Your husband or wife may not be stressing you out as much as you think.

A new study claims married people have overall lower levels of cortisol – often called the ‘stress hormone’. It regulates many changes in the body including blood sugar levels, immune responses and inflammation.

Past research has suggested that married people are healthier than those who are single, divorced or widowed.  And this study is the first to provide biological evidence explaining just how marriage impacts health.

The study, conducted at  Carnegie Mellon University, looked at saliva samples collected from over 500 healthy adults between ages 21 and 55 over a three-day period. Multiple samples were taken daily and tested for cortisol levels. Researchers found that the married participants had lower cortisol levels than the never married or previously married people across the three-day period. 

The team also compared each person’s daily cortisol rhythm. Typically, cortisol levels peak when a person wakes up and declines during the day. Those who were married showed a faster decline, a pattern that has been associated with a lowered risk of heart disease, and longer survival among cancer patients.

Increased cortisol levels are linked to prolonged stress and can disrupt the body’s ability to control inflammation. Previous studies have suggested that marriage may be associated with lower cortisol levels because most married people are relatively satisfied with their marriages.

The researchers suggested that the lower levels of cortisol in married people could also be related to better access to healthcare due to the availability of insurance and more economic support.

Elderly men were 50 percent less likely to fracture a hip if they were married, while elderly married women cut their risk by 30 percent. Experts suggested a possible reason was that seniors who live with their partner are less likely to be malnourished or depressed, making them less frail.