diet. This leads to changes in body composition and metabolism that eventually lead to heart disease.
Macleod says this theory is plausible, but it doesn't necessarily imply a cause-and-effect relationship.
"In our study, higher stress was indeed associated with unhealthy behavior," he says.
"Despite this, it showed no association with objective health, probably indicating the primacy of material conditions in determining health," he adds. "In simple terms, smoking is certainly bad for you, but being poor is worse."
But don't discount the role of stress just yet, warns Dr. Stephen Siegel, clinical assistant professor of medicine at New York University School of Medicine in New York City. There have been plenty of studies that have measured stress levels objectively, and besides, the participants in Macleod's study were quite young and may not have manifested any disease yet, he adds.
Siegel continues to take stress seriously. "I think that as a cautious health-care provider, we have to assume that there is some relationship and try and deal with it because the evidence at least is suggestive and it would be foolish to ignore it," he says.
What can you do?
"The bottom line for the general public is that you shouldn't get stressed about being stressed. But . . . we should all try to reassess the things we do," Siegel says. "I don't know if we can really change our personality type, but we can control our behaviors so we can control cigarette smoking or exercise and avoiding fatty foods which helps reduce stress. All of those are basic, well-documented factors."
What to Do: For more information on stress and its impact on heart disease, visit the American Heart Association
