https://www.statnews.com/2024/04/04/climate-change-driving-immune-health-problems/
How climate change is driving a global epidemic of immune health problems, and how to stop it
Many of the effects of climate change play out at a very large scale: Heatwaves that grip entire continents. Flooding that submerges vast swaths of island nations and continental coastal areas. Other effects are far less visible because they’re taking place inside people’s bodies.
That doesn’t make them any less dangerous.
Diseases linked to problems in immune health have been steadily rising over the past few decades. Nasal allergies in children more than doubled from 2012 to 2022. Food allergies, which can be deadly, have also spiked. The global prevalence of rheumatoid arthritis has jumped 14% since 1990. Young people are increasingly vulnerable to colorectal cancer.
To be sure, climate change isn’t the only culprit here: diets heavy in ultra-processed foods, lack of exercise, high levels of stress, and improved testing all likely contribute to rising disease rates. Yet there is also strong evidence, at both the biological and the epidemiological levels, that the environment plays a crucial role in the rise of immune-mediated diseases. As I and a group of colleagues from the U.S. and Europe just reported in Frontiers in Science, climate-driven stressors are driving immune dysregulation at a scope that has contributed to an increase in immune-mediated diseases.
As a physician and a scientist, I believe this epidemic of immune disease must be treated at its source. And that includes tackling climate change.
Climate change derails the human immune system in two keys ways: it breaks down the body’s defenses and also prevents the body from rebuilding them.
Consider the wide array of irritants that climate change routinely brings into communities all around the world. Wildfires release dangerous quantities of tiny soot particles into the air. Flooding dumps industrial chemicals into waterways, and often leaves mold spores sprouting in homes. Unusually warm springs boost the production of ragweed and other pollens. All these exposures damage the structures that have evolved to protect humans from infection, including the skin and the mucous membranes of the gut and lungs.
How does climate change make it harder to build strong immune systems in the first place? Humans need nutritious diets and exposure to a vast array of microbial, fungal, plant, and animal species to train and sustain a robust immune system. All of that is under threat with climate change. Warmer climates irrevocably alter ecosystems, forcing species to move or become extinct. For the humans left behind, fewer interactions with diverse species means a less resilient immune system.
Extreme weather has also destroyed crops and livestock in many parts of the world, leading to an alarming rise in hunger and famine. Even when crops do grow, they may not be as nutritious: food staples such as wheat, corn, rice, and soy lose significant nutrient content when exposed to high levels of carbon dioxide in the atmosphere. Malnourishment also prevents healthy immune system development.
The impact of all these stressors is visible at the cellular level. Scientists have traced the impact of many exposures through cascades of chemical interactions that damage the body’s protective barriers and disrupt the delicate balance of the immune system. In many cases, this actually activates the body’s inflammatory response, and leaves it on, even when it should be turned off. Such persistent inflammation fuels an array of diseases, including cancer.
Scientists understand why more and more of the world’s people are experiencing higher rates of immune-mediated diseases. The question now is whether anything can be done about it.
Fortunately, the answer is an unequivocal yes.
https://www.statnews.com/2024/04/04/climate-change-driving-immune-health-problems/
p1