Diet for Oral Health

To sum up the relationship between diet and oral well being, Michael Pollan’s words are excellent: "Eat food, not too much, mostly plants."

It’s a useful advice, with some minor additions when it comes to dental health, such as further reduction of starchy carbohydrates and sugar.


By the 21st century, it’s been slowly realized that the standard western diet is not supporting health.

A diet low in carbohydrates, rich in omega‐3 fatty acids, rich in vitamins C and D, and rich in fiber induces significantly lower counts of caries‐ and periodontitis‐associated pathogens and causing a favorable shift in the bacterial micro-flora.


Among the factors in our control, the diet seems to play a major role in our overall health. The same applies to teeth and gums health.


What we consume and how often, determines, directly and indirectly, health and disease.

Nutritional research is notoriously challenging because of the complex, individual factors. It’s becoming increasingly difficult to stay up-to-date in these rapidly changing fields. Yet, the scientific method still seems to be the only solution to improve the quality of life for all of humanity.


The consumption of fermentable carbohydrates, particularly table sugar, has been identified to be directly related to the caries-causing microorganisms and caries risk. A high intake of carbohydrates has been shown to promote dysbiosis and chronic inflammatory diseases as well.


Many effects are direct and local, happening without swallowing the food, just by placing nutrients into the oral cavity. Things like slow but continuous abrasion and erosion of teeth, dysbiosis of the microbiota, inflammation and irritation of the gums or mucosa.


Indirect, systemic effects occur once food enters to lower parts of the gut. This strongly interacts with the general health status and the level of inflammation. Certain vitamins and minerals often get recirculated in the saliva in a higher  concentration, further contributing a healthy, balanced state.

Saliva has several health promoting benefits. From lubrication and digestion to the protection of the teeth and soft tissues around the oral cavity. Lack of saliva, dry mouth is associated with an increased risk of several oral conditions and hugely impact one’s daily life.

Most direct factors act via modifying the oral microbiota (all the microbes living in the oral cavity). Microbial systems seem to play a central role in our lives and recently humans are seen more as holobionts, rather than an independent multicellular organism. A complex unit of different species co-operating in symbiosis.

In a previous post about the changes of the microbiome in the context of human history, it's discussed how dietary shifts toward more processed, carbohydrate-rich diet seems to have the biggest impact on oral health. Food high in sugar and carbohydrates can be digested by certain bacteria forming acidic byproducts that are responsible for tooth decays (caries).




The consumption of more fibrous, chewy food increases saliva flow which is a natural protective mechanism. Muscle movements and grinding keep most of the chewing surfaces clean. The sticky- starchy plaque, that’s formed right after eating processed carbs, is not present.

Some carbohydrates are considered ‘stickier’ than others. Complex, unprocessed carbs such as fiber, are digestible by bacteria and beneficial to the gut, yet don’t cause harm for the teeth.


Less complex, starchy carbs of simple sugars provide easily available food for certain bacteria. The consumption of these causes dysbioses in the microflora and over time leads to the development of new cavities and inflammation.

Streptoccoccus mutans and some other species are well researched for their causal relation to the development of tooth decay. Tooth decay is the most common disease in the world affecting 2.3 billion people. Sugar and high calorie intake from carbs contribute to metabolic syndrome, which as a growing issue affecting 3 out of 5 people in Western societies.

The popularity of juices and fizzy drinks is alarming. These are harmful to the teeth and the to rest of the body, because of the highly acidic pH and sugar content in a dissolved form.

Using appropriate oral hygiene techniques and fluoride were solutions to counter-act these issues, and I will discuss that in the next post about habits and oral health. With some limitations, these measures seemed to slow down the caries pandemic in society, to now being endemic in specific risk groups.

It has been suggested that tooth brushing has been effective in preventing caries mainly because it brings fluoride into the oral cavity at regular intervals, rather than any particular efficiency in disrupting cariogenic plaque biofilms. This emphasizes the importance of a balance diet and microbiota, where pathogens are scarce, and less fluoride is needed.

Mechanical cleaning of the teeth after eating however, is highly recommended, regardless of the quality of food. The less often we eat, the less often we have to clean our teeth. I’ll discuss this more in relation to fasting and intermittent fasting that are becoming increasingly popular for several health reasons.

Certain vitamins such as vitamins C, D, K2 are important for the healthy development and metabolism of teeth and gums. Lacking in these vitamins may lead to less-resistant structures.

Diet may impact the level of inflammation present in the body. It can then modify how the gum’s immune system reacts to the pathogen bacteria that are responsible for gum disease.

During tooth development, an adequate amount of minerals, vitamins, proteins and fluoride is needed to support the process. Too much or too few of those may lead to the weakened enamel structure and surrounding tissue which can increase the risk for cavities or gum disease.

Proper child nutrition and breastfeeding are not just providing nutrients. It’s been thoroughly researched how breast milk, with human milk oligosaccharides and its own microbiome contributes to healthy microbiomes throughout the body. Moreover breastfeeding and later chewing/mastication is important for skeletal and muscle developments.

Making sure that what and how you eat truly supports the microbiota all over the gut, from the oral cavity to the colon is critical for prevention and staying healthy.

From an oral health perspective, it means avoiding sugars and simple carbs, consuming good fats, enough proteins, plants high in fiber and phytonutrients which help to promote probiotics and to reduce inflammation.

Further read and references:

1 comment

  • hi
    I am interested in this topic

    Shawbo Mohamad

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