Recommendation: For healthy teeth and gums, form the habit of daily brushing, flossing and at least annual visits to the dentist. Then, if the thought of swishing a tablespoon of coconut, sesame, or sunflower oil around your mouth for 10-15 minutes is appealing, go for it! Some research suggesting oil pulling’s ability to support oral health does exist, though is certainly insufficient to form any reliable medical conclusions. Only some oils are shown effective, and there’s no set method, though the most common I found was doing it just before brushing (after you spit it out it will leave white, sudsy residue). Promising early clinical results have researchers calling for larger, more robust studies. With these new studies, they expect to find support for preliminary evidence that it treats or prevents gingivitis, plaque formation, and cavities. Furthermore, the risk of harm is virtually zero, considering this popular Indian practice is at least 1800 years old.
Side-note for mouthwash users
For reasons explained at the end of this post, if you’re serious about oral health–and want to make informed decisions–you should think twice before using mouthwash daily. I’m not recommending replacing your mouthwashing routine with oil pulling, and I don’t mean to pour your mouthwash down the drain tonight. However, I am speaking to those who care about the science of this stuff. Before you make a daily habit of using any chemicals–oil or mouthwash–it’s a good idea to learn how they work and for whom they’re effective. Makers of mouthwash and the American Dental Association don’t recommend using mouthwash daily unless you need to, so ask your dentist if this is the case. Regarding oil pulling, however, there are no concerns with daily use that I found. Also, while you won’t get the fresh breath like you do from mouthwash, the potential anti-inflammatory benefits and antioxidants in natural oils (e.g. sesame, coconut) don’t exist in synthetic mouthwash, and may provide similar and added oral health benefits. Also, even if mouthwashes are better at killing disease-causing bacteria, they are also being shown to kill potentially beneficial bacteria, too. Again, ask your dentist for evidence-based guidance, as daily use of mouthwash is not recommended for everyone.
The history & health claims of oil pulling
Oil pulling was described in an ancient Indian text called the Charaka Samhita, written sometime before 200 CE.1 The text includes “oil gargling” with the group of ancient, holistic Indian health practices making up the system called “Ayurveda”. According to the chapter 5 of the Charaka Samhita:
“Oil gargling is good for strengthening the jaws, the voice and facial increase. It is good for the sensation of taste and (for getting) the best taste coming from food. (With such gargling) one does not get dryness of throat or cracked lips. The teeth do not decay and they become deeply rooted. As well, there are no tooth-aches nor uprightness of the teeth from eating sour or even hard foods.”2
Since using a stick as a toothbrush is described in the Ayurveda text mentioned above, I assume and hope nobody is considering quitting tooth brushing in favor of only swishing/gargling oil. The point here is to examine the claim that oil pulling is effective for oral health, not to determine which single practice is most effective.
Key terms: Gingivitis, cavities, and plaque
From what I’ve found, research on oil pulling is aimed at finding it’s effect on three things: gingivitis, cavities, and plaque buildup. Gingivitis is the inflammation of gum tissue, and is caused by irritation due to plaque buildup. Plaque is a sticky film made up mostly of bacteria, and it builds up if we don’t remove it by brushing and/or flossing daily.3 If left unremoved over the course of a few days, it can become hardened and no longer removable by brushing and flossing. This hardened film is called dental calculus or “tartar” and encourages further plaque formation. When bacteria in plaque produce acids, and these acids dissolve a protective element of the tooth. This leaves a small space for bacteria to enter, known as a cavity. Cavities, a.k.a. “dental carries” are lesions or cracks in the surface of teeth which appear due to demineralization of teeth, specifically when it outpaces remineralization (which is facilitated by saliva). Demineralization is when teeth lose minerals (calcium and phosphate ions). Throughout the day, calcium and phosphate exit and enter teeth in a normal and healthy cycle of demineralization and remineralization. Certain diet, medication, and disease factors determine if remineralization overcomes the loss of minerals, and thus whether cavities form or not. While these conditions are all related, differences among them call for specific research to be done.
Preliminary research is promising, but inconclusive
A randomized, controlled, triple-blind study was planned to evaluate the ability of sesame oil pulling therapy to reduce the amount of Streptococcus mutans, a bacterial strain involved in plaque formation, and subsequent cavities. They found significant reductions in the bacteria–in plaque after 1 week, after 2 weeks in saliva.4
The following year, the same team published more controlled research on sesame oil’s ability to reduce plaque-induced gingivitis.5 20 subjects had gingivitis and were in their late-teens, hadn’t had antibiotics recently and were not regular mouthwash users. Their results:
“There was a significant reduction in the plaque index and modified gingival index scores after oil pulling therapy. Hence, in this study, oil pulling therapy was very effective against plaque-induced gingivitis both in the clinical and microbiological assessment.”
