Friends make our lives better. They help us laugh, stand by us when we’re down and they're always up for a night on the town or an afternoon on the hiking trail. But it turns out that friends are good for a whole lot more. In fact, researchers have amassed an impressive list of benefits. Not only do our buddies enhance our psychological stamina, but they also make us physically stronger, mentally sharper and more successful. Here are several science-backed ways that friendships help us shine.

1. Friends make you healthier.

Sure, you should exercise, eat right and adopt all the traditional "good for you" health habits. But don’t forget to add socializing to the list. Turns out that surrounding yourself with good friends is an important way to stay healthy throughout your life. It's not surprising, since humans are wired to be communal — in fact, we’ve survived and thrived for eons by banding together in social groups — but good to remember.

A recent study from the University of North Carolina at Chapel Hill found that people of any age without strong connections to others have significantly higher blood pressure, abdominal obesity rates, and circulating levels of C-reactive protein (a measure of inflammation in the body) — all of which leads to chronic and deadly conditions such as heart disease, cancer and arthritis. This lends support to many studies showing that solid social ties make your body more robust, including strengthening your immune system, reducing your risk of infections like colds, keeping your heart healthy and cutting your risk of stroke.

2. Companions help you live longer.

Researchers at Brigham Young University analyzed nearly 150 studies focused on the link between social bonds and mortality. Their stunning conclusion? Whatever your age, if you’re surrounded by friends and family, your chances of dying for any reason drop by 50 percent. Or consider it from another perspective: loneliness is a killer — equivalent to deadly habits like smoking and more detrimental than being obese or not exercising. The researchers surmised that those who feel bonded to a group and responsible for others are more likely to take care of themselves and avoid unnecessary risks. A 10-year Australian study showed similar longevity findings among older people: Participants with the largest number of friends outlived those with the smallest number by 22 percent. Just one more reason to include social time to your daily health and fitness regimen.

two young black girls share a laugh together The bonds of friendship are good for your body and mind, enhancing your health, happiness and longevity. (Photo: Cornelia Viljoen/Shutterstock)

3. If you’re already ill, social bonds cut your chances of getting worse or dying.

Just as friendships help ward off disease, they also boost your likelihood of surviving a life-threatening ailment. For instance, researchers at Kaiser Permanente found that socially isolated women who were diagnosed with early-stage breast cancer were 34 percent more likely to die of their disease or other causes than patients with tight social ties. The same goes for heart-attack survivors. In one study published in the Journal of the American Heart Association, patients were found to have a lower level of mental function, worse quality of life and be more depressed a year after their heart attack than patients with broad social support. Likewise, kidney disease patients on dialysis who didn’t have a sound social network were more likely to ignore their doctors’ recommendations, experienced a lower quality of life and were more likely to die prematurely, according to research in the Clinical Journal of the American Society of Nephrology.

4. Socializing heightens the quality of your ZZZs.

That’s right, the more you pal around with others, the better your slumber. Researchers at the University of Chicago found that people who feel socially isolated and left out may sleep as long as social butterflies but are more restless in bed and snooze less soundly. In fact, for every unit of increase on the loneliness scale. participants experienced an 8 percent boost in restlessness during sleep. The takeaway: As social animals we sleep better when we feel secure in our relationships.

5. Buddies boost your brainpower.

Hanging out with others — even for 10 minutes — improves your brain function and ability to solve problems, according to a University of Michigan study. Conversely, lack of friend time can be bad for your brain, even accelerating cognitive decline as you age. One Swedish study found that older people without dementia who didn’t have good social support were at 60 percent higher risk for developing dementia during the three years of the study. Another study in the Netherlands suggests that just the feeling of being socially isolated can also affect dementia risk. Of the nearly 2,200 older people without dementia who participated, those who reported feeling lonely (whether or not they were actually alone) were 1.64 times more likely to develop dementia during the three-year study than those who felt socially connected.

silhouette of friends jumping for joy Having friends boosts your ability to roll with life’s punches and achieve your dreams. (Photo: Imaake/Shutterstock)

6. Friendship enhances your emotional resilience.

Intuitively, it seems obvious that sharing good times and bad with a network of friends boosts psychological well-being, helps you navigate life’s ups and downs, reduces stress, improves your sense of optimism and diminishes your chances of suffering a mental illness. Science also bears this out. Studies show that having a community of chums gives you a sense of belonging and raises your feelings of security and self-worth, which, in turn, buttresses psychological fortitude and dampens your body’s response to emotional distress. A 2007 study published in the journal Psychiatry showed that ties to others lower the negative neurochemical impacts of chronic stress, including the release of stress hormones and activation of the nervous system’s fight-or-flight reaction. Evidence also supports the idea that loneliness is linked to mental illness. Research in the Journal of the National Medical Association, found that visitors to a free health clinic who felt most alone were more likely to suffer from mental disorders like anxiety and depression.

7. A strong social circle helps you achieve your goals.

Whether you want to drop a few pounds or nab a promotion at work, surrounding yourself with supportive friends who have similar goals can help you reach your dreams. It isn’t just that they cheer you on or boost your resolve; it’s also that humans tend to mimic their friends and are swayed by the habits and preferences of their social group. Monkey see, monkey do.

For instance, studies show that people are typically similar to their friends in the weight department. If your friends are thin, you’re likely to be as well. Unfortunately, the reverse is also true. Likewise, hanging out with pals who eat healthy foods influences you to make better nutrition choices, and working out with someone who’s fit pushes you to run, stretch or pump harder yourself. Friends also influence your GPA. One UCLA study showed that kids who have lots of friends at school — sharing classes, school activities and focus on academics — are more likely to get good grades. Having a strong social network at work also boosts your job performance and productivity, according to a 2011 study by professors from the Wharton School of Business and California State University. Bottom line: choose your friends wisely and surround yourself with people who inspire you.

Learn more in this TEDx talk by neuroscientist John Cacioppo, who emphasizes how social humans are and why friendships — or more importantly, a lack of them — affects our mental and physical health.