Toothpaste has been around for a very long time with historic references as far back as 377 BC. Modern toothpastes are very different though and contain a myriad of ingredients to improve their mechanical properties, appearance, or smell in order to appeal to consumers. Should we be worried?
Two caveats are needed upfront.
First one, please note the question mark in the title. I am not saying that toothpaste is dangerous, just asking the question after some recent experiences.
Second one, although toothpaste is not food, and this blog is about food, you will at least inadvertently swallow some, and some ingredients will easily be absorbed through the lining of the mouth with a 90% efficiency.
So here we go.
The best toothpaste ever
Some years back our brand of toothpaste exclaimed it was clean and fresh. We were quite happy with that, what more could you ask for? But the marketing gurus obviously thought you needed more so changed it to extra clean and fresh. That’s fine too we thought. We don’t mind having extra clean teeth.
Never satisfied the marketing gurus wanted something more so changed to extra clean and lasting fresh. Well, come on now, didn’t the freshness last before? But there’s more, now the toothpaste exclaims it is extremely clean and lasting fresh. This must be the best toothpaste ever. And this is how they describe the effects:
- This toothpaste doesn’t just freshen your breath, it invigorates it.
- Thanks to its micro-active foam that leaves you with a pure breath sensation that last and a feeling of clean like no other.
So what is different?
Curious, for once we decided to read the small print on the tube. Upfront there are several warnings:
- “Do not swallow, be sure to spit out”
- “Not for use by children 6 years of age and under”
- “Do not brush more than three times a day”
- “If irritation occurs discontinue use”
Quite a list of warnings and as it happened one of us had an “irritation” and had to stop using it. The label claimed it could possibly be an allergy to one of the ingredients.
Checking the ingredients
So what is in this toothpaste? Quite a lot as it happens, but at least no sugar it claims upfront. That’s a relief.
First on the list of ingredients is water and not much to say about that.
Second is the sugar substitute sorbitol followed much further down the list by the artificial sweetener sodium saccharin. Of course, even if there is no sugar, a sweet taste is important for palatability. Saccharin has been shown to cause bladder cancer in rats, but through a mechanism that is not available in humans. No harmful effects are expected from those two ingredients although artificial sweeteners like saccharin might influence the gut flora. This is still to be clarified.
Hydrated silica is an odourless, tasteless, white, gelatinous substance, which is chemically inert. As a fine gel it is abrasive and helps to remove plaque. It is generally considered to be safe, although it might wear down the enamel exposing the dentin underneath.
Glycerin is a colourless, odourless, viscous liquid that is sweet-tasting and non-toxic, so no problem there.
Pentasodium triphosphate is produced on a large scale as a component of many domestic and industrial products, particularly detergents. It has very low human toxicity but in volume can have negative environmental effects by supporting algal growth.
PEG-6 (polyethylene glycol) belongs to a group of petroleum-based compounds that are widely used in cosmetics as thickeners, solvents, softeners, and moisture-carriers. In itself not considered toxic although it can inadvertently be contaminated by other toxic compounds depending on the manufacturing process. A minority of people are allergic to PEG compounds.
Alumina or aluminium oxide is primarily used as an abrasive and thickening agent, but also functions as an anti-caking agent and absorbent. It is safe to use for cosmetic purposes. However, it must be noted that aluminum is a neurotoxin.
Sodium lauryl sulfate is a surfactant responsible for the foaming action of the toothpaste but it also interferes with the functioning of taste buds by breaking up phospholipids on the tongue. As it is further down the ingredient list the amount in the toothpaste should be fairly low but it should be noted that it has been linked to skin irritation and painful canker sores, with research suggesting that the compound should not be used in people with recurring sores. Sodium lauryl sulfate could potentially be contaminated with 1,4 dioxane, a carcinogenic byproduct.
Flavour is not further specified but might be mint as it is common in toothpaste.
Xanthan gum is a common food additive. It is an effective thickening agent and stabiliser to prevent ingredients from separating. It can cause some side effects such as flatulence and bloating in high doses, but the low amount in toothpaste should not be a problem.
Cocamidopropyl betaine is a mixture of closely related organic compounds derived from coconut oil and dimethylaminopropylamine. It is used as a surfactant and foam booster. It can be an irritant particularly if impurities like amidoamine and dimethylaminopropylamine are not tightly controlled.
Sodium citrate possesses a saline, mildly tart flavour. It is commonly used for flavour or as a preservative. The chemical has been verified to be of low concern.
Titanium dioxide is often used as a pigment, brightener, and opacifier, which is an ingredient that makes a formulation more opaque. Although not relevant for toothpaste, if in powder form and inhaled it can possibly cause cancer. However, titanium dioxide in toothpaste may become dangerous when it is nanoparticle size, an issue still to be resolved.
Carrageenan is an extract from a red seaweed commonly known as Irish Moss. It is a native to the British Isles, where it’s been used in traditional cooking for hundreds of years. Some scientists claim that it can cause a range of health effects while others claim it is perfectly safe. Although the jury is still out, amounts in toothpaste is supposedly too low to cause any health effects.
Sodium fluoride is another controversial compound. It can be toxic in high doses but the low doses ingested through toothpaste and fluoridated water can in a worst case situation cause some slight discolouration of children’s teeth. There have only ever been three reported cases of fluoride toxicity associated with the ingestion of fluoride-containing toothpaste. One involved a 45 year old woman with unusual swelling and pain in her fingers. As it happened the woman admitted to the regular ingestion of large amounts of toothpaste, consuming a tube of it every two days because she “liked the taste”. When asked to switch to a non-fluoride form of toothpaste, her condition subsided.
Zinc chloride polishes the teeth and reduces oral odour by destroying or inhibiting the growth of microorganisms. We need zinc for healthy development, but in high doses it might cause nausea, vomiting, diarrhea, metallic taste, kidney and stomach damage in some people. Levels in toothpaste are generally considered as safe.
Sodium hydroxide is a good example of a compound that can cause harm in high doses but is completely harmless in a diluted form.
Limonene is a chemical found in the peels of citrus fruits and in other plants. It is used to make medicine and as a flavouring. Limonene is safe in food amounts. It also appears to be safe for most people in medicinal amounts when taken by mouth for up to one year.
CI 74160 Phthalocyanine blue BN is a bright, crystalline, synthetic blue pigment. The compound is non-biodegradable, but not toxic to fish or plants. No specific dangers have been associated with this compound.
CI 74260 Phthalocyanine green G is a synthetic green pigment available in the form of a soft powder. Classified as not expected to be potentially toxic or harmful although one or more animal studies have shown toxic effects at moderate doses.
So what to do
Well I am happily continuing to use the toothpaste but with some reflections each time. I wouldn’t mind if they removed the blue and green colourings. Sure it looks nice with blue and green stripes among the white but is it really necessary. And to the whiter than white from titanium dioxide, do we need the nanoparticles?
I am happy that they have resisted putting triclosan in their toothpaste to stop bacterial growth as the zinc chloride might to the job as efficiently. But I can only hope that they have full control of their chemistry to avoid toxic byproducts being formed.
Regulators in different countries provide some controls for toothpastes but I would be surprised if there were any extensive testing of the product on the market.
On the other hand we only use about 0.3g of toothpaste per brush so exposure to any of the chemicals in the toothpaste is minimal.
Good to know!