Cash gifts to low-income mothers slowed a DNA marker of aging pace in their young children

Growing up poor is linked with worse health across life, and researchers have long asked whether giving families more money early on could change that. Baby’s First Years, a randomized trial in four US cities, tests the question directly by giving mothers with low incomes unconditional cash every month from their child’s birth.

The latest results, published in Nature Human Behaviour, looked at DNA markers in saliva when the children were 4. Children in families that received $333 a month scored slightly lower on a measure that estimates the pace of biological aging than children in families that received $20 a month. The difference was small, and what it means for health is not known.

What the cash transfer trial had already found

The trial recruited mothers from postpartum wards in 12 hospitals in Omaha, Minneapolis and St Paul, New Orleans and New York. Mothers were randomly assigned to receive either a high-cash gift ($333 per month) or a low-cash gift of $20 a month on debit cards, with no conditions on how the money was spent.

Early results drew wide attention. A 2022 study in PNAS (Proceedings of the National Academy of Sciences) reported that infants in the high-cash gift group showed more power in high-frequency bands of brain activity at age 1. That pattern has been linked in other research with later thinking skills, although the strength of the result depended on how the data were analyzed.

Other outcomes were flat. A 2025 report in JAMA Pediatrics, covering 1,000 families after four years, found that payments totaling about $15,000 did not improve maternal mental health, maternal or child BMI (body mass index), or maternal report of children’s health.

What the DunedinPACE aging measure is

DunedinPACE estimates the pace of biological aging, meaning how fast the body appears to be aging, from chemical tags on DNA known as methylation. It was developed in the Dunedin Study, which follows a group of people born in New Zealand in 1972 and 1973, by tracking decline in 19 indicators of organ-system integrity over two decades.

In adults, faster DunedinPACE scores were associated with morbidity, disability, and mortality, meaning illness, disability and death, and were higher in young adults who had experienced adversity as children. The trial measured it in saliva from 4-year-olds, far from the adults in whom it was developed.

What the cash gifts did to the DNA aging markers

In the new analysis, 313 children in high-cash families and 423 in low-cash families had saliva samples. Both DNA measures were registered in advance as secondary outcomes, which guards against picking favorable results after the data are in. As the researchers had predicted in advance, children in the high-cash group had lower DunedinPACE scores, by 0.17 standard deviations. A standard deviation is the typical spread of scores, so this is a small shift. Because families were randomly assigned, the difference can be attributed to the cash rather than to other differences between families.

A second marker, Epigenetic-g, estimates cognitive ability from DNA methylation. The researchers found no evidence that higher cash gifts increased children’s Epigenetic-g, although the score did correlate with the children’s brain activity. For mothers, there was no evidence that the cash gift had an impact on these epigenetic indices.

What the DNA aging finding cannot tell us

The authors are explicit about the gap. They write that it remains unknown whether the effect persists, or how it relates to children’s behavior and health.

DunedinPACE was built to track aging in adults, and was designed as a blood test, while the trial used saliva. A lower score at 4 does not show that these children will be healthier or live longer. The result was one of several secondary outcomes, and its margin was not far from what chance could produce. The trial’s other outcomes so far, including mothers’ mental health and children’s overall health, showed no differences.

The JAMA Pediatrics authors offered several possible reasons for those flat health results. One is that impacts of early childhood income may not appear until later in life. Another is that an 18% rise in income may be too small to overcome the other pressures that come with poverty.

What this adds to research on cash and child health

Baby’s First Years is one of the few randomized tests of giving families money with no strings attached, and the new result suggests a measurable biological signal in children after four years of cash. Randomized evidence on how income shapes biology in early childhood is rare, which is part of why the trial draws attention.

Whether that signal predicts anything about the children’s health is the question later follow-up will need to answer. The payments continued for the first six years of the children’s lives, beyond the age-4 point measured here.