We often write about the importance of having a supportive posse of friends and colleagues and a sense of purpose and play, not just for emotional well-being but also for your physical health.

A workout buddy can boost your physical activity. Friends can inspire you to improve your nutrition and help you negotiate doctor appointments. Committing to helping others through a job or volunteering enriches life, making you more care-full about yourself.

But have we mentioned that pets also help you gain the health benefits that come from having a posse, purpose, and play — especially for older folks living alone?

A study in JAMA Network Open looked at the impact of having a pet on almost 8,000 people ages 50 and older who live by themselves. It showed that not only does having a cat or dog stimulate a daily dose of exercise, lead to interaction with other pet owners, and provide heart-warming love, companionship, and good conversations, it also helps protect your brain's verbal fluency and memory.

And when older people live alone, their risk of dementia increases significantly.

This is good news for the 15 million older American adults who don't have a spouse or a roommate. It's also good news for the 6.5 million animals that end up in shelters each year.

If you live alone and don't have a cat or dog (goldfish and hamsters don't seem to be as beneficial), consider adopting one and joining a local dog group or cat club (they're all over).