This week the Today show is running a series on “The New Middle Age” with journalist Joan Lunden doing the segments. One of the segments was on the importance of friendship in middle age. To demonstrate the value of friendship, Joan and her friend of 15 years, Louise, took part in a neuroscience experiment.

Louise was put in an MRI machine where she would be given cues that would indicate whether or not she might get an electric shock to her ankle. The test was designed to create anxiety. The experiment was conducted three ways: Louise alone in the scanner; with a stranger holding her hand; and with her friend Joan holding her hand. The purpose of the experiment was to evaluate how people regulate anxiety in these three different circumstances.

Not surprisingly, the brain scans showed blood activity to the brain when Louise was alone or when a stranger held her hand, but when Joan was with Louise, those areas of her brain were quiet. Said Louise of the experience, when Joan walked in, “I felt she had my back.”

Many of us are familiar with the experience of relaxing when you hear your friend’s voice, feel her touch or look into her eyes. Close friends soothe. They comfort. They let you know you are not alone.

In fact, research shows that people with a large network of friends live longer and are healthier. But U.S. census bureau data from 2013 shows a disturbing trend: people ages 45 to 64 were 29% more likely to live alone than they were 10 years ago. So more than ever before it is important that we make time for friends and cherish the ones we have.