Is CAPB in SLS-Free Toothpaste Any Better?

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

Sodium lauryl sulfate had already been “used as a foaming agent” in toothpastes for more than a half-century by the time this study was published, which showed tissue damage in most of those who had it smeared on their gums—but most of just ten people. The same with the study that showed a dramatic decrease in the number of canker sores when switching to an SLS-free toothpaste—just ten people. But, that’s all we had, until 1999, when a randomized, double-blind, crossover trial was published: SLS versus non-SLS toothpaste in not just ten people, but 47 people with recurrent canker sores; looking at the number of days of suffering, total pain, number of ulcers, how long they lasted, how big they were. And, “no significant” differences were noted. It didn’t seem to matter whether the toothpaste had sodium lauryl sulfate or not.

But, what about the study showing the 70% decrease? Well, maybe it’s because those cases were worse. And so, the type of toothpaste only matters if you have really bad canker sores. And, that’s where the science ended, until 13 years later, when Korean researchers picked up the torch.

We had studies showing SLS-free toothpaste helps; we had other studies that found no benefit, leading “to considerable controversy.” And so, they launched the biggest study to date—90 subjects, and, same number of ulcers and ulcer episodes. But, the duration they lasted for, and average pain score was significantly less when they were using the SLS-free toothpaste. So, switching to an SLS-free toothpaste may “not reduce the number of” canker sores you get, but, it may allow them to heal faster, and make them less painful.

So, yeah, sodium lauryl sulfate can create an “impression of cleanliness,…a mouthful of foam ‘just feels cleaner.'” But, there may be a downside: potentially “reduc[ing] the protective barrier of [our mouth lining],…probably due to [the] rupture of the [bonds that hold our cells together], sometimes causing “sloughing, ulcerations, and inflammation,” drying out “the protective mucous layer lining” our mouth, making us more “vulnerable to irritants.”

But, wait; how do they explain that their study found a problem, but the last study didn’t? They suggest it could be a race issue. What? Well, they explain Koreans tend to love their spicy food; and so, maybe that makes a difference. Regardless, if you get canker sores, you may want to give an SLS-free toothpaste a try to see if it makes any difference in your case.

But, non-SLS toothpaste may just have other detergents, most commonly cocamidopropyl betaine. Is that any better? Well, what these Swiss researchers did was to take nine toothpastes—Colgate, Crest, Oral-B, Sensodyne, etc., and drip them on some human gum cells taken fresh from people who had their wisdom teeth extracted, and then use “live-dead cell staining.” Basically, you stain all the cells green, and then, you add a red dye that covers up the green—but only in dead cells, because the live cells actively pump out the red dye. So then, live cells stay green, but dead cells turn red.

Let’s see if you can guess if Colgate has SLS in it. All red, all dead. What about Crest? Mostly red, mostly dead. But, guess if Sensodyne has SLS in it. All green, all alive. And indeed, it has the SLS-free detergent CAPB instead. What about Oral-B? SLS or no? Versus this one, this one, or this one? It seems pretty clear which is which.

But that’s in a petri dish. Does that translate out into actual tissue damage in people? A double-blind crossover study: SLS-containing toothpastes versus CAPB-containing toothpastes. Forty-two desquamative reactions, meaning tissue-peeling reactions, after four days of four minutes a day of the SLS toothpaste on their gums, compared to just three with the alternate detergent. And, no such reactions at all using the exact same toothpaste, but with just no detergents at all; neither SLS nor CAPB. How does this translate out into canker sore frequency?

How about a randomized, double-blind, crossover study “to investigate the effect of toothpastes containing” SLS versus CAPB, versus no detergent at all? They found “significantly higher frequency of [canker sores]” when patients brushed with an SLS-containing toothpaste than with a non-SLS toothpaste.  So, they suggest that “SLS-free toothpastes…be recommended for patients with recurrent [canker sores].” But, they found more than just that.

Yes, SLS was the worst, but the non-foaming toothpaste—the detergent-free toothpaste—beat them both out. The non-foaming toothpaste “caused significantly fewer…ulcers” than the non-SLS alternative detergent, CAPB, which in turn “caused significantly fewer…ulcers” than the SLS toothpaste. So, the vast majority of recurring canker sore patients would benefit from switching from a regular toothpaste to a non-foaming toothpaste, but most would benefit just staying away from the SLS, regardless.

But, if your toothpaste doesn’t have sodium lauryl sulfate, will it work as well? I’m not just talking about “the impression of cleanliness,” but actual like plaque and gingivitis. Yeah, SLS may kill our cells, but it also kills bacteria cells; so, might SLS-free toothpaste not work as well? We didn’t know, until now.

And, it turns out the SLS-free toothpaste worked just as well, with regard to reducing gingivitis and plaque, and so can be “recommended for [those with] recurrent [canker sores],” since sodium lauryl sulfate may make things worse by disintegrating the protective mucous layer, and eventually penetrating into the deeper layers of the lining of our mouth, where “living tissue [function] may be compromised.”

However, folks did miss the foaminess. Though there is one additional benefit to choosing SLS-free toothpaste: SLS also penetrates into our tongue, and interferes with the inner mechanisms of our taste cells. Sodium lauryl sulfate is what’s responsible for the “orange juice effect,” that weird taste you get from citrus right after you brush. SLS is evidently what’s mucking with your taste cells.

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Image credit: Kristina DeMuth. Image has been modified.

Motion graphics by Avocado Video. 

• aphthous ulcers
• cancer
• canker sores
• dental health
• inflammation
• oral cancer
• sodium lauryl sulfate
• toothpaste