February 22, 2002

Study links loneliness to health effects

Chronic loneliness is a major risk factor for emotional and physical disorders that lead to early death, according to a study recently published by John Cacioppo, director of the social psychology program and co-director of the Institute of Mind and Biology at the University.

"Chronic loneliness is the feeling of isolation and disconnectedness from others," Cacioppo said. "We determined from the sample that [those afflicted by loneliness] weren't actually isolated, but they felt a certain emotional emptiness."

Among 2,600 students surveyed at Ohio State University, Cacioppo found no evidence that physical appearance and economic status had anything to do with feelings of loneliness. "We took photographs, we had blind judges score how attractive they were, we measured their height and weight, calculated their body mass — lonely and non-lonely didn't differ in those cases," he said.

Loneliness was found to be linked to behavioral patterns, such as hostility, pessimism, and insecurity in group situations, that are said to be the cause of cardiovascular disease later in life. Cacioppo said that lonely students were more stressed out by the same events that non-lonely students were not worried about.

"If a socially connected person has an exam, they'll actively prepare for it. If they see a homeless person, it's a chance to make a new friend. They're just happy, optimistic people," he said.

According to a follow-up study by Cacioppo published in the recent issue of Psychosomatic Medicine, loneliness has been found to exist completely independent of health behaviors such as smoking or exercising. Both lonely and non-lonely persons have the same statistical distribution of good and bad exercise habits.

"A lonely person who's smoking on average will die younger than a lonely person who's not smoking," Cacioppo said, "but there's just as many people who are lonely that smoke as those who are not lonely and smoke."

Over time, however, lonely people's bad habits will accumulate to cause health disorders. According to Cacioppo, lonely people are more likely to smoke, drink, and eat junk food. They don't regularly take care of themselves.

"We know that those behaviors are big causes of morbidity and mortality," he said.

Those who are affected by loneliness are also more likely to have irregularity in their sleep patterns. They will tend to wake many times during the night or experience prolonged insomnia. Throughout a variety of tests in different locations, lonely people consistently complained of poorer sleep.

Lonely individuals regularly experience abnormal levels of stress. According to Cacioppo, stress leads to more wear and tear on the biological systems that make the body function. Because of a lonely person's increased tendency for stress, the body will be more physically worn down.

Lonely individuals experience stress patterns similar to their socially connected counterparts; lonely people, however, generally lack the ability to repair tissue, otherwise known as anabolic processes. This ability is found in many individuals who are physically active. Cacioppo gave the example of the professional athlete. An athlete is able to convert bodily stress into tissue growth through anabolic processes.

"There's a growth as well as a stress side of this equation," he said.

Cacioppo cited an example of an oral surgeon who treated the same standardized oral wound in two different individuals. In these two cases, it took longer for the lonely person to heal the wound than the socially connected person.

Cacioppo also tested a number of adults over 65 years old and found that most who were lonely had elevated blood pressure. Because lonely people on average have small arterial walls, they are subject to greater pressure. When the neurons in the lower brain are continually asked to exert greater pressure, the artery walls shrink over time.

Cacioppo used the example of a garden hose. "If you have a large hose and a small hose, over years of watering your lawn, which hose will degrade the fastest? The small hose," he said.

The Institute of Mind and Biology recently received $7.5 million from the National Institute of Aging to do an extended follow-up study of the physical effects of loneliness on older adults. The participants will be seniors living in Chicago ranging in age from 50 to 64 years old. The study will continue with the same subjects once a year for five years and will test such phenomena as sleep deprivation and prolonged isolation.

Cacioppo is currently trying to expand his research to include shift workers, studying the effect of sleep deprivation on their social relationships. He is looking to enlist the research abilities of Dr. Eve Van Cauter, a professor of endocrinology at the University who has done several sleep studies at the medical school.