The key to avoiding illness is our lifestyle! And here are a few easy changes that can boost your immune function and help prevent everything from your next cold or flu – or possibly, even a heart attack:

First: Hang out with the people you love! Studies show that people with at least 6 close connections – friends, family and even coworkers - are 4 times better at fighting off the cold virus than those with fewer friends. Because we’re less stressed when we have a strong social network, especially when we know they’ve got our back. That’s why married men are healthier than single men – because their wives are looking out for their health. And your friends can serve the same function – encouraging you to get check ups, or to quit smoking.

Another way to boost your immune system: Stop being a night owl! People who sleep 8 hours a night have significantly more germ-killing cells than those who sleep less. According to the University of Chicago, good sleepers also produce twice the flu-fighting antibodies than the sleep-deprived. If you’re tired when you wake up in the morning – you’re not getting enough sleep.

Another way to boost your immunity: Be an optimist! In a recent study, pessimists who tried to put a positive spin on things were less stressed, and had a better immune response than Debbie Downers. Why? Optimists usually take better care of themselves. They’ve also got less stress-related damage to their immune system like, germ-killing cells that suddenly stop working. An easy trick: Keep a gratitude diary.  Studies show that people who keep track of what they’re grateful for are happier and more optimistic.

Finally: Get more exercise. Experts say that 1 in 4 North Americans don’t get any exercise which is a fast track to getting sick. But people who walk briskly on most days take half the sick days as those who don’t take walks. Because just 30 minutes of aerobic exercise helps sweep white blood cells back into circulation, making your immune system run more smoothly.