How do we eliminate the contributors to toxic stress that lead to negative health outcomes?

Lesson Learned

To eliminate intergenerational poverty, we have to address the root causes of the problem. We must reduce the need for treatment interventions by ridding our neighborhoods of the sources of toxic stress that lead to those interventions being required in the first place.

The social environment into which we are born is deeply influential on neurological and physiological developmental outcomes.

The initial work on the relationship between sources of toxic stress and neurological development—the CDC/ Kaiser Permanente Adverse Childhood Experiences (ACE) Study being a noteworthy effort—focused on the impact of trauma on childhood development. These sources of trauma included psychological, physical, or sexual abuse, violence against the mother, or living with household members who were substance abusers, mentally ill or suicidal, or ever imprisoned. What the research shows is that children with exposure to multiple sources of these types of trauma have much higher risk for adverse health effects including maladaptive coping skills, poor stress management, unhealthy lifestyles, mental illness and physical disease.

Additional sources of toxic stress that contribute to the problem include environments with high levels of crime and violence, low-quality housing and public infrastructure, housing instability and high transiency rates, and the lack of access to quality food and nutrition. All of these add up to toxic environments that are hugely influential on life outcomes.

Studies show a direct connection between parental experience and the outcomes for their children: “the parent’s environment during [his/her own] childhood may be more important than the child’s own environment.”

It is not simply the environment into which you are born that impacts the way your genes express themselves. It is also the environment within which your parents were born – and their parents for that matter – that drive how your genes ultimately express themselves.

The impacts of toxic stress manifest themselves across several physiological dimensions, none more important than in neurological development. Exposure to sources of toxic stress leads to the elevation of neuro-endocrineimmune responses resulting in prolonged cortisol activation and a persistent inflammatory state, with failure of the body to normalize these changes after the stressor is removed. It is the failure of these elevated levels to recede normally – given the persistent presence of these threats – that directly impact the neurological architecture of a child’s brain.

Brains are wired in the first years after birth, and brain scans of children living in poverty reveal the extent of this disparity in neural development. By two years of age, obvious gaps in the neurological fabric of children have already developed as a consequence of the physiological impacts of being exposed to sources of toxic stress. This is highly consequential considering most of the resources and formal interventions dedicated to preparing children for school don’t start until a child is four years of age. The science suggests that this is four years too late.

Stress management systems in the brain trigger neurobiological responses that are essential and generally protective, but when activated persistently under circumstances of chronic or overwhelming adversity, they can become pathogenic.

Research demonstrates how neighborhood quality influences health across a variety of dimensions including infant mortality, life expectancy and chronic disease. Residency in distressed neighborhood, for example, is “a strong, independent predictor of diabetes.” Similarly, being raised in a distressed neighborhood will increase a child chance of developing a mental illness.

The information for this Lesson Learned is included in POVERTY AND PLACE: A Review of the Science and Research That Have Impacted Our Work, a white paper that offers an overview of selected research that has informed our thinking as we continue to fight against intergenerational urban poverty.

Purpose Built Communities