Children from poorer backgrounds are more likely to experience biological disadvantages such as ageing faster than their more affluent counterparts, according to a study.
Academics at Imperial College London looked at data from 1,160 children aged between six and 11 from across Europe, for thestudypublished in the Lancet. The children were scored using an international scale of family affluence, which is based on a number of factors including whether a child had their own room and the number of vehicles per household.
Children were split into groups of high, medium and low affluence groups, and blood samples were used to measure children’s average telomere length in white blood cells, while the stress hormone cortisol was measured from urine.
Telomeres are structures found within chromosomes that play an important role in cellular ageing and DNA integrity, and their degradation is linked to ageing. Telomeres become shorter as humans age.
Previous studies have suggested a link between telomere length and chronic diseases, and that acute and chronic stress can reduce telomere length.
The study found that children from the high affluence group had telomeres 5% longer on average compared with children from a low affluence group. Girls were found to have longer telomeres than boys, by an average of 5.6%, while children with a greater body mass index (BMI) had shorter telomeres by 0.18% for each percentage increase in fat mass.
Children from the medium and high affluence groups had cortisol levels between 15.2% and 22.8% lower than children from the low affluence group.
The authors acknowledged the study had some limitations in that the children analysed were not from families living in poverty, and that the study should not be interpreted as showing a link between affluence and “quality” of genes, but rather showing the indirect impact of environment on a known marker of ageing and long-term health.
Dr Oliver Robinson, from Imperial’sschool of public healthand 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.”
Robinson added: “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.”
Kendal Marston, from Imperial’s school of public health and the 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.”