How Stress Harms the Heart

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Roy Morsch / Corbis

Researchers have long suspected that stress does the body harm, but bulletproof clinical evidence linking stress to heart attacks and other disease has been elusive — partly because stress is such a personal and variable thing. Only recently have such studies started to gather critical mass, and researchers have begun calling on clinicians to include the diagnosis and treatment of stress in the routine care for patients with conditions like AIDS and heart disease. "Every layman knows that stress is a cause of heart disease," says Dr. Kristina Orth-Gomer, who has been studying stress and cardiology for 25 years, and now works at Stockholm's Karolinksa Institute. But she feels that physicians have been slow to put that knowledge into practice. "Lately, that is beginning to change. The evidence is more convincing now," she says.

Two studies published this week in the Journal of the American Medical Association (JAMA) and the Archives of Internal Medicine lend support to her cause. The JAMA study, led by researchers at the Université Laval in Quebec, finds that first-time heart attack patients who returned to chronically stressful jobs were twice as likely to have a second attack as patients whose occupations were relatively stress-free. The study tracked 972 first-time heart attack survivors, aged 35-59, all of whom went back to work within 18 months of their heart attack for at least 10 hours a week. In periodic follow-up interviews between 1996 and 2005, those patients who reported chronic job strain — defined as a job that was high in psychological demands but low in feelings of control — were not only at higher risk for a second heart attack, but also had a markedly higher risk of death than their less-stressed peers. Studies like this may strengthen the link between stress and disease, says Orth-Gomer, whose editorial accompanies the Canadian study in the October 10 issue of the journal, but, she says, it's only a beginning: "The other argument is, of course, what do you do about it?"

One solution: Find practical ways for doctors and nurses to screen and help treat the kinds of stress — professional and personal —that put their patients at risk. Right now, it isn't part of standardized practice for cardiologists, for instance, to evaluate their patients' feelings about a taxing job or a difficult marriage. But doctors should be asking these questions, says Orth-Gomer, and it's incumbent upon the medical community to make them part of routine care.

Joining her call for intervention is Sheldon Cohen, a psychology professor at Carnegie Mellon University and author of a commentary, which also appears in the current issue of JAMA and examines the effects of psychological stress on a variety of major diseases. Cohen's review of past studies finds that stress — particularly "social stressors" like divorce and the death of a loved one — often triggers clinical depression or worsens it, and causes relapses in people who have recovered. The report also suggests that stress may quicken the progress of the disease in AIDS patients, and, like the Canadian study, finds that chronic stress exacerbates heart disease. "There is a fair amount of evidence that the relationship [between stress and disease] exists — enough to start asking whether reductions of stress would reduce disease outcomes," says Cohen, adding, "People have not been asking [this] question."

The problem is that many doctors don't have the time to ask. Highly specialized physicians like cardiologists and oncologists are busy, and few of them have time for long, leisurely doctor-patient conversations. "It's ironic that as we're getting a broader picture of how important stress levels are to physical health, we're simultaneously cramming appointments into shorter and shorter periods of time," says Dr. Daniel Brotman, director of the Hospitalist Program at Johns Hopkins Hospital and author of a review paper on emotional stress and heart health, which was published in the September issue of The Lancet. Brotman acknowledges the strong link between stress and cardiovascular disease, but he doesn't think it's realistic to ask doctors to screen every patient for stress. "We say to ourselves as physicians, 'Well, there's not a lot I can do about the fact that your wife left you,'" he says. "So much of what we face in our lives is stress that we can't do a whole lot about."

What can be changed, however, is the way doctors listen to their patients' health concerns. If a woman complains of chest pain, for example, but says it only bothers her when she's feeling "worked up" — but not on the treadmill or climbing a flight of stairs — her physician should interpret her emotional state as a real, physical risk factor, says Brotman. "The trigger is emotional, and physicians tend to blow that off," he says. "Traditional Western medicine has really endeavored to think of the body as a machine, and disease as how the machine breaks down. [Doctors can be] reluctant to think of the mind and body as being part of that same machine."

There are a number of ways that stress can recalibrate our physical machinery. For starters, stressed-out people tend to neglect their health in general — they eat poorly, sleep badly, don't exercise and smoke and drink too much — behaviors that don't exactly promote well-being. Stress also triggers the body's endocrine systems, prompting the release of hormones that play out in the body in a variety of ways: they might, for instance, irritate lymphatic tissue that in turn alters our immune functions, or they might simply cause the resting heart to beat faster. "Anybody who has almost been hit by a bus knows how much emotional stress can rev up your cardiovascular system," says Brotman. "But having frequent bouts of fight or flight is not something we're designed to do." That's where chronic stressors become physical threats.

And, still, many patients fail to acknowledge that those threats exist. For some, admitting to stress feels like a sign of weakness; others resign themselves to it, as if it were an unavoidable dimension of life. So most of us simply carry on with our 15-hour workdays and fraught relationships. In another study published in the October 8 issue of the Archives of Internal Medicine, researchers at the University College of London followed a group of about 9,000 civil servants for 12 years and found that people who experienced negative close relationships — marked by conflict and fighting — had a 34% higher risk of a coronary event than those with low levels of negativity in their closest personal relationships. The emotions that play out in a bad marriage for instance, the authors write, have a direct, cumulative "wear and tear" on organs and tissues that may leave people at greater risk of illness.

A stressful job or a bad relationship may not send all of us into depression or to the ER — statistically speaking, most of us weather the stresses of life just fine — but for now it's impossible for doctors to predict who will be susceptible and who won't. So, whether it's a matter of quality of life, or life and death, it's probably good advice for the stressed-out folk among us to take a breather now and again. "With chronic stress, we may not feel it in our cardiovascular systems, but we do feel drained," says Brotman. "It's hard to imagine going through those periods and not thinking, 'This has got to be bad for me.'"