It's official, happiness is good for health!

A new UK study suggests that people who are happier in their daily lives have healthier levels of key body chemicals than those who muster few positive feelings.

A new study conducted by researchers at University College London, UK suggests that people who are happier in their daily lives have healthier levels of key body chemicals than those who muster few positive feelings.

"This study showed that whether people are happy or less happy in their everyday lives appears to have important effects on the markers of biological function known to be associated with disease. Perhaps laughter is the best medicine," lead researcher Jane Wardle said.

The team studied 216 middle-aged men and women living in London, UK, who are part of the ongoing "Whitehall II" study of thousands of civil servants, led by Michael Marmot.

They were asked to rate how happy they had been feeling in the last five minutes at about 33 points during their working or leisure days and their heart rates and blood pressures were also measured by an automated system.

Saliva samples were also taken from the volunteers at eight points during a working day and a leisure day to test levels of the stress hormone cortisol. On one occasion, the subjects were invited into the lab and given a "mildly stressful" task to perform while their biological responses were measured.

The team controlled for factors such as socioeconomic position, age and gender to try to tease out the effects of happiness alone on health. "The happier you were, the lower your cortisol levels during the day. For men, but not for women, the happier you were the lower your average heart rate was, " Wardle added.