Why loneliness can be deadly

. Loneliness can send a person down a path
toward bad health, and even more intense
loneliness, studies have shown. But while some
have assumed the culprit was a dearth of
others to remind a person to take care of
himself or herself, new research suggests there's a direct biological link between being
lonely and ill health. Loneliness can set into a motion a barrage of
negative impacts inside the human body — but
with additional social contact, some of the ill
effects can be stopped. John Cacioppo, a University of Chicago social
psychologist who studies the biological effects of loneliness, presented some of his latest research at the Society for Personality and
Social Psychology meeting in San Diego in
January. He has found, for instance, loneliness is tied to
hardening of the arteries (which leads to high
blood pressure), inflammation in the body, and
even problems with learning and memory. Even fruit flies that are isolated have worse
health and die sooner than those that interact
with others, showing that social engagement
may be hard-wired, Cacioppo said. In one study, Cacioppo and Steve Cole of
UCLA examined how the immune system
changed over time in people who were socially
isolated. They observed a change in the kinds
of genes that lonely people's immune systems
were expressing. Genes overexpressed in the loneliest individuals included many involved in
immune system activation and inflammation. In
addition, several key gene sets were
underexpressed, including those involved in
antiviral responses and antibody production.
The result is that a lonely person's body has let its defenses down to viral and other invaders.
[7 Personality Traits That Are Bad For You] "What we see is a consistent pattern where it
looks like human immune cells are
programmed with a defensive strategy that
gets activated in lonely people," Cole told
LiveScience. Here's why: The immune system has to make
a decision between fighting viral threats and
protecting against bacterial invasions because
it has a fixed fighting capability. In lonely
people who see the world as a threatening
place, their immune systems choose to focus on bacteria rather than viral threats. Without
the antiviral protection and the body's
antibodies produced against various ills, the
result means a person has less ability to fight
cancers and other illnesses. Those who are
socially isolated suffer from higher all-cause mortality, and higher rates of cancer, infection and heart disease. In addition, loneliness raises levels of the
circulating stress hormone cortisol and blood
pressure, with one study showing that social isolation can push blood pressure up into the danger zone for heart attacks and strokes. It
undermines regulation of the circulatory system
so that the heart muscle works harder and the
blood vessels are subject to damage by blood
flow turbulence. Loneliness can destroy the quality of sleep, so that a person's sleep is less restorative, both physically and psychologically.
Socially isolated people wake up more at night
and spend less time in bed actually sleeping,
according to Cole and Cacioppo's research. The cycle created by loneliness can be a
downward spiral. Studies by Cacioppo and
others before him have found that lonely
people tend to rate their own social interactions
more negatively and form worse impressions of
people they meet. "Much like the threat of physical pain,
loneliness protects your social body. It lets you
know when social connections start to fray, and
causes the brain to go on alert for social threats," Cacioppo told LiveScience. "Being
lonely can produce hyper-reactivity to negative
behaviors in other people, so lonely people see
those maltreatments as heavier. That makes it
possible to fall more deeply into loneliness." The reasons trace back to humanity's
evolutionary history, when people needed each
other to stay alive. Loneliness doesn't just
make people feel unhappy, it actually makes
them feel unsafe — mentally and physically.
This powerful evolutionary force bound prehistoric people to those they relied on for
food, shelter and protection, to help them raise
their young and carry on their genetic legacy.
Cacioppo surmises that the distress people feel
when they drift toward the edges of a group
serves as a warning — like physical pain — that they need to reengage or face danger. Everyone feels left out for some period of time,
be it moving to a new city or starting college.
Typically the feelings subside by themselves
within six months. But when it comes to treating
chronically isolated people, some interventions
work better than others. In a large meta- analysis done last year, Cacioppo and colleagues found that two of the best ways to
treat loneliness are to train people for the
social skills they need to view the world in a
more positive light, and to bring people
together to share good times.