"How the Great Depression shaped people’s DNA"

Though most of the research on the epigenetic connection between famine and genetics has been done on the grandchildren of the Dutch survivors of the Hongerwinter,* the Nazi blockade of supplies to Northern and Western Nazi-occupied Holland in 1944 -45, the famine that started in 1866 Finland was the last natural great starving in Europe, and genetic markers for famine can still be found in the great, great, great grandchildren of those survivors.

I don't know if there have been any epigenetic studies of what Stalin and the communists did in the 1932 - '33 Ukrainian SSR Holodomor, excess mortality of 3.5 to 4 million.

From the journal Nature, November 21:

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.

Epigenetic alterations

In the earliest stages of development, an embryo is a packet of potential, containing genetic instructions to build the molecular components of the body. Over time, however, cells add and remove chemical modifiers known as epigenetic tags to their DNA, and these shape how those cells and their descendants execute the instructions. The tags are influenced by a variety of factors, including hormones, diet and people’s environment....

....MUCH MORE

*To a lesser extent the 1836 famine in Northern Sweden as well.

 

It can be difficult for an outsider to tell what exactly is "the science" in this field, as was mentioned in 2014's "Do Your Grandmother’s Experiences Really Make It Into Your Genes?"  and the outro from 2020's "The Epigenetic Secrets Behind Dopamine, Drug Addiction and Depression":

I'm still trying to get my head around what's real and what's hype in epigenetics. In the introductory riff from "Labor Markets: 'Rural America Needs Triage'" I sound more certain than I actually am.

Some concepts, profound in their simplicity, that policymakers will have to internalize before the human toll of current economics—whether fast suicides by firearms or hanging or slow suicides by opioids, self-medicating with carbohydrates and booze leading to epidemic levels of obesity, cirrhosis and diabetes, from first generation poverty leading to  multi-generational epigenetic DNA methylation of genes linked to depression—the policy wonks have to get the basics down first....