From Scientific American:
You probably think you’re doing everything you can to stay healthy: you get lots of sleep, exercise regularly and try to avoid fried foods. But you may be forgetting one important thing. Relax! Stress has a bigger impact on your health than you might realize, according to research presented yesterday at the annual conference of the American Psychological Association in Boston.
Ohio State University psychologist Janice Kiecolt-Glaser and her partner, Ronald Glaser, an OSU virologist and immunologist, have spent 20-odd years researching how stress affects the immune system, and they have made some startling discoveries. An easy example comes from their work with caregivers, people who look after chronically ailing spouses or parents (no one would argue that this role is quite stressful). In one experiment, Kiecolt-Glaser and her colleagues administered flu vaccines to caregivers and control subjects and compared the numbers of antibodies—proteins involved in immune reactions—that the two groups produced in response. Only 38 percent of the caregivers produced what is considered an adequate antibody response compared to 66 percent of their relaxed counterparts, suggesting that the caregivers’ immune systems weren’t doing their jobs very well—and that the stress of caregiving ultimately put them at an increased risk of infection.
More here.