Science-based Recipe for Green Tea And White Tea Mouthwash

If you have been struggling with cavities, it’s because of the combination of in short your genetics, your mouth hygiene, and your diet. What causes cavities is not directly sugar but the cavity forming bacteria S. mutans, that feeds on the sugar, acidifies your mouth thus demineralizing the teeth (dissolving them). They also form the unaesthetic and gum-harming plaque, and create glues to stick to the teeth. When you understand how cavities are formed, you understand why mouthwash exists, and why it is extremely important in the fight against cavities. Virtually regardless of diet and genetics, adding mouth hygiene by using an effective mouthwash can bring the vast army of S. mutans to a near eradication and prevent further plaque and cavities. But which mouthwash? Well two things: I hate the taste of conventional mouthwash, I don’t fancy putting in my mouth broad antiseptics, and I’m always happier when I don’t rely on “cosmetic” products, so this white tea/green tea mouthwash really got my attention. But does it really work?

Dr. Michael Greger’s website has a wonderful video called “What’s the Best Mouthwash“. In this video, he compiled scientific evidence to compare the efficacy and safety of different mouthwash solutions, commercial or homemade.
The wining solutions used green tea, and immediately it raises the usual questions: How to make it? How to use it? Are there risks (like staining teeth)? Can I use white tea instead? None these questions were addressed, making such interesting information poorly actionable. So I decided to look into the literature cited and beyond, to get some answers and hopefully convert the scientific talk into something people can easily make at home, whether health-conscious, frugal, or in places of the world with limited resources.

For those in a hurry who already decided they would go for it:

Recipe and instructions for a 0.5%green tea mouthwash :
Put 5 grams of green tea (or white tea) in 1 liter of room-temperature water, let sit 1 hour and strain. Rinse with 15mL for 30 seconds and spit. Do this after brushing your teeth or before/after a meal. WARNING: Because of the natural variation in the content of active ingredients found in tea leaves, refer to section 6) to know how to test your batch and make sure it will actually work.
Cost: ~5cts for a 500mL bottle = 2 week supply. You can’t beat that!
Based on 250g of loose green tea at about US$5 in a Chinese shop, and assuming your tea is as potent as in the study.

1) Let’s re-cap
Different studies used green tea extract, one showing how green tea helps keep a high oral pH, lowers (cavity causing) S. mutans population and reduces oral bleeding.[1] Another study showed how green tea dramatically reduces plaque accumulation, improves gingival index, and improves salivary pH. In the former study, oral pH remained above 6 (mildly acidic)  without green tea, but plummeted below 5 without (relatively very acidic). In the latter study, mean plaque score goes from 1.45 to a ridiculously low 0.11, indicating a 94% reduction in plaque. You can read more here about plaque assessments, it’s interesting.

2) Figuring out a recipe and instructions

The first study was done one a single-shot basis (not over a long period of time) and people swished 10 ml, of a 2% green tea solution that people swished for 5 minutes [1]. The sucrose solution (in your case: the meal) was taken 20 minutes after the end of swishing. Unfortunately, they mention nothing about how that “2% solution” is prepared.

The second study was done over 3 weeks. They used a 0.5% green tea solution. “The subjects were instructed to brush twice daily” and “15 ml of mouth  was rinsed for 30 s after each brushing” [2]. Unfortunately, how they prepared their green tea solution is confusing and imprecise.
When I looked into the recipe they used, I was disappointed to find a rather complicated way of explaining something simple, and they had used an recipe: “Tea was extracted by combining 3 1/2 oz. (about 7 tablespoon) of green tea with 4 cups of still (not sparkling) mineral water. The tea was steeped at room temperature for 1 h and then poured in to the lidded container, straining the tea with sieve as it is poured followed by refrigeration. The loose tea is discarded. The 500 ml concentrated tea is mixed with 1000 ml of distilled water to get 0.5% solution of tea mouthwash”.
It doesn’t say of the water was boiled or not, so by default we’re going to assume it was not, and that it doesn’t matter whether is blended or not. There are chances all these factors make some difference in the extract content.

