Last month, older adults in Singapore were urged to stay home as much as possible as the nation battles the latest wave of coronavirus infections. Such social isolation was a hallmark of the early pandemic days and continues to be relied upon by countries, like Singapore, that are shifting from a zero to endemic COVID-19 strategy.

These measures—while necessary to mitigate the impact of the pandemic—have increased concern among researchers focusing on ageing-related issues.

“The stay-at-home and social distancing measures instituted since the start of the COVID-19 pandemic have only intensified concern for the mental and physical wellbeing of older persons,” said Angelique Chan, an associate professor at Duke-NUS and director of the Duke-NUS’ Centre for Ageing Research and Education (CARE).

One knock-on effect that Chan and her colleagues at CARE are particularly concerned about is loneliness. While social isolation does not mean that an individual is lonely, it may affect how individuals perceive themselves and exacerbate existing feelings of loneliness or induce such feelings. Even before the pandemic, a study by CARE, conducted from 2016 to 2017, found that one in three older Singaporeans or permanent residents perceived themselves as lonely.

Now the team at CARE in collaboration with Nihon University has—for the first time—categorically quantified the impact of loneliness on life and health expectancy in older adults.

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

The study, which was published in the Journal of the American Geriatrics Society, found that people aged 60, who perceive themselves to be sometimes 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 persons can expect to live three to four and two to three years less, respectively, on average compared with non-lonely peers.

Using the same dataset, the researchers found that the perception of loneliness has a similar impact on two types of health expectancy: remaining years of life lived in a self-rated state of good health as well as their active life expectancy and 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 or mostly lonely seniors can expect to spend an average of three to five fewer years of their remaining lives 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 goes down to one to three fewer years on average.

“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 ageing world,” said Chan. “In consequence, loneliness among seniors has become an issue of social and public health concern.”