How chemical exposure early in life is like a ticking time bomb

ORLANDO — Being exposed to a chemical early in life can be a bit like a choose-your-own-adventure book: Some things that happen early on may hurt you later, but only if you make certain choices, an unpublished study in mice suggests.

Mouse pups were exposed to the chemical bisphenol A (BPA) for only five days after birth, a crucial time during which mices livers develop. BPA, once common in plastics, has been linked to a host of health problems in people, from diabetes to heart disease (SN: 10/11/08, p. 14). But depending on diet as adults, the mice either grew up to be healthy or to have enlarged livers and high cholesterol.

As long as the BPA-exposed mice ate mouse chow for the rest of their lives, the rodents remained healthy, molecular biologist Cheryl Walker of Baylor College of Medicine in Houston reported April 7 at the 2019 Experimental Biology meeting. But researchers switched some BPA-exposed mice to a high-fat diet as adults. Those mice had larger livers, higher cholesterol and more metabolic problems than mice who ate a high-fat diet but were not exposed to BPA as pups, Walker said.

BPA exposure immediately altered epigenetic marks at more than 5,400 genes, including 3,000 involved in aging. Epigenetic marks are chemical tags on DNA or on histones — protein around which DNA winds in a cell — that doRead More – Source