Asked to describe the factors that contribute to overall health, most Americans would likely point to genetics and personal habits like diet and exercise.
But, two new studies add to growing evidence that the environment we live in is at least as powerful a driver of individual health outcomes, genetic codes, or personal efforts to eat well, exercise, and get regular medical care.
Scott Brown, Ph.D., a public health researcher at the University of Miami Miller School of Medicine, turned to NASA satellite imagery rather than a microscope or a DNA sequencer to measure health.
Brown studied Medicare recipients in Miami-Dade County and found that those who live in neighborhoods with more greenery in them, as shown in satellite photos, had fewer chronic conditions.
In neighborhoods with slightly more greenery than average, researchers found 49 fewer chronic conditions per 1,000 people than they did in neighborhoods with slightly less greenery than average.
Put another way, the seniors in the less green neighborhoods aged an average of three years faster than their peers in lusher areas.
Brown hopes the findings will help encourage Miami-Dade to invest in greener neighborhoods.
“Although there is up-front cost of planting trees, there could be long-term benefits in terms of lower disease burden,” he told Healthline.
It wasn’t just luck that determined which neighborhoods had more nature. The number of trees correlated with the average income of the residents.
Brown’s study thus helps answer a pressing public health question: How exactly do people living in poverty in the United States and around the world end up sicker than their more affluent peers, even after researchers account for their limited access to quality healthcare?
Additional greenery offered the biggest health bump in poorer neighborhoods, Brown and his colleagues found. That may be because adding some green space where there is almost none makes a bigger difference than adding more green space to an already leafy neighborhood, Brown said.
Poor Kids Are Sicker, Too
Dr. Christian Pulcini focused on children who had been diagnosed with asthma, ADHD, or autism spectrum disorder (ASD).
The rate of children who have been diagnosed with these disorders has grown more quickly among children from low-income households than among children from higher income households.
Children from low-income households who are diagnosed with asthma, ADHD, or ASD were also more likely to have additional health conditions, including anxiety and depression.
“Poorer kids do have a variety of different factors that could potentially lead to these conditions,” Pulcini told Healthline.
The preliminary findings can’t specify what it is about poverty that leads to chronic conditions. However, Pulcini pointed to a recent policy paper from the American Association of Pediatrics (AAP) that targets “toxic stress,” or “excessive or prolonged activation of the physiologic stress response systems in the absence of the buffering protection afforded by stable, responsive relationships.”
Health research has increasingly suggested that toxic stress in childhood is a lifelong health risk. Poverty isn’t the only cause of toxic stress. But, Pulcini said, few would deny that it is an important cause.
A Higher Priority
The AAP paper suggests that the United States could do more to combat childhood poverty, where it is a bigger problem than in other industrialized countries.
But what help the U.S. government does provide to low-income households, including the disability benefits that Pulcini analyzed, has come under threat in a budget slashing political environment.
“It’s a matter of showing that these kids in poverty with one condition also have other conditions. That would sort of justify them having these funds,” Pulcini said.
Pulcini hopes that, in the absence of more robust social programs for low-income households, doctors can help limit the damage poverty does by examining children with asthma and ADHD for other concurrent conditions.
“Having a conversation with kids who have asthma or ADHD about depression and anxiety and making sure they’re addressed is pretty important,” he said.