In the January/February 2008 interview with Ichiro Kawachi, a professor of social epidemiology at the Harvard School of Public Health, (full article here) Dr. Kawachi discussed his research linking inequality to public health problems.
An article in Monday’s Washington Post discusses the disturbing findings of studies showing the potentially harmful links between poverty and mental and physical health issues, beginning in childhood.
Children raised in poverty suffer many ill effects: They often have health problems and tend to struggle in school, which can create a cycle of poverty across generations.
Now, research is providing what could be crucial clues to explain how childhood poverty translates into dimmer chances of success: Chronic stress from growing up poor appears to have a direct impact on the brain, leaving children with impairment in at least one key area — working memory.
“There’s been lots of evidence that low-income families are under tremendous amounts of stress, and we know that stress has many implications,” said Gary W. Evans, a professor of human ecology at Cornell University in Ithaca, N.Y., who led the research. “What this data raises is the possibility that it’s also related to cognitive development.”
When the researchers analyzed the relationships among how long the children lived in poverty, their allostatic load and their later working memory, they found a clear relationship: The longer they lived in poverty, the higher their allostatic load and the lower they tended to score on working-memory tests. Those who spent their entire childhood in poverty scored about 20 percent lower on working memory than those who were never poor, Evans said.
“The greater proportion of your childhood that your family spent in poverty, the poorer your working memory, and that link is largely explained by this chronic physiologic stress,” Evans said. “We put these things together and can say the reason we get this link between poverty and deficits in working memory is this chronic elevated stress.”
McEwen said the findings are consistent with earlier research in animals and brain imaging studies in people indicating that the body’s response to stress, such as chronically elevated levels of cortisol, can adversely affect the brain, including the regions involved in working memory.
The findings indicate that education standards and other government policies that aim to improve poor children’s performance in school should consider the stress they are experiencing at home, Evans said.
“It’s not just ‘Read to our kids and take them to the library,’ ” he said. “We need to take into account that chronic stress takes a toll not only on their health, but it may take a toll on their cognitive functioning.”