Study: what is the impact of loneliness on life expectancy?

Lonely older adults are more likely to live shorter lives than their peers and spend less of their remaining life in good health or being active, according to a new study in Singapore and Japan.

The study categorically quantifies for the first time the affects of loneliness in old age on life and health expectancy.

“We found that lonely older adults can expect to live a shorter life than their peers who don’t perceive themselves as lonely,” says lead author Rahul Malhotra, assistant professor and head of research at Duke-NUS’ Centre for Aging Research and Education (CARE). “Furthermore, they pay a penalty for their shorter life by forfeiting potential years of good health.”

“Besides being the year associated with the coronavirus disease, 2019 was also when the number of adults aged over 30 made up half the total global population for the first time in recorded history, marking the start of an increasingly aging world,” says senior author Angelique Chan, associate professor and executive director of CARE. “In consequence, loneliness among seniors has become an issue of social and public health concern.”

“This study is timely because stay-at-home and physical distancing measures instituted since the start of the COVID-19 pandemic have only intensified concern for the mental and physical well-being of older persons,” says Yasuhiko Saito from the College of Economics at Nihon University and a senior coauthor of the study.

The study findings show that people aged 60, who perceive themselves to be sometimes lonely or mostly lonely, can expect to live three to five years less, on average, compared to peers who perceive themselves as never lonely. Similarly, at ages 70 and 80, lonely older people can, on average, expect to live three to four and two to three years less, respectively, compared to non-lonely peers.

Using the same dataset, the researchers found that the perception of loneliness has a similar effect on two types of health expectancy—remaining years of life lived in a self-rated state of good health as well as remaining years of life lived without being limited when going about “activities of daily living.” Such activities include routines like bathing and dressing, rising from or settling into a bed or chair, and preparing meals.

At age 60, sometimes lonely or mostly lonely seniors can expect to spend three to five fewer years of their remaining life, on average, without limitations in daily living activities, compared to never-lonely peers. At age 70, their active life expectancy goes down to two to four fewer years, on average. At age 80, it is at one to three fewer years, on average.

Singapore is a particularly relevant setting for studying how loneliness impacts older adults because the country has a rapidly aging population, and a “collectivistic” culture, in which relationships and the interconnectedness between people are central—in contrast to an “individualistic” culture, where each individual’s needs and desires are considered to be more important.

Previous studies found levels of loneliness to be higher in collectivistic societies, suggesting loneliness may have a more detrimental impact in Singaporean society.

In 2016 and 2017, CARE researchers conducted a study—known as the Transitions in Health, Employment, Social Engagement, and Intergenerational Transfers in Singapore (THE SIGNS) study—to look into factors influencing health, well-being, and activity and productivity levels in older Singaporeans.

Nationally representative data, collected from more than 2,000 older Singapore citizens and permanent residents, showed that a third (34%) perceived themselves to be lonely. This proportion increased with age, from 32% among those aged 60-69 years, to 40% among those aged 80 and above.

More males (37%) were lonely, relative to females (31%). Across education levels, the proportion of lonely older Singaporeans was lowest (33%) among those with no formal education, and highest (38%) among those with higher-than-tertiary education. This proportion was nearly 10% higher among seniors who lived alone (43%) compared to those who did not live alone (33%).

“Building on THE SIGNS study, our recent findings highlight the population health impact of loneliness, and the importance of identifying and managing it among older adults,” says Malhotra. “This is part of a series of studies to assess the impact of important health and social constructs, like loneliness, sensory impairments, obesity, gender, and education, on life and health expectancy among older adults.”

“With older persons at potentially greater risk of loneliness as a result of pandemic control measures, there has been increasing policy interest in loneliness around the world,” Chan says. “In 2018, the UK launched a national strategy for tackling loneliness and, in 2021, Japan appointed a “Minister of Loneliness.” We hope this study helps galvanize more policies to tackle loneliness among older persons.”

Scientifically, loneliness is a subjective (or self-perceived) phenomenon in which an individual feels a discrepancy between their desired and actual social relationships.

It is important to distinguish loneliness from social isolation or living alone, experts say. While loneliness represents someone’s perception or feeling of being socially isolated, social isolation is an objective or actual state of having few social relationships or infrequent social contact with others.

In the same way, living alone in a single-person household without any family or friends does not equate to being lonely. Conversely, having a wide social network, frequently interacting with friends or family, or even living with family or friends need not mean that an individual does not feel lonely.

Previous studies have reported that loneliness increases the risk of poor health outcomes, including death. However, the extent to which loneliness affects life expectancy among older adults has never been explored, leading the research team to seek the answers themselves.

Using longitudinal data from a previous survey, researchers conducted of more than 3,000 older Singapore citizens and permanent residents, the research team set out to estimate the number of years that older people, aged 60, 70 and 80 years, can expect to live if they are “not lonely,” or only “sometimes” or “mostly” lonely.

The survey participants were administered a commonly-used scale for assessing loneliness, comprising three questions:

How often do you feel that you lack companionship?How often do you feel left out?How often do you feel isolated from others?

Based on their responses, researchers categorized them as “never lonely,” “sometimes lonely,” or “mostly lonely.” The researchers accounted for other factors that could affect life or health expectancy, such as gender, education, chronic illnesses, or depressive symptoms.

The paper appears in the Journal of the American Geriatrics Society.

Source: Duke-NUS