Loneliness in Older Adults Increases the Risk for Physical Frailty

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A new study found older adults who are frail are less likely to engage in social interactions, which can cause them to lose social contact and create loneliness.

A new study found loneliness in older adults increases the risk of physical frailty, which in turn increases the risk of depression, falls, and cognitive decline.1

“Recently, and especially during the COVID-19 pandemic, there is more attention for the potential harmful effects of loneliness and social isolation on the health of older people,” said investigator Emiel Hoogendijk, an epidemiologist at Amsterdam Public Health, in a press release.2 “We wanted to see how far these effects went and saw that all kinds of reduced social functioning, such as loneliness, social isolation and lack of social support, were associated with physical decline in older adults.”

A US Surgeon General claimed last year that loneliness is just as harmful as smoking 15 cigarettes per day. Loneliness increases the risk of depression and other chronic diseases. Limited social contact can directly hurt the immune system and indirectly hurt health as these individuals may adopt an unhealthier lifestyle.

Investigators, led by Peter Hanlon, PhD, a clinical research fellow at the University of Glasgow, along with investigators from Amsterdam UMC, Canada, Australia, and Sweden, conducted a systematic review to assess the relationship between social functioning and physical frailty in older adults.1 Physical frailty refers to many types of physical deterioration—weight loss, reduced walking speed, and decreased muscle strength. All these things can increase the likelihood of a fall.

The team aimed to describe the prevalence of frailty in people with social vulnerability and vice versa, the bidirectional, longitudinal relationship between frailty and social vulnerability, and how the combination of frailty and social vulnerability is linked to an increased risk of adverse health outcomes. To do so, they searched electronic databases published between January 1, 2001, and April 28, 2023, for observational studies focusing on frailty and social vulnerability.

The 130 eligible studies included participants aged ≥ 18 years. Additionally, eligible measures of social vulnerability included the degree of social support, social isolation, loneliness, social participation, and composite measures (social vulnerability index or social frailty index).

The team selected studies from 27 countries, and 9 studies included participants from multiple countries. Sample sizes ranged from 70 – 27,468 participants, and the mean age ranged from 52 – 90 years.

The study found, when people are frail, they are less likely to engage in social interactions, which can cause them to lose social contacts and create loneliness. Likewise, research showed the relationship can be reversed: a decrease in social contact may lead to frailty.

Cross-sectional studies showed frailty was linked to increased levels of loneliness, increased social vulnerability index, and reduced social participation. Although 1 study found no significant association between social frailty and physical frailty, a larger study revealed a greater prevalence of social frailty in participants with physical frailty (32.2%) compared to patients with without physical frailty (12.3%).

Two studies adjusting for age, sex, socioeconomic position, and marital status, found increased odds of frailty linked to overall social isolation (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.4 – 4.4) or social isolation from wider social networks (OR, 3.06; 95% CI, 1.66 – 5.64). However, frailty was not associated with social isolation from immediate family (OR, 1.34; 95% CI, 0.75 – 2.40).

Many studies found frailty was linked to low social support, however, 8 of 28 studies found no significant association and 1 study found a negative association between frailty and low social support. The studies that showed no association between frailty and social support assessed the availability of support and not perceived adequacy of support.

Studies also showed a significant association between frailty and social vulnerability, and 1 study demonstrated the frailty and social vulnerability index was greater for women (correlation coefficients 0.24 and 0.47) than for men (0.13 – 0.37).

On top of frailty, older adults may experience both a decline in social and mental functioning. Hanlon stressed the importance of acknowledging all these areas of functioning.

“Loneliness…is not an easy problem to solve,” Hanlon said.2 “However, there is more and more knowledge available about possible effective interventions, including activities that support older people to increase their social connections."


  1. Hanlon P, Wightman H, Politis M, et al. The relationship between frailty and social vulnerability: a systematic review. Lancet Healthy Longev. 2024;5(3):e214-e226. doi:10.1016/S2666-7568(23)00263-5
  2. Loneliness Increases The Risk of Health Deterioration in Older Adults. EurekAlert! February 29, 2024. Accessed March 8, 2024.