Why activated charcoal products for your teeth could do more harm than good

What is black and white and being read all over? Advertising for activated charcoal. 

While photos of charcoal-stained smiles are taking social media by storm, dental professionals are warning that the products could be hurting more than they are helping.

"There's been no research done on [how these products could affect] oral health at all," said registered dental hygienist Helen Symons, who is also a program instructor at Fanshawe College in London, Ont. 

That's why she says she wouldn't recommend people use these products. 

The black powder and pastes recommend brushing for several minutes, usually once or twice a day, over an extended period of time (weeks or months depending on the product). Promises range from a whiter, brighter smile, to a cleaner, healthier mouth.

Symons's main concern rests with the abrasive nature of the product and what it could do to your teeth and gums over time. Because so few products have been tested or properly studied, too much is unknown, she says. 

"It might remove surface stains by abrasion, but how abrasive is it?"

According to the Canadian Dental Association, activated charcoal "is abrasive and will remove surface stains from teeth, thereby allowing the natural colour of the tooth to shine through." 

But it adds that "it cannot change the actual colour of a tooth, as bleaching products that contain strong oxidizers such as peroxide do."  

"Since charcoal does not have any demonstrated health benefits, the use of oral products containing charcoal, whether short or long term, is not recommended," the CDA further said.

The American Dental Association agrees, warning "there is no evidence that shows dental products with charcoal are safe or effective for your teeth." 

The ADA points to the findings of John Brooks, a clinical professor at the University of Maryland's School of Dentistry, who published a review in the September 2017 Journal of the American Dental Association.

Like most people, Brooks admitted he too was quite taken by the claims surrounding the charcoal teeth whitening trend. "Something new always gets one's attention."

So Brooks turned to PubMed and other online academic search engines to see what science he could find to back up the many claims being made by these products. When the internet came up short, he decided to take a deep dive into the subject himself. 

"Many of the charcoal toothpaste vendors have engaged in rather blatant hyperbole to describe their products (almost all without offering scientific evidence)," he said.

Questions about chronic usage

After reviewing 50 products and a limited number of available scientific studies, he found none of the advertised products had supporting scientific evidence of their claims of detoxification, remineralization, whitening or antibacterial properties.

In fact, one unscientific study published by the University of Malaya in Malaysia actually showed teeth getting yellower, not whiter. That's likely because the charcoal was so abrasive, it removed the top, protective layer of the tooth, enamel, and revealed the dentin underneath, which is yellowish in hue, Brooks said. 

"This is just one more reason to be very cautious about using these products."

Another chief concern for Brooks is "whether the inclusion of charcoal could promote any harmful effects to the oral mucosa," the mucus membrane that lines the inside of the mouth and is quite porous. 

Charcoal has been recognized by the U.S. Food and Drug Administration (FDA) as a carcinogen, Brooks points out, which he says is of concern for "those who would use these products on a chronic basis."

Many of the products do suggest frequent use.  

Activated charcoal — a form of carbon that has been processed to increase its absorption — can be swallowed safely; medical professionals use the charcoal to treat poisonings and control intestinal gas.

But Brooks argues that level of exposure is not chronic, meaning it doesn't continue over time. The opposite is true for charcoal toothpastes and powders, which encourage daily use.

Activated charcoal has been prevalent in a number of beauty and food trends, which the BBC called, "likely at best to be aesthetic (making for an eye-catching Instagram post) to enhance its marketing value." To date, there is no scientific evidence suggesting that ingesting activated charcoal on a regular basis is beneficial to overall health. 

Another ingredient Brooks cautions about is something called bentonite clay, which he says is derived from a mineral and is typically used in skincare products. He found the substance in 19 of the 50 products he looked at in his study.

The concern there, he said, is that "some forms of bentonite clay contain crystalline silica, another recognized carcinogen by the U.S. FDA."

'No therapeutic benefit'

As for the claims that products containing activated charcoal can lead to a healthier smile? 

The CDA warns that isn't the case — especially when many of the products don't contain fluoride, a mineral that prevents and can reverse tooth decay.

"[Since] activated charcoal [is] able to bind with a wide range of products, its presence in a toothpaste can reduce the availability of its therapeutic components and interfere with its ability to deliver its intended oral health benefits," the CDA said in a statement. "[Products without fluoride] offer no therapeutic benefit and their usefulness for dental health is therefore questionable."

Marketplace reached out to three popular companies that sell charcoal-based oral care products.

Hello Charcoal said its toothpaste is "formulated to fall below the maximum abrasiveness threshold recommended by the [American Dental Association]," and said its products are "safe on enamel for everyday use." The company also said its product whitens teeth naturally by removing surface stains. 

The two others, Carbon Coco and Active Wow, did not respond.

If you are keen to whiten your smile, Symons suggests consumers should instead turn to a dental professional or use tested products.

"Look for the CDA seal of approval [and] other tested products that are accepted for use, such as whitening stripes, that you can purchase yourself or at your dentist's office," said Symons.

And Brooks's final summation after his review? 

"We categorically did not endorse the use of any of these products. We stated that consumers should use these products with caution."