From the Montreal Gazzette:

Early childhood living conditions provoke biological changes in genes leading to DNA “memory” that can last a lifetime, an international study has found.

Experts have already noted that income, education and neighbourhood resources can have a dramatic effect on children’s health, and that a poor socio-economic environment in infancy can translate into a higher risk of adult disease and early mortality.

But a study published online Thursday in the International Journal of Epidemiology suggests that early experience works changes that are far more than skin deep.

The environment of early childhood influences brain and biological development and leaves a “memory” in the genetic code that affects the way genes function, say researchers from McGill University, the University of British Columbia and the UCL Institute of Child Health in London, England.

“Biological embedding” may help explain why health disadvantages linked to a lower socio-economic origin — including obesity, mental health problems, heart disease, diabetes and other chronic illnesses — can last a lifetime even if living conditions improve later.

The team focused on a small sample — 40 men — from the ongoing British cohort study, which has followed 10,000 people born in March 1958 from birth onward.

The team looked at the DNA of men aged 45 who came from one of two economic extremes: children whose fathers were unskilled workers; and those whose dads were company CEOs and Oxford/Cambridge graduates.

“We wanted to sample from the extremes so that if there was an epigenetic (gene) signal, it would be as clear as possible — and that’s in effect what emerged,” said Clyde Hertzman, director of the UBC-based Human Early Learning Partnership and an author of the study.

After looking at control areas of 20,000 genes, researchers found twice as many genetic differences (1,252 changes) in those brought up in wealth and comfort compared to those raised in poor living conditions (545 changes), making a link between the economics of early life and the biochemistry of DNA.

More.

Advertisements