We usually think of aging as something that catches up with us later in life.
Biologically speaking, however, the story may begin much earlier.
An emerging body of research suggests that growing up poor may speed up biological aging in childhood, adding to the range of effects poverty seems to have on children, some of which could persist for life.
Despite the weight of evidence, though, it’s been difficult to confirm the causal effects of poverty on children’s health, given the huge amount of other factors tangled up with socioeconomic disadvantage.
But one pioneering research project is designed to do just that.
The Baby’s First Years study is an ongoing randomized trial in the US investigating how cash payments given to mothers on a low income affect their children’s health and development as they grow up.
In a new study published in Nature Human Behaviour, scientists analyzed data from the Baby’s First Years project, and the findings suggest that the cash payments given in the trial had a measurable impact on the children’s biological aging, as evidenced by epigenetic markers in their saliva.
While the long-term impacts on these children’s health remain unknown, it’s an important step forward in this field of research – and one that suggests reducing childhood poverty itself could potentially have long-term health benefits.
“The fact that we already see differences in four-year-old children in their biological aging is striking,” says co-author and behavioral geneticist Kathryn Paige Harden from the University of Texas at Austin.
In the Baby’s First Years study, 1,000 mothers with low incomes were randomly assigned to receive either US$333 a month (400 families) or US$20 a month (600 families), with the payments lasting through the first 76 months of the child’s life.
The boost in cash for the treatment group amounted to roughly $4,000 extra for the families each year, representing an approximate 18 percent increase in their annual income.
The broader question is whether that extra cash affects children’s health, alleviating the negative impacts associated with poverty.
In terms of the new study – which specifically focused on biological aging – the results suggest yes.
When the children in the study reached approximately four years of age, researchers collected saliva samples from the children and their mothers, and then analyzed patterns in their DNA.
Their main measure was called DunedinPACE, an epigenetic biomarker designed to estimate the speed of biological aging, based on patterns of DNA methylation.
The results showed that children from families who received the monthly $333 cash gift exhibited a slower epigenetic pace of aging, which was 0.17 standard deviations lower than children in the low-cash group.
That’s a relatively small effect overall, but the fact that it was observable at all is important, the team says.
“Previous research has shown correlational evidence in other studies suggesting that poverty may accelerate epigenetic aging in children, but correlations alone can’t tell us whether intervening can slow that process,” says developmental psychologist Laurel Raffington from the Max Planck Institute for Human Development in Germany.
“So it is notable to see a causal impact of the cash transfers.”
The researchers tested a number of other DNA-methylation measures in the saliva – including Epigenetic-g, a biomarker associated with cognition – but found no clear benefits from the high-cash payments, which also didn’t appear to affect the mothers’ biological aging.
Related: These Babies Grew Up With Strict Sugar Limits. Decades Later, The Results Are Dramatic.
The research team acknowledges there’s a huge amount we still don’t know about what’s happened in this potentially groundbreaking experiment.
The children are only seven to eight years old, after all. They have their whole lives ahead of them.
But there’s a very real chance that the money given to their mothers has done good things for them, and maybe what scientists learn here will one day be able to benefit others in the future too.
“Whether the modest reduction observed here translates into measurable health benefits remains uncertain,” the researchers write in their paper.
“Because accelerated aging accrues cumulative biological costs, economic and health returns may be especially pronounced when cellular aging is decelerated early in life, and even modest reductions may yield outsized public health benefits.
“However, such benefits depend critically on the long-term persistence of this effect, which is currently unknown.”
The findings are reported in Nature Human Behaviour.
This article was fact-checked by Rebecca Dyer and edited by Rebecca Dyer. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know.
