Volunteering, often celebrated for its social and psychological benefits, may also hold profound biological implications. A recent study published in Social Science & Medicine investigates whether volunteering can slow epigenetic age acceleration—a biomarker of biological ageing—and how this relationship varies between retired and working older adults. Using data from the Health and Retirement Study (HRS), the researchers uncover intriguing links between volunteering, retirement status, and biological ageing, opening new avenues for promoting healthy ageing.
Understanding Biological Ageing and Epigenetic Age Acceleration
Biological ageing refers to the physiological changes that occur as individuals grow older, influenced by genetic, environmental, and behavioral factors. Unlike chronological age, which is a mere tally of years lived, biological ageing can differ significantly among individuals. Slower biological ageing often correlates with delayed onset of age-related diseases, better cognitive and physical functioning, and enhanced metabolic, cardiovascular, and immune system integrity.
Epigenetic clocks, which estimate biological age based on DNA methylation patterns, have emerged as powerful tools for studying ageing. Measures like PhenoAge, GrimAge, and DunedinPACE provide insights into how rapidly an individual’s body is ageing relative to their chronological age. Accelerated epigenetic ageing has been linked to higher risks of morbidity and mortality, making it a critical focus for ageing research.
Volunteering as a Potential Intervention
Social participation, especially structured volunteering, has long been associated with health benefits. Previous studies highlight that volunteering can reduce hypertension, chronic inflammation, and stress, while enhancing cognitive function and mental health. It fosters meaningful social engagement, which buffers against stress and promotes overall well-being.
However, the specific impact of volunteering on biological ageing remains underexplored. The current study builds on existing literature by examining whether volunteering slows epigenetic ageing and whether this effect differs for retired and working older adults. Such findings could inform interventions aimed at reducing age-related health disparities.
Study Design and Methods
The researchers analysed data from the HRS, a nationally representative panel study of Americans aged 51 and older. The study included pre-treatment covariates from 2012, volunteer frequency and work status data from 2014, and DNA methylation measures from 2016, resulting in a sample of 2,605 participants.
Key Measures
Volunteering Frequency: Participants reported their annual hours of volunteer work, categorised into five groups: non-volunteers, 1–49 hours, 50–99 hours, 100–199 hours, and 200+ hours.
- Retirement Status: Participants identified as retired or working full-time/part-time in 2014.
- Epigenetic Clocks: Five DNA methylation-based measures—Horvath, Hannum, PhenoAge, GrimAge, and DunedinPACE—were used to assess biological ageing.
- Generalised linear models, adjusted for demographic, socioeconomic, and health-related covariates, were employed to analyse the relationship between volunteering and epigenetic ageing, with stratified analyses by retirement status.
Key Findings
Volunteering Reduces Epigenetic Age Acceleration
- Volunteering, especially at low (1–49 hours/year) and high (200+ hours/year) frequencies, was associated with slower epigenetic ageing. These effects were particularly pronounced in second- and third-generation clocks like PhenoAge, GrimAge, and DunedinPACE, which predict health and longevity outcomes more robustly than first-generation clocks.
- Low-Intensity Volunteering (1–49 hours/year): Associated with significant deceleration in PhenoAge (β = −0.67, p < 0.001), GrimAge (β = −0.21, p < 0.01), and DunedinPACE (β = −0.01, p < 0.001).
- High-Intensity Volunteering (200+ hours/year): Linked to even greater reductions in PhenoAge (β = −0.97, p < 0.001), GrimAge (β = −0.34, p < 0.01), and DunedinPACE (β = −0.02, p < 0.001).
Retirement Amplifies Benefits of Volunteering
The study found that the benefits of volunteering were more pronounced among retired individuals. Moderate levels of volunteering (50–199 hours/year) significantly slowed epigenetic ageing in retirees but not in working adults. For example:
- PhenoAge: Volunteering 100–199 hours/year led to a deceleration (β = −1.92, p < 0.05) among retirees.
- GrimAge and DunedinPACE: Moderate volunteering (50–99 hours/year) was associated with slower ageing (β = −0.98 and β = −0.04, respectively, p < 0.05) only in retirees.
These findings suggest that retirement creates opportunities for older adults to reap greater health benefits from volunteering. Retirees may experience enhanced social engagement, purpose, and mental stimulation through volunteering, which buffer the loss of work-related roles and connections.
Cumulative Volunteering Offers Sustained Benefits
Cumulative volunteering over two years (2012–2014) showed consistent benefits across all epigenetic clocks. Sustained high engagement (200+ hours/year) significantly reduced biological ageing rates, emphasising the importance of long-term volunteer commitments.
Implications for Public Health
Promoting Volunteering as a Healthy Ageing Strategy
The study highlights volunteering as a viable public health intervention to slow biological ageing and enhance quality of life among older adults. Public health initiatives could encourage older adults, particularly retirees, to engage in volunteering by:
- Creating Accessible Opportunities: Providing diverse and flexible volunteer programs tailored to older adults’ interests and capabilities.
- Raising Awareness: Educating communities about the physical, mental, and biological benefits of volunteering.
Integrating Volunteering into Retirement Planning: Encouraging soon-to-be retirees to incorporate volunteering into their post-retirement routines.
Targeting Retirees for Maximum Impact
Since retirees benefit most from volunteering, interventions could focus on this group to maximise health outcomes. Structured programs could address the social and psychological void left by retirement, fostering new connections and purpose.
Future Research Directions
Further studies should explore:
Mechanisms Linking Volunteering and Biological Ageing: Investigating how social interactions, physical activity, and sense of purpose mediate this relationship.
Long-Term Effects: Assessing the impact of volunteering over decades to understand its cumulative benefits.
Diverse Populations: Examining whether these findings hold across different cultural, socioeconomic, and demographic groups.
This study highlights the potential of volunteering to slow biological ageing, particularly for retired older adults. By fostering social connections, physical activity, and a sense of purpose, volunteering offers a holistic approach to promoting healthy ageing. Public health policies and community programs should leverage these insights to enhance the well-being and longevity of older populations, creating a society where ageing is not only inevitable but also meaningful and fulfilling.
The study is published in the journal Social Science & Medicine. It was led by Seoyoun Kim from Department of Sociology, Texas State University.
