Chewing gum is a favorite of high school kids and overworked professionals alike – but just one piece can shed thousands of potentially harmful microplastics into your saliva, one study suggests.
The research adds to growing concerns about microplastics in food.
Chewing a single gram of gum could release an average of 100 microplastics, the study found. A piece of gum typically weighs between 2 and 6 grams, and larger pieces may release up to 3,000 plastic particles. Someone chewing 160 to 180 pieces of gum a year could ingest roughly 30,000 microplastics, it found.
For their pilot study, the researchers, from the University of California, Los Angeles, tested 10 popular brands of chewing gum: five synthetic and five made with natural ingredients.
The researchers presented their findings at a March meeting of the American Chemical Society, although it is still undergoing peer review.
Some plastics are “food grade” – they contain fewer toxic ingredients, and the Food and Drug Administration allows them for use in food. Even so, studies from 2023 and earlier this year highlight potential health concerns about small plastic particles in what people eat.
Researchers are still determining the risks of ingesting microplastics. One 2024 study suggests it may increase the risk of heart attack and other cardiovascular problems among people with heart disease. Exposure to microplastics can disrupt the gut biome, lower sperm quality and testosterone, and impair learning and memory, according to studies on mice.
Intentionally added plastic
Microplastics typically form when plastic products break down in the environment into ever-smaller pieces. They eventually become so tiny that they can permeate almost anything, including our bodies.
Scientists are still studying how plastic particles have managed to become so ubiquitous in our environment and how they find their way into our food. Last year, EWG scientists released an analysis of plastics in food, estimating that the average person consumes up to 150,000 plastic particles annually – the equivalent of 12 plastic bags.
People can ingest microplastics inadvetently, for example, if a cap on bottled water sheds particles into the water, which someone then drinks. But plastic in chewing gum is different, because some manufacturers intentionally add it as an ingredient.
Many widely sold types of gum use ingredients like polyethylene – similar to the plastic used to make shopping bags – as part of their “gum base,” the chewy component of gum that provides its texture. Each company keeps the composition of their gum base a secret, so it’s difficult to tell which ingredients they use.
Some gum makers also use ingredients such as polyvinyl acetate, commonly used in glue and mascara products as a stabilizer, or styrene-butadiene rubber, similar to what’s found in tires or the heel of your shoe.
But the versions of these chemicals made for chewing gum don’t exactly match what’s found in tires. Food grade plastic is used in everything from peanut butter jars to yogurt cups. It’s manufactured to have fewer toxic additives and chemicals, but that doesn’t mean there are no concerns about it.
Reducing microplastic exposure
The UCLA researchers didn’t find much difference between the natural and synthetic gums. Chewing one gram of synthetic gum released an average of 104 microplastic particles, while one gram of natural gum released 96. They weren’t sure whether this was because of the ingredients used or some other factor, but they did tell CNN that other types of food can be contaminated with microplastics due to how they’re processed or packaged.
The study sampled only 10 brands. Other types of gum might release fewer microplastics when chewed. It’s also important to note that the researchers didn’t quantify the size of the synthetic or natural gum-derived particles, a difference that could determine whether they pass through the digestive tract or infiltrate the blood stream and other parts of the body.
There are other reasons besides microplastics to think twice before chewing gum. Many chewing gum brands use synthetic food dyes or contain additives like titanium dioxide that have been linked to health harms. Some types of gum can also contain propyl gallate, a preservative that has been linked to hormone disruption.
It’s likely impossible to completely eliminate your exposure to plastic particles. But your body can fight to filter out environmental toxic substances. So it’s still a good idea to limit your exposure to plastics, when feasible.EWG recommends the following:
- Switch to wood cutting boards. EWG’s 2024 analysis shows that plastic cutting boards are a leading source of exposure based on how someone eats. Polyethylene cutting boards alone made up 70 percent of the overall annual plastic ingestion estimate. Swapping plastic cutting boards for alternatives that don’t increase plastic exposure (such as wood cutting boards) can be a simple and fairly affordable option.
- Change bottled water drinking practices. There are many financial, seasonal and other factors that can affect whether you can lower how much you drink from plastic bottles. But no matter your situation, you can cut the amount of plastic you’re exposed to by not drinking from bottles that are heavily squeezed or left in the sun.
- Avoid use of reusable plastic containers as much as possible. To store takeout or produce, EWG recommends glass containers, whenever possible, to prevent contamination from plastic degradation. More importantly, try to use glass containers with plastic lids removed when microwaving foods to avoid speeding up breakdown contamination.
