Flashback Friday: Oil Pulling Benefits for Plaque, Gingivitis, Teeth Whitening, and Bad Breath Tested

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.

What are the potential risks and benefits of the “ancient practice” of oil pulling, in which oil is swished or pulled between the teeth for like 15 minutes, and then spit out? There are wild, unsubstantiated claims online, and even in the medical literature. I can believe it’s “good exercise” for your tongue and cheek muscles, but “heal[ing]…all organs simultaneously”? That statement seems a bit of a tongue-in-cheek exercise right there!

Respondents in the British Medical Journal expressed surprise reading that swishing some oil around in the mouth could “effectively treat [diseases like] meningitis [and heart/kidney/hormone] disorders.” Oh, did I mention “cancer, AIDS, etc.”?

Look, it may help in some way, but for things to enter into evidence-based medicine, we actually need a little something called evidence, “without being distracted by illusory effects ascribed…by their advocates,” especially when another set of respondents shared their experience of a case of “severe inflammatory” gingivitis that worsened after oil pulling. She stopped, and it got better. They were thinking maybe some of the oil got like stuck under her gums. Regardless, maybe people should hold off until we actually have some evidence.

Thankfully, there’s a Centre for Evidence-Based Medicine at Oxford that recently compiled all the controlled trials. Why is it so important there’s a control group? Because maybe the reported declines in gingivitis and plaques with oil pulling are just because, in the study, they had dentists looking over their shoulders, with constant check-ups. So, maybe the study subjects just upped their brushing-and-flossing game.

This is the kind of study we need. No changes before and after in the control group, but a drop in plaque and gingivitis scores in the oil-pulling group. That’s more like it. Okay, so there does seem to be an effect.

But, what do those numbers mean? When you test a new drug, it’s not enough to show it works better than nothing—better than a sugar pill. What you ideally want to know is does the new drug work better than the current best drug out there, for the same condition? Otherwise, what’s the point of a new therapy? That’s why drug companies are often forced to use so-called active controls; comparing their drug not just compared to nothing, a placebo, but head-to-head against the leading drug. Here, oil pulling is compared to doing nothing. How about oil pulling compared to chlorhexidine, an antiseptic chemical used in medicated mouthwash, which is considered to be “a gold standard” in the fight against plaque, cavities, and gingivitis?

So, here we go. Ladies and gentlemen—in one corner, we have oil pulling. In the other, chlorhexidine, measuring their ability to lower the number of cavity-producing bacteria on people’s teeth. And…chlorhexidine worked faster, a significant drop within just 24 hours, whereas, it took a week for the oil pulling to really start working. But, by two weeks, the oil pulling may end up just as efficacious as the gold standard. In fact, they appeared to work so similarly that skeptical me is critically thinking, “Wait a second, maybe it’s just the physical act of swishing that disrupts the plaque?” It would have been cool if they included a third group that just swished with water. A,nd they did! And, swishing with water had…no effect.

Now, it wasn’t exactly fair; they had the oil-pulling group swishing for 10 minutes, whereas the other two groups only swished for one. So, for all we know, swishing with water for 10 minutes might be as good as the oil.

And, one could look at this and argue that chlorhexidine actually worked 10 times better, since it got the same effect swishing for one-tenth the time. But, chlorhexidine has side-effects—potentially serious side-effects—like painful desquamation, meaning peeling of the mucous membranes in your mouth, as well as discoloration of the teeth or tongue.

So, “oil…has certain benefits over commercially available mouthrinses.” It’s “non-chemical, non-alcoholic, low cost, and non-staining, yet the effectiveness…[is] unclear.” But wait, oil pulling has been shown to significantly drop the number of cavity-causing bacteria on the teeth.

Yeah, but does that translate out into fewer actual cavities? That’s what we really care about, but it hasn’t been studied. They did pair up oil pulling versus chlorhexidine against plaque and gingivitis, and did find they were both able to help to a similar degree. And, plaque-induced gingivitis is a reasonable predictor of future dental health, thereby explaining the Oxford Center’s conclusion that “oil pulling may [indeed] have beneficial effects on [oral and] dental health.”

