The Health Power of Friends

Researchers who study friendship have uncovered many of its health benefits. Here's how friendship can be good for you.

1. FRIEND MAY EXTEND YOUR LIFE

Having good friends may help you live longer. In fact, according to a 2010 review of research, the effect of social ties on life span is twice as strong as that of exercising, and equivalent to that of quitting smoking.

2. BUDDY UP FOR GENERAL GOOD HEALTH

Research found that poor  measures of health were worse in people who also had weaker social ties, reporting their work in January 2015 in the journal Proceedings of the National Academy of Sciences. For example, among the people in the study who were in old age, a lack of social connections more than doubled the risk of high blood pressure (raising it by 124 percent). For comparison, having diabetes raised the risk of high blood pressure by much less (70 percent).

3. FRIENDSHIPS MIGHT HELP KEEP YOUR MENTAL HEALTH SHARP

Friends can improve your cognitive ability. Having friends who make you feel like you belong may be a key for better physical health. A 2012 study found that older people's dementia risk increased with their feelings of loneliness. The study followed more than 2,000 residents of the Netherlands ages 65 or older over three years. None of the participants had dementia at the beginning of the research, but 13.4 percent of those who said they felt lonely at the start of the study developed dementia during the study period, compared with 5.7 percent who didn't feel lonely. [10 Ways to Keep Your Mind Sharp ] "The fact that 'feeling lonely' rather than 'being alone' was associated with dementia onset suggests that it is not the objective situation, but rather the perceived absence of social attachments that increases the risk of cognitive decline," the researchers wrote in their findings, published in the Journal of Neurology, Neurosurgery and Psychiatry. (However, the study found an association, and couldn't determine whether the loneliness was a cause of  the dementia.)

4. FRIENDS INFLUENCE US IN GOOD WAYS AND BAD

There was a headline that said Obesity is contagious, after a 2007 study that found that when one person packed on extra pounds, his or her friends were more likely to become obese, too. But there was an overlooked bright side to the research, which appeared in the New England Journal of Medicine. Lean, healthy lifestyles spread like social wildfire, too. The researchers pulled data from a large health study, the Framingham Heart Study. It followed people over time, allowing researchers to draw causal inferences. If one person became obese over the course of the study, they found that friends of that person were 57 percent more likely to become obese, too. [8 Reasons Our Waistlines Are Expanding]

5. ‘SOMEBODY TO LEAN ON' 

We all need somebody to lean on, as the song goes. And research on cancer patients finds that when the going gets tough, friends can help. A major study published in the journal The Lancet in 1989 found that women with breast cancer who were randomly assigned to attend support groups with other cancer patients reported better quality of life and lived longer, compared with women in a control group who were not assigned to such support groups.

6. FRIENDSHIPS CAN LAST A LIFETIME

Facebook isn’t a person with a human heart and connection. In an era when people move around a lot for school and jobs, maintaining friendships can be difficult.  However, research finds that distance doesn't have to break up a friendship. In one study, researchers followed college friends beginning in 1983, asking them about their friendship.. They found that physical distance didn't necessarily track with the emotional closeness of a friendship over decades. Phones and email still kept friends in touch two decades later, the researchers found, especially those who had been friends longer in college and those who had similar interests when they became friends.