Microplastics are everywhere—lurking in the air, water, and everyday products like tea bags and fresh produce. Now, a groundbreaking study has revealed a surprising new source: chewing gum. This research, presented at the American Chemical Society (ACS) spring meeting in 2025, highlights the hidden microplastics in chewing gum, raising concerns about potential health risks. Whether you prefer synthetic or natural gum, the findings suggest that both types release hundreds to thousands of microplastic particles into your saliva with every chew. Here’s what you need to know about microplastics in chewing gum, their health impacts, and how to reduce your exposure.
Microplastics in Chewing Gum: What the Study Found
The study, conducted by researchers at the University of California, Los Angeles (UCLA), and not yet peer-reviewed, aimed to identify new sources of microplastic exposure in consumer products. Led by PhD student Lisa Lowe and principal investigator Sanjay Mohanty, PhD, the team focused on chewing gum—a product many people use daily without considering its composition. According to Lowe, the growing body of research on microplastics in food products inspired the team to investigate whether chewing gum could be a significant contributor to microplastic ingestion.
To explore this, the researchers tested 10 popular chewing gum brands sold in the United States, including five natural and five synthetic varieties (specific brands were not disclosed). Participants were asked to rinse their mouths with deionized water three to five times to establish a baseline for microplastics already present in their saliva. They then chewed each type of gum for four minutes, with some continuing for an additional 20 minutes, while researchers collected saliva samples at various intervals.
The saliva samples underwent a rigorous process to isolate microplastic particles, including shaking, centrifugation, filtration, and digestion. Under a microscope, the researchers discovered that a single gram of gum could release up to 637 microplastic particles. Given that a typical piece of gum weighs between two and six grams, this translates to hundreds or even thousands of microplastics per piece. On average, synthetic gums released 104 microplastics per piece, while natural gums released 96—showing that both types are equally concerning.
The microplastics identified had an average size of 82 micrometers, with 56% of particles smaller than 50 micrometers. Particles smaller than 20 micrometers were difficult to detect, meaning the actual number of microplastics could be even higher. The study also estimated that if a person chews 160 to 180 pieces of gum annually, they could ingest around 30,000 microplastics each year from gum alone.
Interestingly, the release of microplastics peaked within the first eight minutes of chewing, with 94% of particles released during this time. After this initial burst, the rate of release slowed and eventually plateaued, even with extended chewing up to 20 minutes. This suggests that chewing gum for longer periods doesn’t significantly increase microplastic exposure beyond the initial phase.
Why Does Chewing Gum Contain Microplastics?
Chewing gum’s unique texture and elasticity come from polymers—chemical compounds that give gum its chewability and cohesiveness. In synthetic gums, these polymers often include polyethylene terephthalate (PET), polystyrenes, and petrochemical substances like synthetic rubber and polyvinyl acetate. Natural gums, typically made from plant-based materials, were found to contain polyolefins—a type of polymer commonly used in food packaging—which accounted for up to 50% of the microplastics identified.
Sanjay Mohanty emphasized a key difference between gum and other food products when it comes to microplastic contamination. While most research focuses on microplastics from packaging (e.g., tea bags or water bottles) or manufacturing processes, gum is unique because “the food itself is the plastic.” In other words, the very composition of chewing gum makes it a direct source of microplastic exposure, rather than an incidental one.
Health Risks of Microplastics: What Science Says
Microplastics are tiny polymer fragments that don’t break down easily, allowing them to accumulate in the environment and the human body. Scientists have detected microplastics in various parts of the body, including the lungs, bloodstream, placenta, brain, and intestines. While the full extent of their impact on human health is still under investigation, the evidence so far is concerning.
Lisa Patel, MD, a clinical associate professor of pediatrics at Stanford Medicine, explained that microplastics can trigger inflammation and damage healthy cells in the body. Research has linked microplastic exposure to a range of health issues, including:
- DNA Damage and Oxidative Stress: Microplastics may cause cellular damage, increasing the risk of long-term health problems.
- Metabolic Disorders: Studies suggest microplastics can contribute to insulin resistance and other metabolic issues.
- Organ Dysfunction: Accumulation in organs like the liver or kidneys may impair their function over time.
- Inflammatory Bowel Disease: Microplastics in the gut have been associated with an increased risk of conditions like Crohn’s disease.
- Cardiovascular Risks: Particles in the bloodstream may elevate the risk of heart disease.
- Reproductive and Neurological Effects: Microplastics have been linked to decreased fertility and neurotoxicity, potentially affecting brain function.
Patel noted that while the long-term effects of microplastics are still being studied, the growing body of evidence suggests they pose a significant health risk. For gum chewers, the direct release of microplastics into saliva means these particles are likely ingested or absorbed through the mouth, adding to the body’s overall microplastic burden.
Should You Stop Chewing Gum to Avoid Microplastics?
The study’s findings raise an important question: should you ditch chewing gum to reduce your microplastic exposure? According to the researchers, the amount of microplastics released by chewing gum is relatively small compared to other sources, such as tea bags or bottled water. However, Lisa Patel recommends reducing gum consumption as a precautionary measure, especially given the uncertainty surrounding microplastics’ long-term health effects.
If you’re not ready to give up gum entirely, there are steps you can take to minimize your exposure:
- Chew for Shorter Periods: Since most microplastics are released within the first eight minutes, avoid prolonged chewing.
- Stick to One Piece: Chewing a single piece for longer rather than reaching for a new piece can reduce the total number of microplastics you ingest.
- Dispose of Gum Properly: Avoid spitting gum onto the ground, as it can contaminate soil and waterways. Synthetic gum takes about three years to degrade, while natural gum breaks down faster but may release microplastics more quickly if swallowed.
- Don’t Swallow Gum: Swallowing gum increases the risk of microplastics accumulating in your digestive system.
Patel also advocates for broader efforts to reduce plastic use in daily life. “The sooner we minimize our plastics use—keeping it only to the uses where we really don’t have good alternatives—the better off we’ll all be,” she said. This includes opting for plastic-free alternatives in food packaging, clothing, and personal care products whenever possible.
The discovery of microplastics in chewing gum is just one piece of a larger puzzle. Microplastics have infiltrated nearly every aspect of our environment, from the deepest oceans to the air we breathe. They’re found in seafood, drinking water, and even the salt we use to season our food. Consumer products like tea bags, plastic bottles, and synthetic clothing are major contributors to microplastic pollution, and now chewing gum joins the list.
The pervasive nature of microplastics makes it nearly impossible to avoid them entirely, but awareness is the first step toward reducing exposure. By making informed choices—such as cutting back on gum, choosing natural products when possible, and supporting policies that reduce plastic production—you can help mitigate the risks to your health and the environment.
The UCLA study on microplastics in chewing gum sheds light on a hidden health risk in a product many of us take for granted. With hundreds to thousands of microplastic particles released into your mouth with every chew, gum is a direct source of exposure that could contribute to inflammation, metabolic disorders, and other health issues over time. While the amount of microplastics from gum is small compared to other sources, reducing your consumption and taking steps to limit overall plastic use can help protect your health.
As research into microplastics continues, staying informed about their presence in everyday products like chewing gum is crucial. For now, consider chewing less, disposing of gum responsibly, and advocating for a future with less plastic pollution. Your health—and the planet—will thank you.