Cumulative Loneliness Could Lead to Higher Mortality Risk

dining out alone

Working from well-established research on the negative health effects of loneliness, University of Michigan researchers set out to investigate whether feeling lonely multiple times over the years leads to more serious illness and a higher mortality risk in mid to later life. They found that, indeed, it did.

“Cumulative loneliness in mid- to later-life may be a mortality risk factor with a notable impact on excess mortality,”

according to the prospective cohort study led by Xuexin Yu, a doctoral student in epidemiology at U-M’s School of Public Health.

According to the US National Poll on Healthy Aging, the percentage of adults between the ages of 50 and 80 who reported feeling isolated increased from 27% in 2018 to 56% in 2020 during the COVID-19 pandemic, and it stayed at 34% in the early months of 2023.

Cumulative Loneliness

Researchers observed that those who reported more periods of loneliness had a substantially greater mortality risk than those who reported no or fewer moments of loneliness. The researchers analyzed data from over 9,000 individuals in the Health and Retirement Study, which is considered the most credible data source on aging in the United States.

“The focus on cumulative loneliness brings a new contribution to the field of loneliness research,”

said study senior author Lindsay Kobayashi, professor of epidemiology and global health.

The loneliness data was collected during an eight-year period, from 1996 to 2004, and was divided into four categories: never experienced loneliness, experienced loneliness once, twice, or three times, and experienced loneliness three times.

Responses were cross-referenced with individuals’ health and lifestyle data, and social isolation was objectively evaluated at baseline in 1996 and subsequent death risk through 2019.

A Preventable Risk Factor

Even the researchers were taken aback by the findings. The results showed that during the eight-year exposure period, there were 106 excess deaths when loneliness was recorded once, 202 excess deaths when it was reported twice, and 288 excess deaths when it was reported three or more times.

“Loneliness is not a static experience; it is dynamic. So, the eight-year duration of our data on loneliness was a unique part of this study that allowed us to look into cumulative loneliness over time. The numbers surprised me. They strike me as very high because loneliness is preventable. Anytime there are excess deaths due to a modifiable risk factor, it’s too many,”

Kobayashi said.

With life expectancy in the U.S. still at historic lows and loneliness being treated as a global health crisis by the U.S. Surgeon General and the World Health Organization, the study urges prevention:

“Loneliness may be an important target for interventions to improve life expectancy in the United States.”

Big Red Flag

For both younger and older folks, it is vital that loneliness be lessened on a societal basis. Growing worries have been expressed about the possibility that as people age and lose important life responsibilities, retiring from the workforce, loneliness will rise.

“Life expectancy in the U.S. has dropped. That is a particularly big red flag,”

Kobayashi said. She added it’s important to note that living alone or preferring solitude is not necessarily the same as feeling lonely.

“Even those who are socially isolated may not feel lonely. It’s the feeling of loneliness, of needing people and purpose and not getting it, which appears to be bad for health,”

she said.

“As people age, they transition out of meaningful social roles. They need meaningful replacements. Maintaining integration with families is important and can be a big source of meaning in life. We do live in an individualist society and should evaluate our culture’s value of older people to society,”

she explained.

Intervention Suggestions

Kobayashi suggested that age-friendly communities that integrate older residents into urban planning could be additional measures taken to combat the crisis of loneliness.

“There are ways we can make environments accessible, offer places to go and socialize. It’s about the physical design of communities and resources and priorities. It’s about a cultural shift in how we see and portray older people.” Kobayashi said. “Extending work life, especially as Baby Boomers age, could be of benefit. Policy changes are needed to support changes.”

The COVID-19 pandemic has resulted in a loss of community, which these adaptations can help restore.

“This issue cuts across so many parts of society. It really does affect us all,”

she said.


Loneliness is a growing public health concern worldwide. We characterized the association between cumulative loneliness and subsequent all-cause mortality, using data from 9,032 participants aged 50+ in the population-based US Health and Retirement Study (HRS) from 1996 to 2019. Loneliness status (yes; no) was measured biennially from 1996 to 2004, and we categorized the experience of cumulative loneliness over the 8-y period as never, one time point, two time points, and ≥three time points. A multivariable-adjusted age-stratified Cox proportional hazards regression model was fitted to examine the association between cumulative loneliness from 1996 to 2004 and all-cause mortality from 2004 to 2019. Excess deaths due to each category of cumulative loneliness were calculated. Compared to those who never reported loneliness from 1996 to 2004, participants experiencing loneliness at one time point, two time points, and ≥three time points respectively had 1.05 (95% CI: 0.96 to 1.15), 1.06 (95% CI: 0.95 to 1.19), and 1.16 (95% CI: 1.02 to 1.33) times higher hazards of mortality from 2004 to 2019 (P trend = 0.01). These results correspond to 106 (95% CI: 68 to 144), 202 (95% CI: 146 to 259), and 288 (95% CI: 233 to 343) excess deaths per 10,000 person-years, for those experiencing loneliness at each of one, two, or ≥three time points from 1996 to 2004. Cumulative loneliness in mid-to-later life may thus be a mortality risk factor with a notable impact on excess mortality. Loneliness may be an important target for interventions to improve life expectancy in the United States.

  1. Xuexin Yu et al. Association of cumulative loneliness with all-cause mortality among middle-aged and older adults in the United States, 1996 to 2019. Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2306819120