Nothing says where that “0.5%” figure came from, and everything about their recipe is misleading. Is it fluid ounces (volume) or weight ounces? Is the water boiled or not? 4 cups doesn’t give 500mL so why did they say “The 500mL concentrated tea” instead of just “500 mL of the concentrated”, did they use the official cup measurement or not? Ah…those moments when you wish the metric system was more popular than the Kardashians.
Anyway, I solved this ambiguity though another study about green tea [3] not mentioned in the video. That study says “As in previous studies (9), the concentration used during brewing was 2 g of tea leaves per 100 ml of hot water (2%, wt/vol)”. The percentage is in weight per volume. Problem solved.

3) Should you add amla or indian gooseberry?
You can, but the study on amla [5] used a solvent extract of amla, not a water extract. So it’s fair to wonder what is the active ingredient? is it water extractable? if so would it work? and if it interacts with green or white tea. More research reading needed there.

4) “Green teath” and the white tea alternative
Some people asked in the comments of the video if it’s possible to use white tea instead to prevent stains. White tea is the young leaf of green tea basically. First of all, do the stains happen if one swishes with cold tea or could it be the hot tea? Is it in people who drink sweetened green tea, or  green tea alone? The concern for stains can only be in our heads until we get evidence that green tea swishing – not drinking – stains the teeth. There are two ways to answer the question about white tea: 1) Understand why green tea works and see if white tea has a similar same composition in that regard 2) Confirm that white tea works, for instance by doing something as simple as a pH test using paper pH testers at home, like they did in [1]. I looked into the literature to get a feel of what is responsible for effect of green tea for oral health. That was done very fast and needs more in-depth work. This being said, it seems that it’s the catechins and especially EGCG that are at play. Does white tea have that? Yes, but it’s also a bit different : “White and green teas contain similar levels of EGCG but differ in the relative amounts of other polyphenols and caffeine” [3]. This suggests white tea extract is likely to work as a mouthwash too, with the same recipe. If it doesn’t work as well that might be because of the difference composition, or just because of the greater general variation in the content of active ingredients between batches…

5) The problem of variations and how to hack it
You’re not using the same batch as in the study so the same expression “green tea” in practice can be a very different product each time.
We can be very obsessed about precise numbers in an effort to practice good science. All that precision becomes irrelevant when you start taking into account variations. In nature, the content of any compound in living things varies tremendously. That’s how selenium in a single Brazil nut can go from almost nothing to 20 times the RDI (Recommended Daily Intake). In my past work on growing methods for crops (where health begins) I came across a study showing a 10-fold difference in vitamins and minerals depending only on growing practices. Then the studies like that on Brazil nuts confirm that the composition of the soil have a profound impact on the composition and nutrient density of foods. Then you have freshness, storage, processing , distributors mixing batches from different locations, cooking/extraction technique. All this put together results in a very wide range of minerals, vitamins, and other compounds in any living things and food. Always take the nutritional values with a truckload of salt. In the case of tea specifically :  “Total catechin content (TCC) for white teas ranged widely from 14.40 to 369.60 mg/g of dry plant material for water extracts […] TCC for green teas also ranged more than 10-fold” [4]. In one of the studies [1] or [2] the authors state very clearly that other groups carrying out similar studies failed to find an improvement in oral health due to green tea. Content variation should be the number one suspect for inconsistencies in results from studies using extracts that are not titrated for their content of active ingredients.So how to hack this variation?

For practical reasons, a pH test of saliva is the best way to know if a green tea extract is potent enough or not. Paper tests can do the job, you want a pH test mostly sensitive for pH in the range the [4.5 to 6] and keep a pH above 6 when following the protocol of the study [1] that I summed up in paragraph 2 of this article. I’m sure there’s even a way to do this pH test with very low-tech means at home without even having to buy paper strip pH tests.
It’s tricky though, because this will work the first time, and if you’re consistent with green tea mouthwash, the pH test will not give you an acidic saliva reading and you’d find yourself confused. Why? There seems to be an increased benefit of green tea mouthwash overtime as described on the pH results in [2], very likely because of a gradual eradication of the acid-forming bacteria  S. mutans overtime  (a single wash cuts S. mutans population in about half in both saliva and plaque [1]). This means you’d have to test your new batches either by using a guinea pig (homo sapiens) that doesn’t use green tea, or by not using your mouthwash for a while, re-allowing your bad bacteria to develop and be able to score you a low pH again of you weer to have a sweet drink. For practical reasons I would go for the latter even if I don’t like the idea of allowing the bacteria population to grow again. So I don’t have to do that too often I would make large concentrated batches I can keep in the fridge. This would assure that I have a lot of a good batch saved whenever I make one.

