Country music legend Hank Williams once crooned, “I’m so lonesome I could cry,” but he could easily have changed the last word to reflect another hard truth: “I’m so lonesome I could die.” Unfortunately, that’s not an exaggeration. Studies continue to reveal links between loneliness and a variety of physical, emotional and mental health problems. However, unlike diabetes, cancer and plaque-filled arteries, it’s not easy to detect.
“Loneliness is tricky because someone has to tell you,” says Kerstin Gerst Emerson, a clinical assistant professor in the Institute of Gerontology at the University of Georgia in Athens. “You can’t give the patient a blood test or an MRI.” Instead, diagnosis depends on asking questions. Living alone isn’t always the problem, although it can be. More important, say experts, is a subjective feeling of social separation. “We’re all lonely from time to time, but the problems come when someone is chronically lonely, day in and day out,” says Steve Cole, a professor of medicine and genomics researcher at the University of California in Los Angeles.
When loneliness becomes a lifestyle, it can have a profound effect on health and can lead to increased levels of stress hormones as well as a heightened risk for heart attack and stroke, dementia, and premature mortality. According to the American Psychological Association, more than 42 million Americans identify as being lonely. The most recent U.S. Census Bureau data indicate that number will only increase: More than a quarter of the population lives alone and nearly half of the population is unmarried. Given this outlook, some health care professionals see not only an incipient public health hazard, but an epidemic.
In fact, much of the current research piles on proof that loneliness can be hazardous to your health. Add it to the list of things to avoid to survive cardiovascular disease. Loneliness can be more dangerous to your health than obesity. In the March 27 issue of the medical journal Heart, researchers in Finland published the results of a seven-year study in the U.K. of nearly 480,000 adults between the ages of 40 and 69. Those with preexisting cardiovascular problems who identified as being lonely and isolated faced serious odds. For those with a history of heart attack, the risk of death increased by 25 percent, and for those who had a history of stroke, the risk went up by 32 percent.
A more recent study, from the May 23 issue of the Journal of the American Heart Association, of patients with heart failure in Minnesota found that in the group of 1,681 men and women, with an average age of 73, the 6 percent who reported a high level of perceived social isolation had a greater risk of hospitalization, ER visits and early death than those who did not.
In an effort to understand the biology behind the detrimental relationship between loneliness and serious health issues, UCLA’s Steve Cole and the late John Cacioppo did a pilot study using blood samples from older adults in the Chicago area. What came out clearly even in that small study was that the genes involved in inflammation were working overtime.
Mature white blood cells produced in bone marrow are a first line of defense against infection, but immature cells don’t get the message. Instead, they cause inflammation and reduce antiviral protection. These immature cells proliferate in the blood of lonely people. “Inflammation is a great thing to have when you’re injured, but if inflammation is running all the time, it functions as a kind of fertilizer for the development of atherosclerosis, heart attacks, neurodegenerative diseases like Alzheimer’s and metastatic cancers,” says Cole.
In addition, in a kind of double whammy to people who are socially isolated, the study found that they have reduced activity of the antiviral genes that protect us from various infectious diseases. Lonely people may not catch colds and other infections more easily, but when they do they have a more severe case because antiviral immunity seems to be weaker. Chronic loneliness “creates a sense of threat, and that insecurity is activating pathways in the body that change the gene’s activity,” Cole says.
It’s not just our bodies that react negatively to loneliness and social isolation. Our brains are vulnerable, too. Naomi Eisenberger, associate professor of social psychology and director of the Social and Affective Neuroscience Laboratory at UCLA, found that scans of those suddenly being excluded from a game of virtual “catch” showed increased activity in the same regions of the brain that are associated with physical pain. “Being disconnected from the rest of the world in a somewhat hostile or insecure way is the core of chronic loneliness,” says Cole.
Nancy Donovan, a psychiatrist and researcher at the Center for Alzheimer Research and Treatment at Brigham and Women’s Hospital in Boston, used data from the Harvard Aging Brain Study to compare self-reported loneliness with the amount of amyloid levels in the brain. (Amyloid is a protein that plays a key role in memory.) The results, published in JAMA Psychiatry in November 2016, were that 32 percent of the participants who identified as lonely tested positive for high amyloid levels — a warning sign for Alzheimer’s disease.
An unintended consequence of this quality-of-life issue is its impact on the health care system. Emerson was curious as to why so many doctors were complaining of unnecessary office visits by people who were not really sick. She and a colleague reviewed responses of 3,530 American adults 60 and older who took part in the University of Michigan Health and Retirement Study in 2008 and 2012. Their research, published in the American Journal of Public Health in 2015, confirmed the anecdotal data. They found that people who identified as lonely in both surveys — therefore, considered chronically lonely — had an increased number of physician visits. This is an inefficient use of the doctor’s time and of health care dollars, Emerson points out. In fact, the AARP Public Policy Institute estimates that social isolation is associated with $6.7 billion in additional Medicare spending.
A few days of loneliness aren’t toxic, says Steve Cole. But when days add up to weeks, months and decades, “the subtle biological impact of the way we live our lives starts to really add up in terms of disease development,” he says.