The impetus for this post is from an email I received from an employee asking about oil pulling. Specifically, he emailed me some info about how oil pulling is trending everywhere, in this case the FASHIONlush Blog. Interestingly enough a couple of the girls who work here were also discussing it.
Oil pulling (aka oil swishing) is an alternative medicine practice that originated from Ayurvedic medicine. It is often used in areas where mouthwash is not an option or it is a cheaper alternative.1 Although of late it has become a trendy thing to do for a plethora of purported benefits which I will give an evidence based review of. The very term alternative medicine invokes strong feelings on both sides that tends to devolve into a tribal Eastern vs. Western medicine argument, my intent here is to judge it purely based on the evidence and avoid such arguments.
In summary, first thing in the morning, on an empty stomach, take a tablespoon of a vegetable oil such as sesame or olive oil, alternatively some use coconut oil (many use an MCT rich coconut oil as it is a liquid at room temperature) and swish it in your mouth for 20 minutes. Optionally upon completion you can rinse your mouth with salt water.1
A simple Google search yields testimonials and other personal experience anecdotes such as those listed above. Most of these paint the picture of an oral panacea. For instance one of the comments in the FASHIONlush Blog claimed the benefits are not limited to oral health, "helps my knees, back, neck... I don’t know that my teeth are any whiter but it has also almost taken away a dark spot on my neck."
A Pubmed search yields a couple randomized controlled trials (RCTs) (one pilot study as well). For the sake of brevity, I will summarize the available evidence as succinctly as possible. The first study I reviewed had an inclusion criteria that required individuals to have plaque induced gingivitis. Individuals who had used antibiotics in the past 3-4 weeks or had a history of dental treatment/use of mouthwash were excluded from the study, leaving a total 20 subjects (10 in each group). Both the mouthwash and oil pulling groups had a significant reduction in the plaque index score. One note I would add is both groups were allowed to brush once daily which may have been at least partially responsible for the bacterial reduction (assuming they were not regularly brushing before, it was not indicated).3 An additional RCT with a similar design aimed to measure the number of Streptococcus mutans (a significant contributor to tooth decay) in plaque and saliva. The chlorohexidine (mouthwash) group showed a greater statistically significant reduction of S. mutans count in plaque and saliva than the oil pulling group.4 Both of these studies were limited in terms of duration and sample size otherwise they were relatively well designed.
Asokan S., et al explain this one best:4
"The exact mechanism of the action of oil pulling therapy is not clear. It was claimed that the swishing activates the enzymes and draws the toxins out of the blood. The bottom line is that oil pulling actually cannot pull toxins out of the blood as claimed, because the oral mucosa does not act as a semi-permeable membrane to allow toxins to pass through."
But OMG it’s getting toxins out of my bod… In all seriousness the possible benefits are thought to be due to the viscosity of the oil probably inhibiting bacterial adhesion and plaque co-aggregation. One other possible mechanism speculated about is the saponification (soap-making) process that happens as a result of the alkali hydrolysis of fat.
I am far from one to fear monger, however I have to introduce the possibility of danger given the lack of research on this method. I was able to get my hands on the full text of a letter that came up in Pubmed. Specifically, some physicians were puzzled by a 56-year-old female patient who they admitted four times in six months with pneumonia. Each time she improved from treatment with broad spectrum antibiotics, however upon review of her chest CT they found the pattern was consistent with lipoid pneumonia (a form of pneumonia that develops when lipids (fat) enters the bronchial tree). Initially after performing multiple tests, the doctors were perplexed as the patient denied any specific ingestion of lipids, however upon the patients fourth admission she revealed that she had been oil pulling (and pulling the chain of her doctors by not telling them when they asked the first God knows how many times. Side note, if you are going to participate in quackery at least let your doctors know when they are trying to treat you for something serious). Each time she was discharged, she would oil pull more rigorously trying to remove the toxins from her mouth. Using Occam's razor, the physicians concluded that although one is not supposed to swallow the oil, it is likely she aspirated some of the microbe rich oil causing the aforementioned lipoid pneumonia. Upon taking the advice of her physicians and discontinuing the practice of oil pulling she has not had pneumonia since her last discharge (2 years at the time of publication).
The question you should be left with at this point about oil pulling is, compared to what? As outlined above, based on the one study at best it may be as effective as mouthwash and according to the other is inferior; this along with it takes much longer and brings a possible risk detailed above leads me to my conclusion. Namely in lieu of longer term studies, with larger sample sizes, and the current body of evidence I don't think it is worth spending twenty minutes of your morning swishing oil in your mouth, when one could simply use mouthwash for a fraction of the time and/or simply rely on brushing, flossing, and regular cleaning at the dentist. Also the position stand of the Academy of Nutrition and Dietetics stress the importance of a nutrient dense diet for maintaining /improving oral health as well.7 So you can believe the wild claims or keep your mouth minty fresh. If you would like to have a laugh and learn about this in video form check out my vid on the topic: