Will a hug a day keep the doctor away?

You'll get no argument from most people — especially on a cold winter's night — that hugs make you feel warm inside.

But can that good feeling protect your health? Increasingly, scientists are thinking that the answer is yes.

Over the past decade, researchers have sought to explain the positive effects credited to the nonverbal gesture of human connection. Meanwhile, other research has linked chronic stress to shorter life spans, higher rates of heart disease and diabetes, depression and less effective immune systems.

New research ties hugging to both tracks: hugs as a method of social support, buffering the body from stress, and hugs as a physiological experience that lowers blood pressure and levels of the stress hormone cortisol.

Psychologist Sheldon Cohen of Carnegie Mellon University led research that found that people who experience high levels of social support and frequent hugs were protected from a higher risk of getting sick when under stress.

In the study, published in Psychological Science, healthy volunteers agreed to be exposed to people suffering from colds or flu and then were monitored for 14 days. Overall, the volunteers who received frequent hugs stayed healthier than the non-huggers.

A quick disclaimer from Cohen: This does not necessarily mean that we should hug more during the cold and flu season.

"Our studies are different than the real world," he said. "We control for the exposure to the virus. In the real world, there is no controlling exposure. If you're giving hugs during the flu season, you're increasing your exposure."

Since the mid-1980s, research by Cohen and others reported on the ways a social network can help a person cope with life's stressful events, including interpersonal conflicts. By 1999, research found that people who had stress from conflict with other people and were exposed to the common cold virus had a higher risk of being infected.

The first part of the latest study was begun in 2000.

"Our interest has been historically in social support," said Cohen. "Our lab and others have developed a lot of evidence that in people who have strong social support networks, their network will buffer them from the effects of stress. Less known is how that happens, how social support is conferred to people."

Showing support

In the past, he explained, the amount of social support for a person has been measured by asking people what support they have, not in what people do to show this support. In the recent study, hugs were considered markers of close interpersonal relationships.

"In times of stress and conflict, that's when support from people in your life is important," Cohen said. "It may make less difference in other times in your life."

"Overall, other studies about nonsexual touch [have found] it can buffer acute physiological markers of stress," he said. "We wondered if it would work in the real world."

In the case of the volunteers exposed to germs, participants with low levels of social support and more frequent interpersonal tension and conflict were found to have a greater likelihood of being infected. Social support and hugs seemed to offset the negative effect of tension and conflict in being susceptible to getting sick.

"If you have high levels of conflict, you're more likely to get infected," Cohen said, "but you're protected from that if you have either high levels of social support or high levels of hugs."