A new study suggests that marital bliss has beneficial health effects. The research is from Carnegie Mellon University in the USA. It concludes that being married reduces your levels of a stress hormone called cortisol. Researchers tested for cortisol in the saliva of 572 adults aged 21-55 on three different, non-consecutive days. Multiple saliva samples were taken throughout each 24-hour period. The researchers found that the married people in the sample had less cortisol than people who were single, separated, divorced or widowed. The researchers said: "Married people tend to be healthier than both the previously and never married, but the mechanisms through which this occurs remain unclear."

The stress hormone cortisol has many different functions in our body. It regulates blood sugar levels, immune responses and inflammation and can increase the risk of heart disease. It also increases the chances of surviving cancer. High levels of cortisol have been linked to mental conditions such as anxiety and depression. Laboratory director Sheldon Cohen said: "These data provide important insights into the way in which our intimate social relationships can get under the skin to influence our health." Researcher Brian Chin added: "It is exciting to discover a physiological pathway that may explain how relationships influence health and disease."