A review of the effects of oil pulling concluded that the ancient practice “may [indeed] have beneficial effects on [oral and] dental health.” I have talked about the benefits for dental health, but oral health too?

Oil pulling was also tested against “oral malodor,” also known as halitosis, or, simply, bad breath. It’s believed a quarter of the world’s population suffers from it. So, they decided to put oil pulling versus chlorhexidine to the test.

How do you test for bad breath, though? There’s all sorts of really fancy methods—”gas chromatography electronic nose[s], diamond probes, dark field microscopy,” but these are really “expensive” or “not very reliable.” So, they decided to go with the “gold standard.” Study subjects were just told to breathe in the researcher’s face.

And then, they wanted to know what the study subjects thought about their own breath. So, they asked them to lick their own wrist and sniff it, then give it a score from zero to extremely foul. And though the subjects themselves thought their licked wrists smelled better after two weeks of oil puling, the researchers disagreed that their breath smelled any better.

But, after three weeks, there was a significant and comparable improvement in breath odor in the oil pulling and chlorhexidine groups. I was excited about this study, because they used an actual placebo—colored water—to presumably match the look of chlorhexidine, and swishing for the same duration. Aha! So, we can finally answer that nagging question about whether oil pulling cuts down on plaque and gingivitis because of the oil, or just because you’re swishing anything in your mouth that long. And, the water worked just as well—the same drop swishing with oil, or just swishing with water, suggesting that the plaque is just disrupted by the extended rinsing action. Yes, oil may be five or six times cheaper than chlorhexidine, and safer, but cheaper and safer than just plain water?

Yeah, but can water whiten teeth? “Numerous websites” offer testimonials of oil pulling whitening teeth, but there were no studies published in the medical literature. And so, most doctors would just give up there. But these two dental professors in Detroit decided to put it to the test. “Teeth were selected from [their} stored collection of human extracted teeth [sounds a little horror movie-ish].” Then, they put them in tubes with coconut oil, sesame oil, and sunflower oil, along with some fake saliva, and vigorously shake them every day for two weeks and found…”no evidence to suggest” that oil pulling has any effect on teeth whitening.

That’s like when another internet darling was put to the test—strawberries and baking soda, which was evidently featured on Dr. Oz. Over-the-counter whitening strips worked; a home whitening system works, where the dentist sends you home with custom trays; and in-office tooth whitening works. But the DIY strawberry-baking soda mixture failed—as bad as just plain water, used as a control.

What about dental erosion? In my video on plant-based diets and dental health, I talked about how those eating healthier may have healthier gums. But, because they tend to eat more acidic foods, like citrus, and tomatoes, and fruity teas, they may be at more risk for eroding off some of their enamel, which is why we should rinse our mouth with water after eating or drinking anything acidic (anything sour).

But what about rinsing with oil every morning? The way our body protects our teeth from erosion is by forming a “pellicle” over our teeth—a protective layer, of mostly proteins from our saliva, but some fat, too. So, hey, might oil pulling help “prevent erosive damage” to our tooth surfaces by kind of buttressing this protective layer? You don’t know, until you put it to the test.

Now, they wanted to put the teeth under a microscope afterwards, and that’s hard to do when they’re still in people’s heads. So, they put “slabs” of cattle teeth in their mouth, let them sit there until that protective layer developed, and then, oil pulled around the teeth—or not, in the control group, and then took them out, and exposed them to acid.

If you expose the teeth to acid without putting them in your mouth, within two minutes—120 seconds—significant demineralization takes place. Calcium is dissolved out of the teeth by the acid. But, just let those same teeth roll around in your mouth for a few minutes, and then expose them to acid, there’s less erosion.

Okay, but then, what happens if you put them in your mouth and do some oil pulling? Is there even less erosion? No, there’s more. It’s as if the oil pulling undermined the protective layer. And, that’s exactly what they saw under the microscope. Here’s what that protective layer looks like before the oil pulling, and then after. They suspect the oil may actually be depleting the protective layer of some of its protection.

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