February 9th, 2011
04:37 PM ET
In the run-up to Valentine's Day, some of you may be excited for romance, and others may be bitter about solitude. It's no fun feeling lonely, and now there's even more research to show that loneliness may be bad for your health.
Loneliness isn't about the number of people around you; it's a state of mind about feeling like you can't count on anyone in the uncertain, threatening world in which you live.
UCLA researcher Steven Cole and colleagues have demonstrated that this mindset may be harmful to your health. In a study of 93 adults, published in the Proceedings of the National Academy of Sciences, they found that people who say they're chronically lonely have an overexpression of genes connected to cells that produce an inflammatory response to tissue damage.
While that's good in the short run, it's common knowledge that long-term inflammation leads to cardiovascular disease and cancer.
There's a good evolutionary explanation for all of this: Back when most humans didn't live long enough to worry about those ailments, people who were alone needed their bodies to have extra defenses against injury and bacterial infections that they could pick up from a wound from a predator. On the other hand, those in the company of trusted peers didn't have to worry as much about such injuries, but they were more likely to pick up a virus from others, so they would need to have stronger antiviral defenses.
This is just a correlation between gene expression and loneliness of course; it's not certain that one causes the other, but this is just one of many studies showing a connection between poor health outcomes and loneliness. Anti-inflammatory drugs may be appropriate for some people who can't get out of the lonely mindset, Cole said.
"The more we can learn about the biological mechanisms of these effects, the more we may be able to protect people from them pharmacologically," Cole said. On the other hand, "if you want to change your life philosophy and think of world as a more supportive environment I think thatâ€™s a great thing."
Fitness and companionship
You may have found that a romantic partner to exercise with can really help your motivation. The New York Times delves into this topic of relationships and fitness, surveying research suggesting that lonely people may not reap the same benefits of exercise as those who are coupled.
Now, a lot of this is based on rodent studies. It seems that rats' brains generate new neurons and neural connections only when exercising with other rats. It appears that this is true for both male and female rats, but we don't yet know about humans. Alexis Stranahan tells the Times that it may take longer for people to reap brain improvements from exercise if they are lonely, because of the stress hormones associated with loneliness.
For what we do know about humans and exercise, companionship isn't always foolproof. A study published in December found that married women and remarried men often got less fit, and single women who remained single kept fit; men who divorced gained fitness.
Love is healthy
But there are plenty of health benefits to falling in love, and staying in love, as the Washington Post points out. A 2008 study found that blood pressure is lower among married people than unmarried people, and those with the highest blood pressure are unhappily married. And a Carnegie Mellon University study found that people in love tend to get fewer colds.
As usual, it sucks to be lonely and it's great to be in love, but there are all kinds of subtleties about why.
About this blog
Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.