Diet in Relation to Teeth


There are those who maintain that diet has little or nothing to do with the question, and that some families have naturally good teeth while others have bad ones, and that the question is one of heredity. Heredity undoubtedly does much to determine physique and the condition of the teeth is presumably no exception. Nevertheless, the effects of good or bad feeding can be passed on through several generations, and there are probably few cases of dental caries which might not have been influenced by the diet during the ante-natal period or during childhood, and even in later life.

Factors Influencing Caries

It is not enough, then, merely to build healthy teeth, but we must beware of dietary errors which may break down the resistance of decay.

Firstly, the calcium, phosphorus and Vitamin D already mentioned must be present throughout life.

Secondly, excess of cereal, sweets and sugar must be avoided, but this is definitely less important when adequate Vitamin D is present.

Thirdly, an abundance of fresh food should be provided – milk, fruit, vegetables and eggs.

Has Vitamin C the specific influence which some authorities claim with regard to the prevention and arrest of dental caries and pyorrhea? It has been repeatedly found that one pint of orange juice and half a lettuce daily has resulted in the arrest of both these conditions, but that when the treatment was discontinued the caries and the pyorrhea began again.

In the south of England not long ago two patients were treated for gastric ulcer on diets which were seriously lacking in fresh fruit and vegetable. Both returned after a few weeks with loose teeth and infected gums. Extraction was advised, but the respective dentists agreed that a dietitian might try what she could do with diet, and after a few weeks on eight ounces of orange juice daily the gums were healthy and the teeth were firm. In these cases incipient scurvy had probably developed, and this emphasizes the importance of including fresh fruit in the gastric patient’s diet. In cases without scorbutic symptoms it is not easy to prove that it is actually Vitamin C which has been effective in the arrest of caries or pyorrhea, for orange juice contains also Vitamin A, an excellent phosphate and calcium – even the local effect may be beneficial.

Mrs. Mellanby attributes the benefit derived from orange juice as due to Vitamin A rather than to Vitamin C. It will now be possible to repeat such experiments, using pure Vitamin C, for this vitamin, called ascorbic acid, has recently been synthesized in the laboratory. While speaking of Vitamin C it is interesting to note that the symptoms of Vitamin C deficiency can be detected in dental structure of guinea-pigs long before there are any other clinical symptoms of scurvy.

The Influence of Sugar

Have sugar or other fermentable carbohydrates any harmful influence on the tooth due to the local effect of the lactic acid which they produce? This is a question which I am not prepared to answer, but I can tell you that experimentally, when diets have been thoroughly adequate in all respects, reasonable amount of sweets have not been found to make any difference to the incidence of dental caries. On the other hand, when no special attention has been paid to the rest of the diet, several workers have reported that dental caries was proportionate to the amount of sugar eaten.

Since few diets are beyond reproach in their vitamin and mineral content, it seems advisable to eat sparingly of sweets and sugar, which are unnatural foods and which were practically excluded from the primitive diets we have mentioned. Sugar can be obtained in a natural form from dried and fresh fruits and honey. No matter if sugar is harmless in a local sense, a diet containing excessive amounts of carbohydrate is always risky. Sweets and sugar and refined starches satisfy the appetite without providing a balanced meal. The child who has eaten a packet of sweets at 11 a.m. will not eat his dinner when midday arrives. Excessive carbohydrate, then, is apt to crowd out from the diet the more important and protective foods, such as milk, vegetables, eggs and fruit.

May I also mention that in the case of chronic infections, such as catarrh, boils, and also in an ulceration of the mucous membrane of the mouth, I have noticed a marked improvement when all sweets and sugar are temporarily withdrawn and additional Vitamin A is given.

The Importance of Hard Foods

With regard to the importance of hard foods, it is obvious that since we were given teeth we were meant to use them. There is little doubt that hard baked bread, apples, raw carrot, salads and crisp cereals are preferable to cereal puddings and porridge. But I must confess I grudge cutting out porridge from the poor child’s diet, for it gives him a hot meal before going to school. The milk served with it provides the necessary Vitamin D, and an apple or hard baked bread can be given at the same meal. With regard to cereal puddings, they should be given in moderation, and a glass of milk and fruit is a better dessert in summer. Hard foods help to keep the teeth clean and they stimulate the circulation in the gums and they increase the flow of saliva.

We read a lot nowadays about the harmful effects of an acid diet upon the teeth and the beneficial effects of an alkaline diet. I do not believe that it is possible to prove that the alleged benefit is due to the base-forming properties of the diet, for a basic diet is one which provides, at the same time, an abundance of vitamins and calcium, being composed largely of milk, vegetables and fruit. An acid-forming diet, on the other hand, is one which is lacking in these foods, and which contains much meat, fish and cereal. Many dietary factors are therefore concerned in addition to the acid or alkaline reaction of the diet.


One hears a lot of nonsense talked about acid blood or an acid saliva. Anyone with a elementary knowledge of physiology knows that we could not live if the blood were acid, nor is the saliva ever acid. Diet can, however, influence the alkali reserve of the blood, and presumably that of the saliva to a mild extent. It may be true, as some authorities believe, that dietary errors may destroy certain protective agents found in the saliva, but at present there is little proof of this. It seems very probable that indigestion arising from excessive gastric acidity may be harmful to the teeth, and a reduction in starches and sugar, strong tea, fried foods and highly seasoned foods will often work wonders in this respect.

A Satisfactory Diet. – It is not possible for me to give you details of all the diets which have been found effective in controlling dental caries, but it is not surprising to find that they are similar to those which result also in a general state of good nutrition.

The following is a satisfactory diet from every point of view:

Milk: One and a half to two pints for every child and pregnant and nursing mother (use cheese or skim milk as a cheap substitute if necessary). One pint for the adult.
Vegetable: Two vegetables besides potatoes, leafy vegetables and salads being included as often as possible.
Fruit: Two good servings of fresh fruit, one a citrus fruit for Vitamin C. An apple, taking a quarter at the end of each meal. Extra orange juice if afforded.
Eggs: One daily if possible. Not less than four weekly. Herring is a good substitute.
Meat: A helping of meat or fish once daily. This may sometimes be changed for extra cheese or eggs.
Fats: One ounce of butter; the rest of the fat may be of a cheaper variety, for example, suet, dripping or vitaminized margarine.
Cereals: Avoid excess. Take at least half bread and cereal in form of “dark” cereals.
Cod liver oil or a substitute for all children and pregnant women, especially during winter.
Fluid: Water plentifully. Tea and coffee sparingly; omit in case of children.
Tinned foods, jams, sweets and all highly-refined foods to be taken in small quantities only.

British Dental Journal per The Dental Journal of Australia.