Hold on to that BFF! Studies show that a strong friendship comes with a plethora of physical, emotional, and mental health benefits

By Kaitlin Menza
June 19, 2015

Chances are, you're already clued in to some of the ways your best friends affect your mental state. When your BFF sends you an adorable puppy video, your mood instantly rises. When you're having a horrible work day, your p.m. margarita plan with your pals is the only motivation you need to get through it. Friends celebrate you when you're happy and boost you up when you're sad. There's no understating the happy influence they have on your emotions. (In fact, calling a friend is one of the 20 Ways to Get Happy (Almost) Instantly!)

That influence is even bigger than you might realize. Scientists and experts are constantly uncovering the benefits of solid friendships for your blood pressure, your waist line, your willpower, your life span, even your likelihood of breast cancer. Read on to get a small taste of how much your friends are helping you out-and consider sending a thank-you note to all those wonderful people in your life. They're saving you from some serious medical bills.

She Helps You Eat Better


Corbis Images

You sit down to dinner and your friend orders a salad. Suddenly, it seems slightly gross to indulge in the heavy, creamy pasta you were previously planning on. That vague peer pressure can be a good thing, if it leads to healthier choices. A study in Social Influence analyzed 38 different studies on "social modeling" when dining, or the way in which we imitate the people we're eating with. If you're trying to keep it light yourself, sharing a meal with, say, Gwyneth Paltrow (or your healthiest BFF) will easily strengthen your willpower.

She Makes Working Out More Fun


Corbis Images

Signing up for a class with a friend doesn't just hold you accountable to showing up, or push you to try a little harder to impress her. Sure, those are nice advantages, but you're not imagining it: Your friends make fitness more fun. In a study, participants enjoyed their workouts more alongside a friend. (Learn Why Having a Fitness Buddy Is the Best Thing Ever.)

She Helps You Through the Work Day.


Corbis Images

When your work wife goes on vacation for a week, you suddenly realize how brutal the 9-5 is without her. A Gallup poll showed that close friendships in the workplace lift employee satisfaction by 50 percent, and people with a bestie in the office are seven times more likely to engage deeply in their work. Permission to tell your boss that weekly happy hours are good for your bottom line granted.

She Helps You Live Longer


Corbis Images

A landmark Australian study of elderly people over the course of 10 years revealed that those with strong friendships were 22 percent less likely to die. Play your friendship cards right, and your clique could wind up hitting the early-bird special together until you hit triple digit status.

She Changes How You Experience Stress


Corbis Images

The fight-or-flight response to stress may be one of the few things you remember from biology class in high school. But a UCLA study suggests that women have a more nuanced hormonal reaction than that (cue the duhs). Scientists found that when oxytocin was introduced during a stressful situation, women could soothe the need to fight or flight, while men could not. If you added more women into the stressful situation, even more oxytocin was produced in the female participants-and again, not so much in men. So not only do women deal with stress differently, they feel better when other women are around. Seriously.

She Stops Cancer Cells from Growing in Your Breasts


Corbis Images

Scientists have gone back and forth about the tangible results of friendships or group therapy for cancer patients. But a truly fascinating study of a small group of women in Chicago found that the release of cortisol due to the stress of social isolation assisted in the growth of breast-tumor cells. Loneliness literally accelerated their cancer.

She Protects You from Depression


Corbis Images

In a Canadian study, 10-year-old girls with a genetic predisposition to depression were less likely to have the mental illness manifest if they had a minimum of one close friend. The relationship seemed to literally protect them from harm. Turns out your childhood buddy was a superhero!

She Keeps You from Overspending


Corbis Images

The concept of retail therapy isn't just something advertisers came up with to make you feel better about shopping. It turns out you're more likely to take major financial risks when you're feeling lonely or rejected-like when you buy a flight to Paris to soothe your soul after a breakup. Close friendships keep you on an even keel. They're like a much more fun 401(k)!

She Likes Your Photos on Instagram


Corbis Images

We know, people spend more time looking at their phones than making actual human contact these days. But a recent survey from Pew Research Center found that women who use Twitter several times a day, send or receive 25 emails per day (who doesn't?), and share two digital pics on her phone each day, score 21 percent lower on their stress measure than women who don't use those technologies. Yes, Twitter is actually good for your soul! (Learn more about Why Social Media Actually Lowers Stress for Women.)

She Helps Your Bond with Your S.O.


Corbis Images

Double dates can actually help your own relationship. In a recent study in the journal Personal Relationships, couples reported a boost in "passionate love" after partaking in activities with other pairs. So go ahead and let their PDA influence your own.

She Lowers Your Blood Pressure


Corbis Images

Consider it another byproduct of your friends chilling you out. A 2010 study found that the loneliest participants had a 14 point increase in blood pressure compared to the most social ones. Their friendships were a greater predictor of blood pressure than their weight, smoking habits, or alcohol consumption.