Additional notes:

1) This article is purely based on a literature review. It provides a prediction of what is expected to be the best method to sustainably achieve with low-tech means a green/white tea extract that is reliably potent. Experiments with the above method are needed to confirm or disprove what I described. The results are of interest to me, so do share in the comments what the results are for you or if you have a question.

2) The could be a possibility of the bacteria S. mutans adapting to the active ingredient in green or whit, rendering the mouthwash useless. Only long-term experimentation will tell.

[1] Int J Dent Hygiene 9, 2011; 110–116 DOI: 10.1111/j.1601-5037.2009.00440.x, “A pilot study of the role of green tea use on oral health”, Awadalla HI, Ragab MH, Bassuoni MW, Fayed MT, Abbas MO.
[2] Indian Journal of Dental Research, 24(1), 2013, ” Comparison of the effectiveness of 0.5% tea, 2% neem and 0.2% chlorhexidine mouthwashes on oral health: A randomized control trial“,  Aswini Y Balappanavar, Varun Sardana1, Malkeet Singh
[3] Nutr Cancer. 2001; 41(1-2): 98–103. doi:  10.1080/01635581.2001.9680618, “Inhibition by White Tea of 2-Amino-1-Methyl-6-Phenylimidazo[4,5-b]Pyridine-Induced Colonic Aberrant Crypts in the F344 Rat“,  Gilberto Santana-Rios, Gayle A. Orner, Meirong Xu, Maria Izquierdo-Pulido, and Roderick H. Dashwood
[4] Unachukwu, U. J., Ahmed, S., Kavalier, A., Lyles, J. T. and Kennelly, E. J. (2010), White and Green Teas (Camellia sinensis var. sinensis): Variation in Phenolic, Methylxanthine, and Antioxidant Profiles. Journal of Food Science, 75: C541–C548. doi: 10.1111/j.1750-3841.2010.01705.
[5] Hasan S, Danishuddin M, Adil M, Singh K, Verma PK, et al. (2012) Efficacy of E. officinalis on the Cariogenic Properties of Streptococcus mutans: A Novel and Alternative Approach to Suppress Quorum-Sensing Mechanism. PLoS ONE 7(7): e40319. doi:10.1371/journal.pone.0040319

11 thoughts on “Science-based Recipe for Green Tea And White Tea Mouthwash

  1. Thank you for the research you did. I found it most useful.

    I think Dr. Greger should have clarified that the tea will be a Camelia Sinensis cultivar not some other green plant or bush which some people may think is the case. I agree with your assessment since my own research pointed to the same conclusion that each batch of tea steeped would have to be tested for PH and there is likely no way of determining just what percentage of catechins are to be found in commercially bought teas. There are likely to be a lot of variables packet by packet or batch by batch.

    Wishing you well.

  2. Hi Charmaine,
    I may be biased here, but I’m curious why some people would think green tea could be something else than Camelia Sinensis. Are there marketed product that sell something else as green tea?
    As for the assessment of the green tea, given the price of a pH-meter (~20$ and above) and merely how fun a pH-meter is, the cost of one will be recovered within a couple of months.

  3. Very complicated; Can you write a simple recipe as to how to make mouthwash with green tea? Lengthy article is fine for those we want to understand nuts and bolts, for lay people, all we need is simple recipe.

    Also isn’t tap water going to go rancid etc if you make your mouth wash for 2 weeks using tap water?

  4. The simple recipe is already in the article:

    For those in a hurry who already decided they would go for it:
    Recipe and instructions for a 0.5%green tea mouthwash :
    Put 5 grams of green tea (or white tea) in 1 liter of room-temperature water, let sit 1 hour and strain. Rinse with 15mL for 30 seconds and spit. Do this after brushing your teeth or before/after a meal. WARNING: Because of the natural variation in the content of active ingredients found in tea leaves, refer to section 6) to know how to test your batch and make sure it will actually work.

