Some of those associations are cumulative, sex-specific and detectable up to decades after exposure. In this blog, we explain how researchers measure biological ageing, what we found and why childhood experiences still leave a mark on the body later in life.
Not everyone ages at the same rate: one person might be 50 years old; another might be 50 years young. Scientists can now estimate how old the body is biologically, independent of chronological age. Our ‘biological age’ can be estimated, for example, using blood-based molecular clocks, frailty indices, telomere length and functional measures like grip strength.
But what makes one person biologically older and some younger? Our research suggests that exposure to adversity and trauma might be part of the answer, including experiences that occurred decades earlier.
What we did
We studied more than 150,000 UK Biobank participants aged 40-69 years, across three studies. Participants self-reported adversity in childhood (e.g., abuse, neglect) and adulthood (e.g., partner violence, financial hardship) and lifetime non-relational trauma (e.g., serious accidents, combat exposure, life-threatening illness).
We examined biological ageing across multiple domains: a metabolomic clock, a metabolomic mortality score, a frailty index, telomere length (the length of repetitive DNA sequences at the end of chromosomes, with telomeres shortening with ageing) and grip strength.
What we found
Across all three studies, individuals who experienced adversity or trauma had older biological ageing profiles.
- Associations were strongest and most consistent for frailty, a measure of age-related health deficit accumulation, with a graded, almost linear pattern: the more types of adverse events, the greater frailty
- Individuals exposed to adversity in both childhood and adulthood had the most pronounced ageing profiles, including a metabolite-based biological age exceeding chronological age and weaker grip strength (Aas et al., BMC Medicine). Abuse was more consistently linked to biological ageing markers than neglect
- The period of adversity exposure mattered differently by sex. Childhood adversity was linked to most biological ageing markers in females; adulthood adversity was more strongly linked in males, particularly for frailty and grip strength (Mutz et al., Aging Cell)
It was not just adversity within interpersonal relationships that was associated with biological ageing. Non-relational traumatic experiences, for example serious accidents, life-threatening illness and combat exposure, were also associated with older biological profiles, with frailty again showing the strongest associations (Hoppen et al., GeroScience).
Associations with telomere length were inconsistent and generally weaker than for other ageing markers. Grip strength findings for non-relational trauma were also mixed: some trauma types, such as combat exposure, were associated with higher grip strength, likely reflecting who is exposed to these events rather than a protective effect of trauma.
Possible contributing factors to increased ageing
Many factors could have an impact on biological ageing such as chronic stress leading to sustained activation of the body’s stress response system, inflammation and cumulative biological wear and tear over time.
Childhood adversity may also increase vulnerability to further adversity in adulthood and shape behaviours such as smoking and physical inactivity that negatively impact health and ageing.
One question that arises is whether frailty, which captures accumulated poor health, is measuring biological ageing or simply reflecting the health consequences of adversity.
This is one reason why examining multiple markers matters: the fact that associations were also observed for metabolomic ageing and, in some analyses, telomere length and grip strength suggests that the link extends beyond the accumulation of poor health alone.
These patterns are consistent with the concept of biological embedding: the idea that social experiences can leave lasting marks on our biology. However, these are proposed contributing factors; our data did not identify these as causes.
Why this research is important
This research strengthens the case for preventing childhood adversity, as the health benefits of prevention may extend decades into later life.Adults exposed to adversity could benefit from support that goes beyond mental health treatment, addressing the long-term biological toll.
Frailty, the measure most strongly and consistently associated with adversity and trauma across all three studies, is modifiable through exercise, nutrition and social connection. That is reason for optimism.