Being raised in poverty can have lifelong negative effects on children’s health, increasing their risk of chronic disease in adulthood. But new research suggests one factor that may help protect poor kids from later illness: having a nurturing mother.
Growing up poor is stressful, and chronic stress is known to impact physical health long term. Research finds that poor kids are more likely to develop metabolic syndrome — a collection of risk factors that may lead to Type 2 diabetes, cardiovascular disease and stroke — compared with their wealthier peers, for example.
Unless they have an especially nurturing mother, that is. “If children had lots of maternal warmth, in terms of metabolic syndrome risk, [they looked like they] grew up in households where both parents had advanced degrees,” says study author Gregory Miller, professor of psychology at the University of British Columbia in Canada, using educational attainment as a marker of high social class.
The study examined a sample of 1,215 middle-aged Americans who were part of a larger ongoing research project. The researchers determined participants’ socioeconomic backgrounds based on their parents’ education level and used questionnaires to gauge how nurturing those parents were in childhood.
Overall, kids who grew up poor were 40% more likely to have metabolic syndrome in adulthood — which includes high blood pressure, glucose intolerance and extra fat around the middle — than more privileged children. That elevated risk remained even in poor children who grew up to complete college and raise their socioeconomic status.
But when the effect of parental care was taken into account, the researchers found that the excess risk disappeared. Children who were raised in low-educated families, but whose mothers were nurturing, were no more likely to have metabolic syndrome than kids whose parents had four-year college degrees.
“The true value in this study is the demonstration of the capacity of positive relational characteristics to buffer the known impact of adverse experiences on the developing child,” says Dr. Bruce Perry, a senior fellow of the ChildTrauma Academy, who was not associated with the study. (Full disclosure: Perry and I have co-authored two books.)
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So how does Mom’s love translate into a lower risk of heart disease and diabetes? The answer has to do with how the body reacts to chronic stress, and how parental nurture reduces these physiological changes.
The chronic high stress of growing up poor can alter children’s developmental pathways. One result is changes in levels of cortisol, a key stress hormone. “Cortisol changes the way glucose is regulated. It changes insulin sensitivity and glucose production,” explains Miller. “There are effects on blood vessels, on how elastic they are and on retention of fat in the abdominal cavity. Inflammation also plays a role.” All these factors contribute to the increased risk of metabolic syndrome.
Maternal nurture, in contrast, lowers children’s levels of stress hormones. It can mitigate the damaging effects of having low social status and living in high-crime neighborhoods. “High levels of nurture can teach kids growing up in a dangerous and unpredictable environment that you can trust some people. You don’t have always have be suspicious. You don’t always have to be ramped up and vigilant,” says Miller, noting that a state of high vigilance and mistrust goes hand-in-hand with elevated stress hormone levels.
Studies show that being held and treated kindly lowers kids’ stress. “Giving them that basic sense of security and trust relieves them from this physiological burden that you carry if you are constantly on alert for threat, and worried about someone harming you physically or psychologically,” Miller says.
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“To date most of the studies in this area have focused on adverse experiences, which, of course, are important to understand,” says Perry. “Yet examining adverse experiences only gives an incomplete picture of developmental risk. Examining the nature and timing of adverse experience, as well as potential attenuating factors, such as maternal nurturance, is the only way to develop a sophisticated understanding of the impact of experience on the developing child.”
The study was published in Psychological Science.
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Maia Szalavitz is a health writer at TIME.com. Find her on Twitter at @maiasz. You can also continue the discussion on TIME Healthland’s Facebook page and on Twitter at @TIMEHealthland.