    You need to understand why the article is complicated. Plants are not pharamacy drugs, no one tells them to make the same amount of the active ingredient in each leaf.
    So if you do the simple, it’s a better than nothing approach, not an optimal one. And that’s OK, as long as you know this is the limitation there is to this.

    Because of the variation of the (likely) active ingredient in the tea, the rest of the (I agree complicated) article is basically about how to work around that variation. The best other way around the variation is to simply get a standardized extract. But let’s keep things simple:
    I have done this mouthwash and used it, amla definitely extends its “shelflife” (a pinch, I don’t do it very scientifically). I also never make a batch for more than a few days, one week maximum because the taste in the mouth becomes funny any longer than that, rancid as you say.

  5. Thanks Boony for the detailed answer. If you buy a pound of green tea and test pH once, then you can assume it’s going to be same for that particular bag, If you buy another bag, even if the same type, then you need to retest. It’s not like you have to test for each batch of mouthwash. Correct?

    How much amla to add to 1 liter of mouthwash? you said pinch, meaning tsp, tbsp, 1/2 tsp? can you give some reference?

  6. You’re welcome. I have not read my article again to immerse myself into the logic, but from the top of my head:
    “If you buy a pound of green tea and test pH once, then you can assume it’s going to be same for that particular bag.”
    >> It depends on the degree of variation in leaves, if it’s ground or not (homogenized) etc. I would not assume. That’s why the approach I gave is batch-specific.
    How much amla to add to 1 liter of mouthwash? you said pinch, meaning tsp, tbsp, 1/2 tsp? can you give some reference?
    >>For the dosage on amla, I think I tried to get the full-text paper but couldn’t put my hands on it. So I must have done plan B and just used what Dr. Greger had recommended in the video. Can’t remember!
    In short:
    I can see that you really want to get this done very precisely.
    Since I long moved on to other things and am not not likely to explore this further, I take a minute or two putting you on track in you want to push this further.
    When I saw the video from Dr. Greger I was a bit frustrated that there was no simple recipe provided, that’s why I decided it would be a “snack of a mystery” to solve.
    What started as mouthwash problem solving ended up being quite time-consuming.
    It obviously needed (and still needs) just a zest more experimental research to answer all the questions you’re asking.
    I spent far more time than I had planned looking for a very small and inexpensive pH-meter for very small fluid amount, i.e. saliva. I looked into paper tests but nothing was sensitive enough between 5.5 and 7, even the few that were supposed to have most of their shift in color in a range around 5 or 6. Electronic pH-meters most often bulky, and more often expensive.
    I got the smallest I could find for <20$ but it was still quite bulky. If you’re interested in self-experimenting the key is in having a robust way to measure the pH of saliva, or of a very small amount of fluid.
    There are different approaches that can also be done otherwise:
    – doing a bacterial culture instead, less ideal.
    – Using (colored?) reagents that are particularly responsive not necessarily to pH but to the presence of lactic acid or whatever acids may be involved. You would have to know one
    – Asking a dentist if there is a simple test for mouth acidity. I only heard of a blue or red dye test but that was for to stain plaque. Colgate sells on of those, mainly to teach kids how to brush their teeth properly. Kids love colors! Actually, to prove that plaque no longer forms that could be used. It doesn’t help with low pH though which is another expression of the same bacterial problem.

    What do I do now practically?
    I look at the problem differently, it’s a better than nothing approach. Can’t be bothered to put the mouthwash in the fridge, take it out, let it cool then use…so I make frequent smaller batches so that the taste remains pleasant.

    Hope it helps 🙂

  7. Thank you so much for this article and doing the research you did! Really appreciate that!

    A suggestion: Maybe buy a little green tea from many different vendors and different kinds of green tea. That way there is a good chance that at least some of the tea is going to be highly effective, so you’ll get a good cleanse at least once a few times a week. Whereas if you buy a big bunch of one sort, there is a chance you’ll be always swishing with a somewhat ineffective solution… or you could hit the jackpot! 😀 I don’t know if this makes sense. This would, of course, be for people who are not willing the testing described in chapter 6 of the article.

