A recently published letter by leading public health experts in the medical journal Lancet calls for an aggressive global approach to challenge loneliness. Chronic loneliness can happen at any stage of life, but a driving factor behind rising concern is the potential for the litany of health problems associated with loneliness and social isolation to worsen with the aging of the population.

The public health concerns about loneliness and social isolation reflect scholarly research that strongly suggests being alone can contribute to shorter lives, cognitive decline, physical deterioration and depression. For example, a study by Julianne Holt-Lunstad, professor of psychology and neuroscience at Brigham Young University, found the mortality impact of loneliness is equivalent to smoking 15 cigarettes a day. (Loneliness refers to little connection to family and friends, while social isolation is more about living alone.)

Loneliness and social isolation reflect major social and economic forces, such as the way our homes and communities are designed and changes in family structure. Twenty years ago, the sociologist Robert Putnam published "Bowling Alone," documenting the decline of social institutions and activities that used to bring people together. The complex web of connections, relationships and civic culture that traditionally bound communities together us are fraying.

The health concerns about loneliness don't seem like a classic personal finance topic. Yet thinking about how to avoid loneliness is critical to savvy retirement planning. The topic matters as much as financial calculations. Discussions with family, friends and others in your network about connections and engagement should be a priority as retirement looms.

For example, where you will live? Is it easy to meet those close to you from where you now live? The community of connections that come from work (as well as income) is why many people choose part-time work during retirement years. What kind of work will you do if a job is part of your portfolio of activities in retirement?

Many people want to volunteer more later in life. Thoughtfully planning your volunteering will hike the odds of a rewarding experience. Talk to those close to you — family, friends, network — about staying in touch.

We're social creatures. Connections matter. Put high on your retirement plan maintaining and nurturing connections. The return on investment is a higher quality of everyday life.

Chris Farrell is senior economics contributor, "Marketplace"; commentator, Minnesota Public Radio.