Itโs a truth weโve become increasingly aware of that we live in a world saturated with plastic. These fossil-fuel-derived particles, known as microplastics (MPs) when they are smaller than 5 mm, are truly ubiquitous. We know weโre drinking, eating, and even inhaling them daily. Consequently, scientists have detected them in places we never expectedโfrom our brains and placentas to our reproductive organs and, yes, even our poop.
But prepare for a discovery that might send a shiver down your spine (literally): researchers have now found these problematic pollutants deep within our bones.
Unknown Threat to Skeletal Health
Bones might seem like sturdy, impenetrable structures, but they are constantly alive, being rebuilt by cells that add and remove tissue. When this delicate system is disturbed, bone strength fades, and the risk of fracture climbs.
A recent, comprehensive review of 62 scientific studies, published in Osteoporosis International, strongly suggests that microplastics and even smaller nanoplastics are impacting our skeletal health in multiple, troubling ways.
How do these tiny fragments reach such a secluded spot?
Plastic particles enter our bodies through air, water, and food. Once inside, the smaller fragments can travel via the bloodstream and lodge in various tissues. Our skeletal system is highly vascular, meaning it has a rich network of blood vessels that can move these circulating particles into the very areas where bone-building and bone-removal cells operate.
Medical scientist Rodrigo Bueno de Oliveira, coordinator of the Laboratory for Mineral and Bone Studies in Nephrology (LEMON) at the State University of Campinas in Brazil, points out that a significant amount of research indicates that microplastics can reach deep into bone tissue, such as bone marrow, and potentially cause disturbances in its metabolism.
The Science of Deterioration
The concern here isn’t just that the plastic is present; itโs what it does once it settles in the bone tissue and bone marrowโthe soft interior where blood and stem cells form.
Studies utilizing human bone tissue cells in a laboratory setting (in vitro studies) have shown alarming results:
- Impaired Cell Function: Microplastics impair cell viability, accelerate cell aging (senescence), and alter cell differentiation.
- Inflammation: They also promote inflammation within the bone cells.
- Disrupted Balance: The review highlights shifts in cell behavior essential for strength. Specifically, the balance appears to tilt towards osteoclastsโthe cells responsible for removing old bone through a process called bone resorption. Too much bone removal leaves the skeleton more fragile over time.
- Stem Cell Interference: Even the versatile mesenchymal stem cells found in bone marrow may be shifting away from becoming bone-forming cells when exposed to certain plastic particles.
In animal models, these adverse effects observed were so severe that they “culminated, worryingly, in the interruption of the animals’ skeletal growth”.
The Link to Osteoporosis
While these precise findings may not translate exactly to human bones, the implications are serious, especially considering the current global health trends. There is an increasing global prevalence of osteoporosis, a condition that makes bones brittle and prone to fractures.
Researchers strongly suspect that microplastics could be a contributing factor to this rising tide of fragility, alongside well-known risks like drinking and general aging. As Mr. Bueno de Oliveira explains, adding cellular stress from microplastics could magnify an existing small problem, especially for those already at risk.
This is a major issue on a population level: the International Osteoporosis Foundation (IOF) projects that osteoporosis-related fractures are set to increase by an estimated 32% by 2050. Generating evidence to suggest that microplastics are a potential, controllable environmental cause could be crucial for addressing this projected increase in fractures.
What Can We Do?
This danger remains “underrecognized,” yet the scale of plastic production is staggeringโwe produce at least 400 million metric tons of plastic each year. This manufacturing process itself contributes significantly to climate change, generating 1.8 billion metric tons of greenhouse gases annually.
Researchers have been calling for years for more resources to investigate the full scope of these petrochemical pollutants on our bodies.
In the meantime, experts suggest that we can take small steps to somewhat reduce our personal exposure. This includes:
- Filtering drinking water.
- Limiting the use of plastic products, such as synthetic clothing and plastic drink bottles.
- Maintaining known healthy practices like physical exercise and a balanced diet to improve quality of life and reduce bone complication risks.
While scientists work to determine how much exposure matters, who is most at risk, and which specific particles are the most harmful, the direct evidence is clear: microplastics are now part of our deepest tissues, and they have the potential to weaken the very structures that hold us up. This is definitely a scientific story to keep watching.
