Loneliness can be deadly

According to a study made by the University of Chicago, being cut off from other people weakens our ability to fight off viruses as well as pushes the blood pressure into the danger zone of heart attacks and strokes.

Loneliness can cause heart attacks and strokes

Researchers from the University of California and University of Chicago found that lonely people’s immune responses is less effective compared to non-lonely people. In comparison, lonely people also have increased body inflammation. They also feel threatened in a social manner, which affects their health tremendously.

What the research team found is that perceived social isolation—the “feeling of loneliness”—was strongly linked to two critical physiological responses in a group of 141 older adults: compromised immune systems and increased cellular inflammation. Both outcomes are thought to hinge on how loneliness affects the expression of genes through a phenomenon the researchers call “conserved transcriptional response to adversity,” or CTRA.

The longer someone experiences loneliness, the greater the influence of CTRA on the expression of genes related to white blood cells (aka, leukocytes, the cells involved in protecting us against infections) and inflammation. CTRA decreases the genetic expression of white blood cells while simultaneously increasing the genetic expression of inflammation. Inflammation refers to damage at the cellular level rather than the swelling that accompanies an injury; the injury, in this case, is happening within the body’s cells.

In a study of 141 older adults, researchers looked at the relationship between loneliness and patterns of gene expression in white blood cells, which are involved in protecting the body against viruses and bacteria. They’ve found the same effect as in their previous study, that loneliness causes an increased gene expression for inflammation while the gene expression for the immunes system’s fight against antiviral infections is decreased.

He added: “The “danger signals” activated in the brain by loneliness ultimately affect the production of white blood cells”. They believe that the resulting increase in the number of monocytes may both propagate loneliness and contribute to its associated health risks.

Loneliness can lower the white blood cell count people’s body, lowering their immune systems

Their previous study found a link between loneliness and a phenomenon called “conserved transcriptional response to adversity” (CTRA).
Researchers at the University of Chicago have found that those who are lonely are more likely to have a lower immune system.Other studies showed that the increased production of immature monocytes was amplifying the high inflammation/low antiviral effect in the pool of white blood cells. The study also revealed that loneliness predicted that these cellular changes would occur a year or more later. This indicates that leukocyte gene expression and loneliness work together to exacerbate each other over time.

Next, the team investigated the cellular processes linking social experience to CTRA gene expression in rhesus macaque monkeys at the California National Primate Research Centre, which had been behaviourally classified as high in perceived social isolation. Both lonely humans and “lonely like” monkeys showed higher levels of monocytes in their blood.

The combination of the two effects is potentially lethal. A lessened ability to fight infections along with a slow erosion of cellular health leaves the body open to a host of external and internal problems, some of which worsen over time with few distinct symptoms.

“Perceived social isolation is a risk factor for chronic illness and all-cause mortality but the molecular mechanisms remain ill understood. In humans, loneliness involves an implicit hyper-vigilance for social threat,” said John Capitanio from the University of California.

The researchers analyzed the effect of loneliness in humans and a highly social type of primate species, the rhesus macaque. A past research involving the two species found a link between loneliness and a biological phenomenon called conserved transcriptional response to adversity (CTRA). The phenomenon’s identifying factors are the increased activity in genes responsible for inflammation and decreased activity in genes responsible for antiviral reactions.

The cumulative findings showed that loneliness affects the “fight or flight” response, which then increases production of immature monocytes in the blood. High levels of monocytes increases the activity of inflammatory genes. Increased monocytes’ presence in the blood lowers the activity of genes responsible for fighting off viruses and bacteria. The blood of lonely macaques and humans showed high levels of monocytes. Monkeys who were continually thrusted into slightly stressful situations such as new and unfamiliar cage-mates showed increased levels of monocytes.

The study also found that CTRA and loneliness have a reciprocal relationship: loneliness predicted CTRA gene expression more than a year later, and CTRA gene expression predicted loneliness more than a year later. In other words, loneliness and CTRA propel each other over time, one pushing the other as physical health is eventually undermined. The reasons why this reciprocal relationship exists aren’t entirely clear.

The results, the researchers emphasized, are “specific to perceived social isolation” and can’t be explained by stress or depression.

The researchers also studied the effects of social isolation in a group of rhesus monkeys and found the same pattern of increased CTRA activity, along with a heightened “fight or flight” chemical response. The combination of effects led to impaired immune systems that allowed viruses, like the simian version of HIV, to grow faster in the monkeys’ blood and brain tissue.

Loneliness activates “danger signals” in the brain which disrupts healthy production of white blood cells. Heightened monocyte production may intensify loneliness and influence health risks.

The next disturbing effect they found is the increased levels of norepinephrine, the “fight or flight” neurotransmitter, in lonely macaques. Past research explained that norepinephrine triggers bone marrow’s blood stem cells to create more immature monocytes. The increased production of immature monocytes explained the heightened CTRA activity in the white blood cell pool.

They also discovered that loneliness can predict CTRA activity one year or further into the future and vice versa. The findings were definite to loneliness and are not connected to other forms of dangers like stress and depression.

The research team included noted University of Chicago loneliness researcher John Cacioppo, who also published research earlier this year on the brain differences between lonely and non-lonely people. In that study, Cacioppo found that the brains of lonely people display a “hyper-vigilance” to perceived social threats. Certain socially negative words (like “alone,” “solitary,” and “sad”) triggered responses in the lonely participants’ brains significantly more pronounced than responses from non-lonely participants’ brains, suggesting a rapid shift into self-preservation mode in the lonely brain.

The self-preservation trigger may be linked to the physiological responses found in the latest research, though future studies will have to probe the connection further. For now, we have another big clue as to how loneliness affects overall health.

The research team is pushing forward to discover how loneliness can lead to poor health conditions and how it can be intercepted in senior adults.