Loneliness: A Boon for Neither the Heart
nor the Mind

Thomas Kron, MD

March 11, 2022

Loneliness is associated with cerebral and cardiovascular diseases, according to recent studies. A study published last month in the journal Neurology, for example, suggests that loneliness is linked to an increased risk for dementia.

Increased Risk for Dementia

For this study, the authors retrospectively analyzed data that were collected prospectively from the population-based cohorts in the Framingham study, which was conducted over a 70-year span (1948 through 2018). Loneliness was defined as the feeling of loneliness on 3 or more days in the past week.

Out of the 2308 participants (average age, 73 years; 56% women) who had no dementia at the start of the study, 14% (329) developed dementia within 10 years; 6% (144) fulfilled the criterion for loneliness. The calculations indicate a 10-year dementia risk that is more than 50% higher for lonely adults, compared with not-lonely adults (age-, gender-, and education-adjusted hazard ratio, 1.54; 95% CI, 1.06 - 2.24).

For lonely participants younger than 80 years without the APOE-ε4 allele (a risk factor for Alzheimer's disease), the calculations indicated an even higher risk (adjusted hazard ratio, 3.03; 95% CI, 1.63 - 5.62). According to further analyses, loneliness is linked to poorer executive function, a lower overall cerebral volume, and greater damage to the white matter.

Severe Cardiovascular Disease

A study published last month in JAMA Network Open suggested that social isolation and loneliness in elderly women in the United States were associated with a 27% higher risk for severe cardiovascular disease. As reported by Medscape, approximately 60,000 women aged 65-99 years participated in the study. "The findings suggest that these prevalent psychosocial processes merit increased attention for prevention of CVD in older women, particularly in the era of COVID-19," write researcher Natalie Golaszewski, PhD, behavioral research scientist at the University of California, San Diego, and colleagues.

For their study, Golaszewski and colleagues analyzed data from the Women's Health Initiative Extension Study II, which collected data between 2011 and 2019. The participants, 57,825 women with an average age of 79 years, had had neither a myocardial infarction nor a stroke at the start of the study, and they also did not suffer from coronary heart disease.

Over 186,762 person-years, a total of 1599 severe cardiovascular events occurred. Taking into account the factors mentioned, especially the women's health behavior and condition, the researchers determined that social isolation increased the risk for severe cardiovascular events by 8%, and loneliness increased it by 5%. When the participants' health behavior and condition were not included in the analysis, the corresponding values were 18% and 14%. Women who were strongly isolated socially and who also felt very lonely had a 13%–27% higher risk of developing severe cardiovascular events, when compared with women without these two factors.

Loneliness as a Lifestyle  

Loneliness has been a subject of scientific study for several years. Even the rich and beautiful in Hollywood have taken it up. The lone wolves howled at us through every medium, wrote journalist Michael Allmaier in the weekly newspaper Die Zeit a few years ago. Dozens of Hollywood stars reportedly adopted the role of mysterious stranger or even of the bright-eyed and bushy-tailed single person. Lifestyle authors celebrated the new "life feeling" and the "way to inner freedom," the "art of enduring."

And lots of people bought it. Why else, continues Allmaier, "do droves of truth seekers make the Camino de Santiago pilgrimage, or lock themselves away at silent retreats? Loneliness is the new yoga." However, those who are truly lonely are rarely happy. In reality, they are "poor pigs, who neither see nor hear anyone." 

"I have never said, 'I want to be alone.' I have said, 'I want to be left alone.' There is huge difference," said the actress Greta Garbo, hitting the nail on the head. People can live alone, be socially isolated, and nevertheless feel neither lonely nor unhappy. In contrast, other people can feel lonely in a large city and an apartment block and suffer as a result. To put it somewhat abstractly, the term "loneliness" can be defined as the uncomfortable or severely mentally draining feeling that arises from a large discrepancy between the desired extent of social contact and the reality.

According to Nancy J. Donovan, MD, neurologist and psychiatrist at Brigham and Women's Hospital in Boston, there is a correlation between loneliness and social interactions, but not for everyone.

But "just because someone is alone, it does not mean that they are lonely. Someone is only lonely if solitude is painful for them, if they feel isolated, or like they don't belong anywhere," clarifies Manfred Beutel, MD, director of the Clinic for Psychosomatic Medicine at the University Hospital of Mainz, Germany, in an article in Der Spiegel.

But some people suffer from loneliness. A Spiegel article reported on a study by Maike Luhmann, PhD, professor of psychology at the Ruhr University Bochum, Germany, that found that 1 in 5 people over age 85 years in Germany feels lonely. For those aged 45-65, the rate is 1 in 7 people. "There is no age category in which people do not feel lonely," said Luhmann. Elderly, ill people who are barely able to leave their house are particularly affected. "It's a vicious cycle, since social isolation can foster illnesses such as depression or cardiovascular diseases. More and more people are expected to be affected. There has even been talk of a deadly 'epidemic.' "

The loneliness researcher Julianne Holt-Lunstad, PhD, professor of psychology and neuroscience at Brigham Young University in Provo, Utah, believes that loneliness and social isolation are an even bigger health problem than obesity. Two large meta-analyses have shown that social isolation and loneliness are associated with an elevated risk for premature death, as she reported at a conference of the American Psychological Association in Washington, and at the Aspen Ideas Festival in Colorado.

Medical and Political Perspectives  

There is now a plethora of scientific evidence that people suffering from loneliness are particularly at risk of becoming ill. Crucially, those affected are more commonly depressed and have an unhealthy lifestyle, as revealed in a study by Beutel from 2017. And according to a meta-analysis published in 2016, loneliness and social isolation are associated with an increased risk for coronary heart disease and stroke. Furthermore, evidence has for many years suggested a correlation between loneliness and early mental deterioration. Loneliness may be an early symptom of Alzheimer's disease, as indicated by a study by Donovan et al that found a correlation between loneliness and cerebral amyloid burden.

The topic has also kindled political interest in recent years. Among other officials, Karl Lauterbach, PhD, MPH, federal minister of health in Germany, called for "more to be done against it," because of the potentially negative consequences of loneliness. Whether he will announce specific measures to address this problem remains to be seen.

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