How social inequality causes biological harm
Long before we can walk or ride a bike, our health is being shaped in countless ways by circumstances beyond our control. It starts in the environment in which your grandmother - your mother’s mother - was born, lived and became pregnant. This grandmother nurtured your mom, along with the egg inside your mom’s ovary that became you. Her health was influenced and shaped by her surroundings, just like yours is. That’s how we adapt to the world we’re born into.
Except now we're facing an epidemic of chronic disease that makes us question what is happening in our environments. Looking at the places and circumstances in which people are born, live, work, gather and age, we see huge differences in health outcomes from state to state, and even neighborhood to neighborhood. Not surprisingly, those who are born into wealthier communities with more resources live longer, healthier lives. They aren’t exposed to the kinds of conditions that other communities live with daily, such as unsafe housing, food deserts, busy highways or crime. Social and environmental conditions are powerful predictors of health and disease. In fact, up to 80% of our health is shaped by these conditions, collectively called the “Social Determinants of Health”. What we are now learning is exactly how and why that happens, on a biological level.
DOHaD explains how adversity creates disease risk
The Developmental Origins of Health and Disease (DOHaD) research explains the importance of the first 1,000 days - from conception to a child’s second birthday. This is a time of vulnerability, when good nutrition and care for mothers, infants and toddlers is critical for the long-term health of the child, the mother and for the next generation.
In the womb, there are specific time periods when each organ and bodily system develops. During these time periods, developing organs and systems can be affected and forever changed by exposures to toxic stress, poor nutrition or environmental pollutants. Depending on the length and timing of these stressors, they can create biological changes that increase the baby’s chances of developing chronic diseases as an adult.
For example, when faced with poor nutrition, a baby in the womb may make “trade-offs” by funneling available nutrients to essential organs like the heart and brain. A trade-off might mean the developing baby uses up available nutrients to protect the brain, at the expense of the pancreas or kidneys. That trade-off means the kidneys or pancreas become vulnerable to disease in adulthood because those organs were compromised in the womb. What was a survival tactic in the womb became a vulnerability later in life. These trade-offs make a person more susceptible to developing chronic diseases like high blood pressure, chronic kidney disease, Type 2 diabetes and others.
The science of DOHaD explains the biology of why we have a modern epidemic of chronic disease, by making a clear connection to the root causes in early development.
Connecting the dots
Adversity can create actual, biological changes in utero - and during infancy and early childhood. These changes create risks that can transfer to the next generations, unless the cycle is broken. Communities experiencing inter-generational trauma and adversity have more chronic diseases. COVID-19 made this very clear. This ongoing adversity has created an epidemic of underlying conditions and susceptibility to chronic disease in the same communities where COVID-19 has been so deadly.
The consequences of inequality affect us all. Addressing the underlying social, economic and environmental inequities in society is the key to solving the epidemic of chronic disease. This is because the stressors of adversity have very real-world consequences for public health. Everyone should have opportunities to make personal choices that lead to a long and healthy life, regardless of where they live and who they are.