Loneliness May Raise Blood Pressure

One of my Harvard colleagues, Robert Putnam, wrote a book called Bowling Alone, about how people are becoming less connected to others. The example he uses to illustrate his point has to do with the most popular sport in America—bowling. Even as Americans bowl in increasing numbers, leagues are rapidly declining. Hence, people are bowling alone. Putnam uses the term “social capital” to describe how wealthy we are in human connections. This concept may play a surprising role in blood pressure.

Certainly risk factors for high blood pressure are well known: excess weight and family history are the most important, and a high salt diet, smoking, and excessive alcohol intake may contribute as well. But there is plenty we don't know about hypertension. Perhaps the biggest mystery is why some people have it despite the absence of risk factors while others with multiple risk factors maintain a normal blood pressure. Could a low level of social capital be a risk factor?

A study published last year suggests that it might.

The study, published in the current issue of Psychology and Aging, was carried out by researchers in Chicago where 229 men and women ages 50 to 68 were surveyed about standard risk factors for hypertension and about their degree of social isolation. Blood pressure was measured and correlated with the subjects' answers about social interactions. The results were remarkable: the highest blood pressures were measured in the people who were most lonely. And loneliness was common: just over half were considered at least moderately lonely and 15% were "highly lonely." The link between social isolation and high blood pressure remained strong even when standard risk factors for hypertension were taken into account.

What does this mean? On the one hand, it's important to note that this type of study cannot prove causation – that is, the finding of an association between high blood pressure and lack of social interaction is not the same as finding that loneliness causes hypertension. There could be other explanations for the link, including the possibility that it's just a coincidence; or, perhaps the study's findings could be explained by "confounding." That is, maybe there's another factor responsible for increased blood pressure that is more common among lonely people. For example, lonely people might exercise less and eat a higher salt diet and that's what raises blood pressure, not the social isolation.

Then again, this study is not the first to link loneliness with negative health effects. Other recent research has linked it with abnormal blood vessel response to stress, blood tests associated with higher risk of cardiovascular disease and an increased risk of death. It's probably premature to accept these studies as proof that social isolation causes cardiovascular disease, but as the evidence mounts, it's harder to explain these findings in any other way.

Lessening your loneliness

Whether or not social isolation actually causes hypertension, loneliness can be a big problem, especially with advancing age: children grow up and move out, retirement removes older people from the social interactions of the workplace and aging friends and family may become ill or die.

Reducing loneliness may not be easy or even desired; some people may prefer the peace and quiet of living alone – perhaps, for them, blood pressure is better being on their own. But, as pointed out in this latest study, it's worth noting the possibility that social isolation is bad for your health.

There are a number of changes you can make to reduce loneliness. For instance:

· Become a volunteer – choose a cause you believe in and look for opportunities to help; you may be improving your health as well

· Get a pet – the social interaction you have with your pet may have far-reaching benefits; for example, walking your dog is a way to increase your physical activity and it's likely your dog will bring you into contact with other dog owners

· Get an exercise partner or joining a gym – having one or more exercise partners may increase the chances you'll stick with an exercise program while also reducing social isolation

· Organize a weekly book club, card game or other activity you enjoy

Similarly, independent of whether or not you are socially active, there are a number of changes you can make to prevent or improve hypertension, such as:

· Maintaining an optimal body weight and exercising regularly

· Improving your diet by moderate salt intake, increasing fiber, fruits and vegetables, and reduce intake of saturated fat – the DASH eating plan is a great starting point

· Moderating your alcohol intake (no more than 2 drinks per day for men or 1 drink per day for women; even less may be optimal if your blood pressure is high)

· Not smoking and avoiding second-hand smoke

· Get your blood pressure checked regularly, even if it's normal – that's especially important if you have a family history of hypertension.

What do you do when you’re feeling lonely? Have you found ways other than those listed to help prevent feeling lonely?

Julie K. Silver, M.D., is an assistant professor in the Department of Physical Medicine and Rehabilitation at Harvard Medical School. She is also the Chief Editor of Books for Harvard Health Publications.

Hypertension
Reducing your blood pressure even a little bit can dramatically improve your health and life expectancy. Harvard Medical School’s report, Hypertension: Controlling the silent killer, lays out a step-by-step lifestyle program you can use to lower your blood pressure. It also covers blood pressure monitoring and medications. With the information available today, there is no need for hypertension to be a killer any longer.