A review of the effects of oil pulling concluded that, indeed, the ancient practice “may have beneficial effects on oro dental hygiene,” or oral and dental health. I’ve talked before about studies investigating oil pulling and dental health, but what about oral health? That’s the subject of my video Oil Pulling for Teeth Whitening and Bad Breath Tested.
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 researchers decided to put oil pulling versus chlorhexidine to the test, but how do you test for bad breath? There are all sorts of really fancy methods, such as “gas chromatography electronic nose, diamond probes, dark field microscopy,” but they are really expensive or not very reliable. So, the researchers decided to go with the “gold standard”: Study subjects were told to just breathe into the examiner’s face.
The researchers also wanted to know what the subjects thought about their own breath, so they instructed them to lick their own wrist, sniff it after it had dried, and then give the smell a score from zero (no odor present) to five (extremely foul odor). Though the subjects themselves thought their licked wrists smelled better after two weeks of oil pulling, the researchers disagreed that their breath smelled any better. You can see the scores at 1:07 in my video.
After three weeks, however, there was a significant and comparable improvement in breath odor in both the oil pulling and chlorhexidine groups. I was excited about this study, because the researchers used an actual placebo—colored water, in this case—presumably to match the look of the chlorhexidine and also had the subjects swish for the same duration. Finally! At last, we can answer that nagging question as to whether plaque and gingivitis improves with oil pulling because of the oil, or just because swishing anything in your mouth for that long will make a difference. In fact, as you can see at 1:50 in my video, the water worked just as well. The researchers saw the same drop whether the test subjects swished with oil or swished with plain water, suggesting that the plaque is simply disrupted by the extended “rinsing action.” Yes, oil may be five to six times cheaper than chlorhexidine and safer, too, but water is cheaper and safer than both.
But can water whiten teeth? Numerous websites offer testimonials of oil pulling whitening teeth, but with no studies published in the medical literature, most doctors would just give up there. Not all doctors, though. Two dental professors in Detroit decided to put it to the test. “Teeth were selected from a stored collection of human extracted teeth”—sounds a little horror movie-ish—and then put into tubes with coconut oil, sesame oil, or sunflower oil, along with some fake saliva. The professors vigorously shook the tubes every day for two weeks. The result? No evidence to suggest that oil pulling has any effect on teeth whitening.
Another internet darling—“DIY whitening consist[ing] of a strawberry and baking soda mix,” which was evidently featured on Dr. Oz—had a similar outcome when put to the test. Over-the-counter whitening strips worked, a home whitening system in which the dentist sends you away with custom trays also worked, as did in-office tooth whitening, but the DIY strawberry and baking soda mixture failed. It was as bad as plain water, which had been used as a control. You can see the results at 3:05 in my video.
What about dental erosion? In my video Plant-Based Diets: Dental Health, I talked about how those eating more healthfully may have healthier gums, but since they tend to consume more acidic food and drink like citrus, tomatoes, and fruity teas, they may be at greater risk of eroding some of their enamel, which is why we should all rinse our mouth with water after eating or drinking anything acidic or sour. What about rinsing with oil every morning? The way our body protects against dental erosion is by forming a “pellicle”—a protective layer of mostly proteins from our saliva and some fat—over our teeth. Might oil pulling help prevent erosive damage to our tooth surfaces by, in a way, buttressing this protective layer? You don’t know until you put it to the test.
The researchers wanted to put the teeth under a microscope afterwards, but that’s hard to do when the teeth are still in people’s heads. So, they put slabs of cow’s teeth in the subjects’ mouths, 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.
As you can see at 4:43 in my video, 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, if you let those same teeth sit in your mouth for a few minutes before exposing them to acid, there’s less erosion. What happens if you then put them back into 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. Indeed, that’s exactly what the researchers saw under the microscope, as you can see yourself at 5:20 in my video. The researchers suspect the oil may actually be depleting the pellicle, “impairing its protective properties.”
For the final video of this series and the final nail in the coffin of oil pulling, see The Risks of Oil Pulling.
How can we protect our enamel? See:
Michael Greger, M.D.
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