    Anyway, I think the “better-than-nothing” (or “quite-probably-a-lot-better-than-nothing”) mindset is a good one to have in any case! 🙂

    Also, about staining teeth with the green tea swishing, I wonder if swishing with water right after swishing with the green tea mouthwash would help prevent potential staining. But would this also reduce the effectiveness of the green tea mouthwash if the trace amounts of the green tea in the mouth and teeth after swishing are washed out, as maybe there could be additional benefit if the trace green tea can continue to kill a little more S. mutans if not immediately swished away. I don’t know, probably went too far there. 🙂

    Thanks for the article again!

  8. Perhaps oil pulling with coconut oil could prevent or reverse any possible staining? Many people say oil pulling with coconut oil has made their teeth whiter and oil pulling is claimed to have other benefits as well. 🙂

  9. I did question/search “oil pulling” with an open mind, using many different approaches and see if they fit in, I decided there was nothing interesting in oil pulling. This should be rather evident to anyone who look sat the problem not just from the angle of reading the literature and studies, but also looks at the biology of things and see if swishing with oil makes any sense at all. I believe no pulling at all is necessary, and if someone really wants to swish something at all cost, they would harm their teeth far less by swishing water, which again, I believe is unnecessary.

    The paper “Caries: Disease of Civilization”* (or similar title) however does point to why gum stimulation is beneficial, which most naturally should be achieves by the process of eating fibery/hard foods enough. More importantly, dental is health, or rather dental problems are a sort of degeneration from bad nutritional status and/or dental hygiene early in life. A number of post-war observation point to that as well.

    In all cases, in a natural state teeth are supposed to in contact with saliva, a water medium, which in healthy conditions has a pH close around 6~7. Herbivores (that we are) also generally consume foods that are mostly made of water and with a percentage of lipids that is very small, not a 50% emulsion. Humans in particular doing particularly well on naturally occurring low-fat foods.
    This point me once more towards the idea that oil on teeth is a rather unnatural phenomena. Teeth like anything will get shiny when oil is applied on them, and that should never be a clue that its a healthy thing to do. Arteries, which like teeth exchange nutrients with their surroundings, also get shiny when glazed and asphyxiated with fatty meals, that is certainly not a sign that of something good. Hair on the other side, has dedicated sebaceous glands to oil its surface, hence it’s natural to condition hair with fatty substances (hair conditioners are oil-water emulsions) after having stripped the natural oils away with a soap/shampoo etc…There are no sebaceous glands to keep teeth oiled.

    Also, on a more practical angle, people like Dr. Mercola who recommend oil pulling for 20 minuts a day, who is seriously going to keep up with a routine like this one? It won’t be the first time Dr. Mercola rides on something he thinks is great and tell everyone to do it without really using much common sense or doing the proper research. In his favour though, he has posted some very relevant things too, like on the benefits of fasting, but oil-pulling and consuming coconut oil are not some of them.

    * Dental Disease and Civilisation
    By P. J. STOY, B.D.S., F.D.S.R.C.S.
    Inaugural Lecture in the Chair of Dentistry, of the Queen’s University of Belfast

    Effect of oil pulling on plaque induced gingivitis- A randomized, controlled, triple-blind study
    Tooth brushing oil pulling and tissue regeneration – A review of holistic approaches to oral health
    Effect of Safflower Oil on the Protective Properties of the in situ Formed Salivary Pellicle
    Oil-pulling your leg (Science-based Medicine)

    and I hope you can appreciate how serious some early articles on oil-pulling are.
    “Oil pulling therapy”

  10. Is it mandatory to spit out the tea? I realize it seems like a good idea to remove the bacteria from the mouth; but it seems to me that swallowing the tea takes it to the stomach where the digestive environment would kill, and digest the bacteria. The reason for this question is my thought that if one includes swishing with ones tea consumption, this would give a great hygenic boost to the mouth, while finessing the need to create a special batch of tea as a mouthwash.

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