Economic disadvantage leaves a biological imprint on children which could last throughout their lifetime, reducing their quality and length of life.
These are the findings of a study of more than 1,000 European children led by researchers at Imperial College London. The research finds evidence that the impacts of socioeconomic status can be seen in the blood cells of children, with those from less privileged backgrounds having shorter telomeres – an established biomarker for ageing.
The analysis, by an international team, is the largest to date to look at the impact of economic status on ageing trajectory of children.
According to the researchers, this early biological imprint could set disadvantaged children on an ageing trajectory which may put them at greater risk of disease in later life and early death, compared to their more affluent peers.
They explain the findings highlight an urgent need for public health policies to level the playing field and protect children's development and lifelong health.
The research, supported by funding from UK Research and Innovation (UKRI), European Commission's Horizon 2020 and others, is published in the journal Lancet eBioMedicine.
Dr Oliver Robinson, from Imperial's School of Public Health and senior author of the study said: "Our findings show a clear relationship between family affluence and a known marker for cellular ageing, with potentially lifelong patterns being shaped in the first decade of a child's life.
"It means that for some children, their economic background may put them at a biological disadvantage compared to those who have a better start in life. By failing to address this, we are setting children on a lifelong trajectory where they may be more likely to have less healthy and shorter lives."
Unequal start
Health inequalities are a key driver of public health outcomes. It is well established that social and economic factors can influence people's current and future risk of disease as well as the quality and length of their lives, and long-term trends can be established in childhood.
In the latest study, the researchers set out to investigate if different ageing trajectories linked to socioeconomic status could be detected in childhood, using telomeres as a biomarker.
For some children, their economic background may put them at a biological disadvantage compared to those who have a better start in life. Dr Oliver Robinson School of Public Health
Telomeres are repeating sections of genetic code which form protective caps at the end of our chromosomes – like the ends of a shoelace. Their degradation is linked with ageing, with telomeres shortening as we get older, so they are a measurable marker of biological ageing.
Several studies have shown links between telomere length and chronic diseases in later life and early mortality.[1] Previous studies have also shown that acute and chronic stress can reduce telomere length,[2] and have demonstrated links between level of affluence and exposure to stressors.[3] However, the association between affluence, stress and telomere length in children is less well characterised.
The team looked at data from 1,160 children aged 6 to 11 years old in six European countries (UK, France, Spain, Greece, Norway and Lithuania).[4] Children were scored using an international scale of family affluence[5] – based on numerous factors, such as whether a child had their own room and the number of vehicles per household.
Based on the scores, children were split into high, medium and low affluence groups. The team used blood samples to measure children's average telomere length in white blood cells. They also analysed urine samples collected from cohorts to measure levels of the stress hormone cortisol.
Affluence and telomeres
The analysis found that children from the high affluence group had telomeres 5% longer on average compared to children from the low affluence group. Girls were found to have longer telomeres than boys (an average of 5.6%). Children with greater body mass index (BMI) also had shorter telomeres (by 0.18% for each percentage increase in fat mass).
The researchers found the relationship between affluence and telomere length was also largely independent of known confounding factors, including adjusting for diet, parental smoking and body mass index.
Our study...demonstrates a link between affluence and telomere length, which we know in adulthood is related to lifespan and health. Kendal Marston School of Public Health
Children from both the medium and high affluence groups had lower cortisol levels than children in the low affluence group (between 15.2% to 22.8% lower). However, the researchers were unable to show a direct link between cortisol levels and telomere length – meaning they weren't able to demonstrate that cortisol is the mechanism by which telomere length is shortened.
Kendal Marston, from Imperial's School of Public Health and first author of the study said: "We know that chronic exposure to stress causes biological wear and tear on the body. This has been demonstrated in animal studies at the cellular level – with stressed animals having shorter telomeres.
"While our study couldn't show that cortisol was the mechanism, it does demonstrate a link between affluence and telomere length, which we know in adulthood is related to lifespan and health. It may be that children from less affluent backgrounds are experiencing greater psychosocial stress. For example, they may be sharing a bedroom with family members, or they may not have the resources they need for school – like access to a computer for homework."
The authors highlight a number of limitations to the study, including that they captured relative rather than absolute length of telomeres and the limited range of economic backgrounds captured. They also sampled cortisol from urine, rather than hair, which could be used to give a longer-term view of cortisol levels. They explain that future studies could further explore the links in different populations and a wider socioeconomic range, as well as take into account other potential contributing factors such as dietary intake.
Dr Robinson added: "We must be clear that our study should not be interpreted as showing any link between affluence and any measure of the 'quality' of genes; rather it shows the indirect impact of environment on a known marker for ageing and long-term health.
"Our work suggests that being from a low affluence background is causing additional biological wear and tear. For children from the low affluent group this may be equivalent to approximately 10 years of ageing at the cellular level, compared to children from high affluence backgrounds.
"It's also important to highlight that the children we studied weren't from families in poverty, so the small impact we observed could be amplified even further when the affluence gap is widened. Overall, it highlights the need to ensure we have public health policies in place to reduce health inequalities and give all children the best start in life."
The study population included children participating in the European population-based HELIX exposome cohort. This was comprised of six ongoing longitudinal population-based birth cohorts from different European countries: Born in Bradford, UK; EDEN cohort, France, INMA cohort, Spain; Kaunas KANC cohort, Lithuania; MoBa cohort, Norway; and RHEA cohort, Greece.
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'Associations of family affluence with cortisol production and telomere length in European children' by Kendal Marston, Chung-Ho E. Lau, Sandra Andrusaityte, et al. is published in Lancet eBioMedicine. DOI: 10.1016/j.ebiom.2025.105793
[1] Findings from UK Biobank data found shorter telomere length was linked with increased disease risk. (Schneider et al. 2022.) https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2788295
[2] Findings from a review and meta-analysis found chronic stress was linked with shorter telomere length. (Mathur et al. 2016.) https://www.sciencedirect.com/science/article/pii/S088915911630023X?via%3Dihub
[3] The Environment of Poverty: Multiple Stressor Exposure, Psychophysiological Stress, and Socioemotional Adjustment (Evans and English, 2003) https://doi.org/10.1111/1467-8624.00469
[4] UK children were recruited via the Born in Bradford cohort - https://borninbradford.nhs.uk/
[5] Researchers used the international Family Affluence Scale. Scores were based on four questions covering car ownership, sharing of children's bedrooms, frequency of holidays and computer or tablet ownership.
