On marriage and stress

Several studies have suggested that married people are healthier than those who are single, divorced or widowed. What we have for the first time in a report from Carnegie Mellon University is the first biological evidence that serves to explain how marriage impacts health. Published in Psychoneuroendocrinology, the study noted that people who are married individuals have lower levels of the stress hormone cortisol than individuals who never married or were previously married. These findings underline the commonly held belief that people who aren't married face more psychological stress those who are married. It is well-known that prolonged exposure to stress is associated with increased levels of cortisol  - and this interferes with the body's ability to regulate inflammation. Poorly controlled inflammatory processes promote the development and progression of many diseases.

The investigators feel that they may have uncovered a physiological pathway that will explain how relationships influence health and disease. The study, which was conducted in 572 healthy adults aged between 21 and 55 years, looked at the 24 hr profile of cortisol in saliva samples collected on three non-consecutive days. The data showed that married participants had lower cortisol levels across the 3-day period than those who were never married or previously married people. The researchers also compared the daily change the cortisol profile - typically, the levels of cortisol peak at waking and declines during the day. Those who were married showed more rapid declines in cortisol, a pattern that has been associated with a lower risk of heart disease and longer survival among cancer patients.