A new study in the International Journal of Epidemiology suggests that whether children are brought up in affluent or poverty-stricken homes affects the epigenetics of their DNA, reports New Scientist's Andy Coghlan. Children in rich and poor households have similar sets of genes, but their environment can dictate which genes are switched on or silenced, Coghlan says. "They may be protective responses, and the payoff is surviving a threatening childhood," co-author Marcus Pembrey from the University of Bristol tells Coghlan. Pembrey and his team studied 40 men born in 1958, half rich and half poor, and took blood samples from them when they were 45. "Focusing on … promoter regions, which turn genes on or off, the team examined more than 20,000 sites throughout the genome. They found patterns that varied with the wealth or poverty of the men's childhood homes," Coghlan says. Methylation levels were most significantly varied in the men raised in poor homes, compared to the others. The team doesn't know when the methylation occurred, as the samples were taken from the participants when they were middle-aged. But the paper does strengthen the idea that the environment children are raised in affects their health, the researchers add.