We are not sure why relationships play a role in health and life expectancy. It could be that people in positive relationships are less likely to take on risky behaviors and are more likely to take care of themselves. It could be that having people around you reduces the impact of stress on your health. We can make up lots of theories about why relationships have a positive impact, but the bottom line is that people who are engaged in "meaningful" relationships have better health (and therefore better life expectancies).
One way of improving your relationships with people is to get in the habit of telling good stories. Stories are how we communicate with one another, and telling a good story strengthens communications. I can't count the number of times I've been on the phone with someone and was just talking about the weather or giving a dry update on my family. Instead, I should be telling a story about a funny thing my kids did or something crazy that happened at work. Stories keep relationships alive.
So make more time for friends and family. Go do things together (create stories together), and make a real effort to improve your communication with them (whether by e-mail, phone or in person) by having a good story always ready for the telling.
Read More: Relationships and Life Expectancy