Why we should be worried about the microplastics in chewing gum

Many people think it’s a disgusting habit but now scientists believe it’s also bad for your health

Every year, the British public munches through around four billion pieces of chewing gum. But what may be less well known is that a significant proportion of that gum comes from the exact same plastic materials that can be found in car tires and shampoo bottles.

It’s something that campaigners are looking to change. The group Kids Against Plastic is now calling for the Government to ban sales of all plastic-containing chewing gums to children. At the same time, a parliamentary motion based on a new policy paper, calling for all plastic-based chewing gums to be clearly labelled as such, has been signed by 41 MPs from across the House of Commons.

“The proposals are to make everything more transparent and put warning signs which say, ‘This contains plastic, you are consuming plastic,’ so consumers are informed,” says David Jones, a teaching fellow at the University of Portsmouth, and chief executive of Just One Ocean, one of the charities behind the paper. “The idea is to encourage [natural] alternatives to be used and potentially provide tax breaks or something like that, in order to help facilitate that.”

The urgency of this movement has been accelerated by recent science. While some reports have suggested that chewing gum’s popularity has been declining globally for a little while, as a result of increased competition from alternatives like breath mints, the industry as a whole still represents a behemoth worth more than £37bn, according to recent estimates.

But two new studies have helped raise a key question: should we really be chewing it? The University of California Los Angeles (UCLA) published a paper earlier this week proving how we are ingesting microplastics. Saliva samples were taken from volunteers who chewed through 10 leading brands of commercially available gum. The result? Up to 3,000 tiny plastic particles were detected. The scientists estimated that particularly prolific gum users, who chew 160-180 small sticks of gum each year, might be ingesting up to 30,000 microplastics.

Sounds scary? It may be even worse. Researchers at Queen’s University Belfast used even more sensitive detection technology – capable of measuring much smaller amounts of plastic – to examine the saliva of one volunteer who munched on a piece of chewing gum for an hour. They identified 250,000 microplastics, and even traces of nanoplastics – plastics so vanishingly small that they are thought to be capable of interacting with cell membranes.

“Because of their tiny size, nanoplastics pose more penetrative power, and can reach the internal organs of our body,” says Udit Pant, a researcher in the advanced micro- and nanodiagnostics lab at Queen’s University Belfast, who led the study.

A short history of chewing gum

Despite the scary statistics, humans are unlikely to stop using chewing gum any time soon, not least because its place in our culture dates back at least 10,000 years. Archaeologists have found fossil records of Stone Age teenagers in Sweden chewing on pieces of tar-like black resin from birch trees, while the ancient Greek and Mayan civilisations were also highly fond of chomping on gums made from various tree and plant resins.

But what we more commonly know today as chewing gum first began in the 1840s when an American entrepreneur called John Curtis developed a method of boiling resin on a stove to form a sticky, rubbery material, which he flavoured with sugar and cut into sticks. But as its popularity grew through the 20th century, natural resins like chicle, which comes from tree sap, began to be replaced by synthetic chemicals.

Chewing gum and its ingredients

Chewing gum is defined by its so-called “gum base” – the chewy, stretchy texture which makes it feel nice to bite into and acts as a delivery system for flavourings and sweeteners.

The precise composition of this gum base has long been a tightly kept trade secret, but academics have slowly been able to narrow down what’s actually in it, and it turns out that many of the components that give chewing gum its most appealing qualities aren’t things we would normally want to put in our mouths. Research suggests that many people are completely unaware of this – one survey of 2,000 people in Iceland found that 85 per cent had no idea that plastic was in chewing gum.

“Manufacturers get away with hiding the whole issue of plastics in chewing gum by calling it gum base,” says Jones. “But the gum base generally makes up around 30 per cent of the weight of a piece of chewing gum, and it’s made up of a number of plastics. They’re flying under the radar, where all other plastic manufacturers have to abide by certain pollution regulations, and strive towards reducing, recycling and rethinking, and they do none of that.”

According to UCLA researchers, the rough proportions for a typical gum base are as follows:

10-45% elastomers

In some cases, nearly half of the gum base comes from synthetic materials called elastomers which give chewing gum its elastic texture, and ensure it’s more likely to stick to itself rather than surfaces like your teeth. Common elastomers include oil-based synthetic rubbers like styrene-butadiene (the durable chemical used in car tyres) which provides cohesiveness, and polyethylene (used to make carrier bags and plastic bottles), which softens the gum and makes it less likely to tire out your jaw.

Plasticisers help ensure better chewability. One example is polyvinyl acetate which is better known as wood glue.

What exactly is in your packet of chewing gum?

1. Sweeteners

Xylitol and sorbitol

These are sugar alcohols, or polyols which are found naturally in various plants, but also produced commercially as artificial sweeteners in foods, such as sugar-free chewing gum, mints and other low-calorie products. One review of studies found that people with IBS reported symptoms such as flatulence, bloating and abdominal discomfort, even when consuming lower amounts than people without IBS.

Aspartame

Linked to cancer, cardiovascular disease and Type 2 diabetes, though evidence is limited and can cause headaches and blurred vision in some people.