Regarding how this is possible they acknowledge the mechanism is unknown, while debunking the myth that it “pulls 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. The viscosity of the oil probably inhibits bacterial adhesion and plaque co-aggregation. The other possible mechanism might be the saponification or the ‘soap-making’ process that occurs as a result of the alkali hydrolysis of fat.” (Breaking up fat particles)
One caveat about these studies is that they didn’t clearly explain the method of oil pulling used for either study. They referenced the recommended technique of doing it first thing in the morning for 10-15 minutes, prior to brushing, on an empty stomach. However, they didn’t explicitly state this was the method used in the study.
Other studies have reviewed published research and have proposals for how oils could benefit oral health.6 Theories predict oil’s ability to increase the defense of enamel against acidic deterioration, to prevent bacterial “adherence” and colonization on teeth and gums, and possible anti-inflammatory benefits of certain molecules in natural oils. While inconclusive, we have promising research from a few studies.
Conversely, research has shown rinsing with safflower oil to be ineffective at preventing calcium/phosphate loss in teeth put in an acidic environment, short-term (0-2 minutes). This is significant, since rinsing with the oil did add lipids onto the protective “pellicle” layer, but not into the pellicle structure, itself.7 They consider that perhaps other oils which aren’t as high in triglycerides may be more effective at protecting the pellicle from acidic environments. Further research showed 10-minute rinses with linseed, safflower, and olive oil were all ineffective at preventing bacterial adhesion to teeth over an 8 hour period. The chlorhexidine mouthwash control reduced bacterial presence 85%, as expected.8
Another study tested the microbial activity of various oils against one yeast and two bacterial species common to everyone, with or without cavities. The yeast they used, “Candida albicans”, is one of the 22 species (out of over 100 Candida species) to show pathogenic ability in humans, especially when it makes up more than 40% of the fungal population in the mouth.9 According to this study, this yeast is thought to contribute to cavities (Maijala et al., 2007) based on it’s ability to do the following three things:
– to colonize hard tooth surfaces and invade the dentinal tubules (Sen et al., 1997)
– produce a large amount of acids provoking demineralization of the dental enamel (Samarayake et al., 1986)
– to dissolve hydroxyapatite (which happens in the presence of acids) (Nikawa et al. 2003)
The two bacterial strains were Streptococcus mutans and Lactobacillus casei. The results were interesting, and encourage further research to say the least. Coconut oil exhibited antimicrobial activity against Streptococcus mutans and Candida albicans. However, Sesame oil only had antibacterial activity against S. mutans whereas sunflower oil only had antifungal activity against C. albicans. Importantly, corn oil, rice bran oil, palm oil, and soybean oil had no effect on any of the three pathogens.10 Finally, L. casei was found to be resistant to all tested oils, though we have good reason to believe it isn’t a major cause of cavities, like S. mutans. Rather it can populate a cavity and thrive there once one is formed.11
I was surprised to find L. casei among the list of “bad” bacteria, as it’s commonly included in probiotic food and drink products for it’s presumed health benefits. It just goes to show that we have a lot more to learn about the role specific bacteria play in specific health processes.
Overall, we have to study these oils and diseases more thoroughly before making reliable changes to medical practice. For example, is there a certain triglyceride in coconut oil, like lauric acid, which is the sole reason it’s antibacterial? Also, how does the method of extracting oil from these plants affect it’s ability to prevent disease, considering oils oxidize in light, heat, and air? We simply don’t have enough figured out to conclude any specific benefits.
A final note on mouthwash
While brushing your teeth is a confirmed recommendation and oil pulling is still being evaluated, mouthwash is also a reasonable target of closer consideration. The American Dental Association notes that not all mouthwashes are created equal, based on active ingredients and “strength”. They, and mouthwash manufacturers, recommend speaking with your dentist before using mouthwash regularly.12 Concerns related to oral health arise due to their acidity, chemical composition, and frequency of use.13 Perhaps most important for those considering oil pulling is their effectiveness in killing bacteria–even the good kinds. Ongoing research is showing that common antibacterial rinses may even cause cardiovascular harm since they kill oral bacteria involved in blood pressure regulation. This has to do with nitric oxide, which is helpful for regulating blood pressure. We get nitrates from veggies and fruits, and certain bacteria in the mouth help with the conversion of those nitrates to nitrites. This conversion leads to increased nitric oxide. Researchers studying the effects of bacteria in this process found that “CPC” mouthwash (Crest PRO Health, Scope, Cepacol) partially inhibited this conversion, and chlorhexidine-containing (prescription) washes (Peridex) almost completely eliminated all conversion of nitrates to nitrites.14 The chemistry of how these mouthwashes work by breaking the bacterial cell wall is well understood. Since we understand this mechanism and we are starting to understand that not all oral bacteria are bad, it’s reasonable to proceed with new caution. This new data on their ability to effect blood pressure, at least, gives plenty reason for me to pause on my nightly rinse until I learn more about it.
I’m considering devoting a series of posts to oral health. Let me know what you think about oil pulling, and if you’d like to hear more about keeping your mouth and teeth healthy!