they are healthy because they are happy...

Happiness Is the Best Medicine
(As published in Wired, by Rowan Hooper, 04.18.05)

The pursuit of it was written into the Declaration of Independence, but finding the causes and effects of that elusive "it" -- happiness -- has been notoriously difficult.

Whatever brings you happiness, be it large breasts, lots of money, respect from your peers, a large bar of chocolate or even semen, it's hardly controversial to say that happy people are generally healthier than unhappy ones. That conclusion might be intuitively obvious, but just why are happy people healthier?

That's what researchers at University College London's Department of Epidemiology and Public Health are interested in. They have found that the functioning of certain key biological processes is improved by happiness.

"Psychosocial factors are vital to health," said Michael Marmot, professor of epidemiology and public health at the university and director of the International Centre for Health and Society. "In people who have their basic needs met -- clean water, sufficient food and shelter -- a crucial determinant of health is how circumstances affect the mind. That is, psychosocial factors."

Other studies have shown a connection between happiness and longevity. In 2001, Deborah Danner, at the University of Kentucky's Center for Gerontology, analyzed the handwritten autobiographies of 180 nuns of mean age 22, and compared the positive emotional content of the writings with the nuns' health six decades later. It turns out that sisters who used words like "joy" and "thankful" lived up to 10 years longer than did those who expressed negative emotions.

Marmot and colleagues, including health psychologist Andrew Steptoe, wanted to know what causes these differences. What is the mechanism that helps happy people live longer?

To find out, they studied the emotions and health of more than 200 middle-aged Londoners in their daily lives. They found that people who reported that they were pretty much happy every day were verifiably healthier. Happiness is associated with reduced neuroendocrine, inflammatory and cardiovascular activity. Their work is published this week in the journal Proceedings of the National Academy of Science.

To investigate the psychobiological connection, the UCL scientists put their volunteers -- men and women of white European origin aged 45-59 -- through laboratory stress tests and monitored their blood pressure and heart rate over a working day. Saliva samples were taken to measure the volunteers' cortisol content. Cortisol is a stress hormone related to conditions such as type II diabetes and hypertension.

"Cortisol is a key hormone," said Steptoe, "because it has an impact on so may different physical conditions."

The results were clear-cut. There was a 32 percent difference in cortisol levels between the least and the most happy subjects. Happy subjects also showed lower responses to stress in plasma fibrinogen levels, a protein that in high concentrations often signals future problems with coronary heart disease. Finally, happy men had lower heart rates over the day and evening, which suggests good cardiovascular health.

In addition to screening for happiness, Steptoe and colleagues also used an established method to measure psychiatric disorders that are known to predict coronary heart disease. So they were able to control for psychological distress -- and they found that health-related biological factors were independently related to happiness. In other words, people aren't just happy because they are healthy, they are healthy because they are happy.

It's all good news for comedians. Laughter is good for you -- it's practically official. Last month researchers at the University of Maryland School of Medicine in Baltimore showed that laughter is linked to the healthy function of blood vessels.

The researchers showed volunteers funny or stressful segments of movies and found that those that provoked laughter apparently caused the tissue that forms the inner lining of blood vessels, the endothelium, to dilate to increase blood flow.

Spirituality and religion, too, seem to be somehow beneficial to health. Last week at the American Academy of Neurology meeting in Miami Beach, Florida, Yakir Kaufman, director of neurology services at Sarah Herzog Memorial Hospital in Jerusalem, presented results suggesting that spirituality and the practice of religion may help slow the progression of Alzheimer's disease.

"We learned that the patients with higher levels of spirituality or higher levels of religiosity may have a significantly slower progression of cognitive decline," said Kaufman.

The new work may help to demystify the effect of spirituality or religion.

"There is some evidence that religious beliefs help people cope with the stresses and strains of life," said Steptoe, "so this could be linked with the same processes that we have studied."

Marmot concurred. "Our research shows that psychological processes have profound biological effects," he said. "Spirituality can be one example of how the brain, acting through its connections with the neuroendocrine system, can have important effects."