Illustration by Daria Krikunova

The warmer months of the year usually bring us a steady revival of quick fitness and diet plans, alongside good intentions for the coming summer. These days, there seems to be a special diet plan that tackles almost every purpose or food group. Many have entire philosophies behind them, while others just go for quick results or a quick “reset” of your health.

These trendy diets are often easy to find, but difficult to test. Plus, they are sometimes contradictory or sharply opposed to each other. Explaining the full repercussions and advantages of each trendy diet out there would be a monumental task, and one best left to your family doctor. That's why we have prepared a quick guide on the effects of each diet on your teeth and gums – plus a few tips meant to protect your mouth.

The Vegan Diet

Unlike most fad diets, the vegan lifestyle is as much about health as it is about ethics. The key to vegan diets is to avoid all products that come from animal sources. In addition to meat and eggs, this also means staying away from dairy and honey. This makes the diet low in fat, but high in fibre and on many vitamins.

How does it affect your oral health?

Vegan and vegetarian diets can be very healthy, but they also carry a higher risk of specific nutritional deficiencies, such as calcium, iron, and some types of B-group vitamins.

These micronutrients all play a very important role in bone health, especially for the long term. A large study published in 2007 found that while meat eaters, pescetarians and vegetarians all had the same risk of suffering from bone fractures during old age, vegans were at an increased risk (1).

Teeth are technically bones, although they lose calcium at a much smaller rate than other bones. This may be why some studies have found that vegans have a higher chance of developing white spots and tooth decay later in life(2).

What can you do about it?

The best way to prevent these issues is awareness. There are many plant-based sources of calcium and iron out there, and it will just be a matter of making sure they are included in your diet. Extra calcium supplements can also help.

The Paleo Diet

Followers of the Paleo diet aim to follow the same eating habits as our ancestors from pre-agricultural or Paleolithic times, which lasted through most of human history. In practical terms, this means disregarding heavily processed foods, grains, and flour products. Instead, the Paleo lifestyle offers free-range meats, nuts, fruits, and leafy veggies.

How does it affect your oral health?

Supporters of the Paleo diet often claim that this diet is great for teeth, as it is naturally low in sugar and pastries. That being said, there have been no studies that confirm this, or that have pointed at any oral health problems caused by the Paleo diet. Plus, some archaeological findings show that hunter-gatherer tribes did have tooth decay (3).

What science does show is that while eating less sugar is good for preventing cavities, it doesn’t quite make you immune (4).

What can you do about it?

It’s better to be safe than sorry in this case: keep to your oral hygiene routine as if you were following a normal diet. That means brush, floss, and see your dentist regularly!

The Keto Diet

The keto diet is one of the most controversial, yet rapidly growing diets of this decade. This diet consists basically of keeping carbohydrate intake to a minimum (usually, less than 50 grams a day) to induce a state known as ketosis. In ketosis, the body burns fats rather than carbohydrates for fuel. This process creates ketones that can be then found in urine, blood, and saliva.

How does it affect your oral health?

The keto diet has many side effects, which tend to be especially noticeable at first. Many of these are a direct result of the ketosis process or the presence of ketones, so many new Keto converts will often be on the lookout for them.

One of the best-known ones is a strong acid or vinegary smell on one’s breath. This is known as “keto breath” and happens when your body is trying to dispose of these ketones. This symptom is common enough that some diagnostic tests use breath as a way to test if the diet is working (5).

Other common side effects of the keto diet include dehydration and a dry mouth. These tend to be especially strong during the first few weeks on the diet and can increase your risk of developing cavities (6).

What can you do about it?

Make sure you stay hydrated while on the keto diet. Carry a bottle of water with you until your body gets the hang of it. As for the keto breath, it’s best to pack a toothbrush to work.

Intermittent fasting

Intermittent fasting or “IF” is more of an alternative eating schedule rather than a proper diet. However, it is often used alongside other diets, especially the Paleo diet. Intermittent fasting replaces the standard schedule of three main meals a day for an eating window of just 6, 8 or 12 hours. Proponents of Intermittent Fasting believe this helps increase insulin sensitivity. It also provides you with the pleasure of one hearty meal when you won’t need to watch your portion size so much.

How does it affect your oral health?

