Epigenetics study finds that children born during the historic recession have markers of accelerated ageing later in life.

The worst recession in US history shaped how well people would age — before they were even born. Researchers have found1 that the cells of people who were conceived during the Great Depression, which lasted from 1929 to 1939 and, at its height, saw about 25% of the US workforce unemployed, show signs of accelerated ageing.

The study authors measured these changes in the cells’ epigenome — the collection of chemical markers attached to DNA that determines when, where and by how much genes are expressed in each cell. And they think the pattern of markers that they uncovered could be linked to higher rates of both chronic illness and death.

The work, published on 8 November in the Proceedings of the National Academy of Sciences1, adds to a cache of studies indicating that exposure to hardship such as stress and starvation during the earliest stages of development can shape human health for decades. The findings highlight how social programmes designed to help pregnant people could be a tool for fighting health disparities in children, says co-author Lauren Schmitz, an economist at the University of Wisconsin–Madison.

Although the study is far from the first to link big historical events to changes in the epigenome, the fact that the signal appears in data collected from people in their seventies and eighties is “mind-blowing”, says Patrick Allard, an environmental epigeneticist at the University of California, Los Angeles.

“It’s definitely something that will make its way into the textbooks,” he says...

...The alterations made during this key window can last a lifetime. In 2008, researchers found2 that people conceived during a famine in the Netherlands at the end of the Second World War had different epigenetic markers compared with siblings born outside this time frame. Those born during the famine had higher rates of metabolic illness later in life, leading scientists to suspect that their exposure to malnutrition during early development permanently shaped how their bodies processed food3.

Since then, a slew of animal studies have linked early exposure to pollutants, stress and poor diet to a wide variety of epigenetic alterations that can shape everything from hair colour to brain development4,5. But only a handful of studies have succeeded in finding these trends in humans, says Ainash Childebayeva, a biological anthropologist at the Max Plank Institute for Evolutionary Anthropology in Leipzig, Germany.

...Nonetheless, “these kinds of studies are really important because they highlight how early development matters for health and disease outcomes later in life”, she (Chilebayeva) says.

Although both health care for pregnant people and economic theory have evolved since the 1930s, Schmitz thinks that studies such as this one can shed light on societal issues today. For instance, earlier this year, the US Supreme Court revoked the federal right to an abortion. Decades of research have shown that people who are denied abortions are more likely to experience financial hardship after an unwanted pregnancy than are those who can access abortions...