Mannitol

A type of sugar alcohol that’s considered “tooth-friendly” and adds sweetness, a cooling taste and texture.

Acesulfame K

A sweetener that could impact insulin production, one of the factors in Type 2 diabetes and may increase gut inflammation.

2. Gum base

Humectant (glycerol)

A food additive that is added to reduce the loss of moisture.

Thickener (gum arabic)

Added to bind the ingredients and create a smooth texture.

3. Flavourings

Emulsifier (soya lecithin)

These make the gum texture smooth and pliable and stabilise other ingredients, including flavours and colourings, so they’re well mixed.

Glazing agent (carnauba wax)

Added to create the crunch on the outside of the chewing gum pellet.

Antioxidant (BHA)

Added to preserve the gum.

What could these plastics be doing to us?

The UCLA study found that the vast majority of microplastics appear to be released into our mouths within the first two minutes of chewing on a piece of gum. As Sanjay Mohanty, an associate professor at UCLA, explains, the forces exerted during chewing have such an abrasive effect on the plastic within the gum, they cause tiny pieces to flake off.

“When we chew, we break the polymers [the materials in the gum base] and create plastic particles,” says Mohanty. “The majority stay inside the gum because it’s very sticky, but some gets into our saliva.”

In recent years, numerous studies have shown that tiny pieces of plastic can get almost anywhere in our body, having been identified in bone, skeletal muscle, blood, the testicles and major organs like the heart and lungs. Microplastics have even been found in post-mortem brain tissue.

Pant says that he is concerned about the possible consequences of polyvinyl acetate plastic particles, as its precursor – a material used to produce it – vinyl acetate, has been listed by the International Agency for Research on Cancer as being possibly carcinogenic to humans.

However, as all microplastics researchers point out, as yet, no concrete links have been established between the accumulation of these plastic particles in our bodies and a particular disease. We also still know very little about exactly how much of the plastic we ingest is excreted out, and how much lingers in our bodies.

One of the main theories is that the presence of microplastics may serve as an additional stress on the body. “Microplastics may have a role in amplifying inflammation,” says Verena Pichler, an associate professor at the University of Vienna. “This is concerning because chronic inflammation is a well-established driver of various diseases, including cancer.”

Scientists are particularly concerned about the possible role of nanoplastics, due to their smaller size and ability to penetrate cells. There has been speculation that these plastics could affect sperm count and even drive DNA damage.

Should we still chew gum?

At the same time, because research into the possible health consequences of microplastics is still at a distinctly nascent stage and firm conclusions have yet to be reached, researchers are reluctant to advise people to not chew gum at all.

In the past decade some research has suggested that chewing gum could have mental health benefits for stressed-out students facing university deadlines, and that the act of repetitive chewing could reduce appetite and promote satiety, preventing overeating. Mondelez, one of the world’s largest snack companies, is now funding research into how incorporating antimicrobials into future chewing gum products might be used to improve oral health by disrupting harmful populations of bacteria in plaque on our teeth.

For Prof Avijit Banerjee, a dentistry researcher at King’s College London, while the new microplastics studies are interesting, his predominant concern for now when it comes to chewing gum is the contribution to our overall dietary sugar, rather than the possible unknown effects of plastic.

“You’re putting a sugar load into the mouth, which can potentially over time and with repetitive use increase risk of tooth decay,” says Banerjee. “And the difficulty nowadays is that people have the psychological tendency to binge more. One sugary sweet or piece of gum on its own is not going to cause any issues, but overall, it can contribute to a total sugar intake, which has health risks. But when it comes to sugar-free chewing gums, I think there’s been some studies which show that they might potentially have some health benefits.”

Previous research published in the British Dental Journal, supported by chewing gum company Wrigley, has concluded that sugar-free gum could potentially save the NHS millions in dental care by helping neutralise plaque and supporting the remineralisation of tooth enamel.

The way forward

While the results of the Queen’s University Belfast study in particular are somewhat shocking, both Jones and Mohanty point out that chewing gum is far from the biggest contributor to microplastics in our lives. Mohanty notes that we probably get far more microplastics on a daily basis from heating plastic teabags in hot water, while Jones says that the largest contributor of all is the fabrics industry.

The UCLA study also indicated that people can still end up ingesting plastic particles from naturally derived chewing gums, perhaps due to particles which have become incorporated in the gum through plastic packaging and the production process.

Still, in the wake of the recent evidence on microplastics, Jones is keen for the Government to push more chewing gum manufacturers to replace the plastic within their products with natural alternatives.

“It’s a small part of the problem in the grander scheme of things, but it’s a problem which could also quite easily be addressed,” he says. “It would be an almighty upheaval for the industry, but we could replace the plastic gum base with natural alternatives.”

For avid gum users, there’s also a simple solution we can all take. Simply chew one piece for longer, instead of popping in a new one.

“Within eight minutes of chewing a piece of gum, you release most of the microplastics that can be released,” says Mohanty. “So if you keep chewing that gum for longer, it doesn’t change much.”

David Cox     28 October 2025

source: www.telegraph.co.uk