Depending on what you eat during that 8-hour window, an intermittent fasting regime can be as balanced as you make it. This diet has not been directly linked to any negative effects on your gums or tooth decay (7). However, fasting can hinder your hydration levels and cause a dry mouth, which in turn can speed up tooth decay.

What an IF regime does achieve for your mouth is that it simplifies your oral hygiene routine a lot. Few people manage to brush after every single meal and snack.

What can you do about it?

If you are following an Intermittent Fasting schedule properly, make sure you brush at the start and end of your eating window. If you feel your mouth turns dry, drink more water or try chewing some sugar-free gum.

Juice cleanses

Juice cleanses are a pretty radical way of losing weight quickly. Most of them require you to spend a short period of eating nothing solid. Instead, you are only supposed to drink fruit juices or vegetable smoothies. This is meant to help you cut down on calories. Depending on the actual juice recipe, they may also say that they can help you “detox” or get rid of fluid retention.

How does it affect your oral health?

Juice cleanses can be very unbalanced. Prolonged or frequent use of these diets can result in severe nutrient and protein deficiency. This is not good for any part of your body, teeth included. Skipping on solid meals can bring problems of its own, as it lowers your saliva production. Saliva helps keep acidity in your mouth in check, which in turn helps you prevent tooth decay and erosion (8).

Depending on the type of cleansing you are following, the juice itself could harm your mouth. Many are very acidic, and some even mask that with extra sugar. Acidity is a major player when it comes to tooth decay, as it progressively erodes your teeth. If you are prone to canker sores, the extra acidity may also cause them to flare up.

What can you do about it?

Don’t brush your teeth right after your super sour juice: the enamel will be a bit “softened” by the acids and lose some mineral tissue. Instead, rinse your mouth with water first, and wait a bit before your usual routine. You can also try using a straw, as this may protect your mouth from the juices’ acidity.

Trendy diets and fad eating plans tend to get revived every few years. Both your general and oral health will be best served by consistent and balanced changes. Make sure you involve your family doctor on any permanent diet decision you make – and keep our tips in hand so your mouth can make the most of your decision.


1. Appleby, P., Rodd-am, A., Allen, N. et al. Comparative fracture risk in vegetarians and nonvegetarians in EPIC-Oxford. European Journal of Clinical Nutrition 61, 1400–1406 (2007). Available online:

2. Laffranchi L, Zotti F, Bonetti S, Dalessandri D, Fontana P. (2010)Oral implications of the vegan diet: an observational study. Minerva Stomatologia. 2010 Nov-Dec;59(11-12):583-91. English, Italian. PubMed PMID: 21217622. Available online:

3. Humphrey L, De Groote I, Morales J, Barton N, Collcutt S, Bronk Ramsey, C, Bouzouggar A. (2014) Earliest evidence for caries and exploitation of starchy plant foods in Pleistocene hunter-gatherers from Morocco. Proceedings of the National Academy of Sciences Jan 2014, 111 (3) 954-959; DOI: 10.1073/pnas.1318176111 Available online:

4. Moynihan PJ, Kelly SA. Effect on caries of restricting sugars intake: a systematic review to inform WHO guidelines. Journal of Dental Research. 2014 Jan;93(1):8-18. DOI: 10.1177/0022034513508954. Available online:

5. Güntner, A. T., Kompalla, J. F., Landis, H., Theodore, S. J., Geidl, B., Sievi, N. A., Kohler, M., Pratsinis, S. E., & Gerber, P. A. (2018). Guiding Ketogenic Diet with Breath Acetone Sensors. Sensors (Basel, Switzerland), 18(11), 3655. Available online:

6. Sinha SR, Kossoff EH.(2005). The ketogenic diet. Neurologist. 2005 May;11(3):161-70. Review. PubMed PMID: 15860138. Available online:

7. Veronese N, Reginster JY. The effects of calorie restriction, intermittent fasting and vegetarian diets on bone health. Ageing: Clinical Expert Research. 2019 Jun;31(6):753-758. DOI: 10.1007/s40520-019-01174-x.

8. Mayo Clinic. (2018) Dry Mouth: Symptoms & Causes. Accessed on May 5th, 2020. Available online:

#vegan #paleodiet #ketodiet #fasting #juicecleanses #intermittentfasting #dentalcare #vegetariandiet #teeth


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