Chewing Gum and Microplastic Exposure
Based on current evidence, conventional chewing gum does contain synthetic polymers that are technically microplastics, but the direct health risks from chewing gum specifically remain poorly characterized, with broader microplastic exposure from drinking water, food, and oral healthcare products posing more quantifiable concerns.
Understanding Microplastics in Oral Products
Modern chewing gum is manufactured using synthetic polymers rather than natural rubber bases, making it a source of microplastic exposure through oral contact. However, the evidence base focuses primarily on other oral healthcare products rather than gum specifically:
Oral healthcare products universally contain microplastics, with toothbrushes showing the highest contamination (30-120 particles per brush), toothpaste containing 0.2-0.9% microplastics by weight, and mouthwash contributing approximately 74 billion particles daily across India's population 1, 2
Common polymers identified in oral products include polyethylene (52%), polyamide (30%), polyethylene terephthalate (15%), and polybutylene terephthalate (3%), with fragment shapes (60%) being most prevalent 1
Microplastic particles range from 3.5 μm to over 400 μm in oral healthcare products, with the majority (<100 μm) small enough for potential systemic absorption 2
Health Risk Assessment
The potential health impacts of microplastic exposure remain an area of active investigation with significant knowledge gaps:
Known Exposure Pathways
Drinking water represents a major documented source, with bottled water showing higher microplastic concentrations than tap water, according to the World Health Organization 3
Human tissue accumulation has been confirmed, with lung tissue showing the highest burden (14.19 ± 14.57 particles/g), followed by small intestine (9.45 ± 13.13 particles/g), large intestine (7.91 ± 7.00 particles/g), and tonsils (6.03 ± 7.37 particles/g) 4
Females demonstrate significantly higher microplastic accumulation than males across tissue types (p < 0.05) 4
Potential Toxicity Mechanisms
The physical presence of microplastics can induce immune responses and inflammation, while leaching of plastic-associated chemicals (additives and adsorbed toxins) may cause chemical toxicity, as explained by the American Chemical Society 5, 3:
Particle toxicity occurs through immune system activation when microplastics accumulate in tissues, based on limited animal study data 5
Chemical toxicity results from leaching of plastic additives and environmental contaminants that adsorb to microplastic surfaces 5
Biofilm formation on microplastics may serve as vectors for microbial pathogens 5
Vulnerable Populations
Children and individuals with pre-existing conditions face heightened risk:
Children show higher estimated daily intake values for specific phthalates and related compounds compared to adults, with smaller body size, developing organ systems, and immature metabolic capabilities increasing vulnerability, according to the World Health Organization 6
Dose-dependent effects remain poorly characterized, with current knowledge of exposure levels insufficient to determine safe thresholds 5
Current Evidence Limitations
High-quality data on microplastic exposure levels and health effects remain severely limited, with most research using polystyrene microspheres as model particles that may not accurately represent environmentally relevant microplastics, as noted by the National Academy of Sciences 3:
Standardized detection methods do not exist, making comparison across studies difficult and risk assessment imprecise 5
Human health effects are still unknown despite documented tissue accumulation, with most toxicological data derived from animal models and cell culture studies 5, 7
Environmentally realistic exposure studies are in their infancy, with many unsolved questions regarding actual health risks 7
Practical Risk Mitigation
Given the uncertainty but documented exposure, prudent measures include:
For General Population
Choose filtered tap water over bottled water and run tap water before collection to minimize microplastic exposure, as recommended by the Environmental Protection Agency 3
Use water filtration systems capable of removing microplastic particles 3
Minimize use of plastic-containing oral products when alternatives exist, given the documented contamination levels 1, 2
For Vulnerable Populations
For children and individuals with compromised health, exercise heightened caution by limiting exposure to known microplastic sources:
Prioritize natural alternatives to synthetic polymer-based products when available 6
Maintain excellent oral hygiene with minimal product use—brushing twice daily with fluoride toothpaste using pea-sized amounts for children, as recommended by the CDC 5
Supervise young children during toothbrushing to minimize ingestion of oral healthcare products containing microplastics 5
Clinical Context
While microplastics in gum and oral products warrant concern, the evidence does not support avoiding all such products entirely, as the dental health benefits of proper oral hygiene outweigh theoretical microplastic risks based on current knowledge. The polymer hazard index for identified plastics in oral products ranges from low to high risk categories, with polyvinyl chloride (PVC) showing the highest concern due to elevated polymer hazard index and maximal risk level 1, 4.
The annual microplastic addition to the environment through toothpaste alone is estimated at 1.4 billion grams per year for India, indicating substantial environmental burden that may translate to human exposure 2. However, until definitive human health outcome data emerge, maintaining good oral hygiene practices remains the priority, with reasonable efforts to minimize unnecessary microplastic exposure through product selection and water filtration 5, 3.