See Your Dentist Twice a Year




THESE slogans carry the faith of our people. It is said and believed that we Americans have the best dentists in the world, and that we have more toothbrushes, and use them more, than any other people. Many agencies, from kindergarten to university, from town council to and through the governments of city, state, and nation, strive for the spread of dental knowledge and the enforcement of its discipline. For instance, some time ago the New York subways coöperated with the Commissioner of Health by displaying the notice: —

Commissioner of Health

Radio and magazine advertising tell us that mouth chemistry is altered by a paste, a powder, or a gargle so as to prevent decay; that a special kind of toothbrush reaches all the crevices; that a particular brand of fruit, milk, or bread is rich in elements for tooth health. Mothers throughout the land coax, scold, and bribe children to use the preparations, eat the foods, and follow the rules that are said to guarantee perfect oral hygiene. There is endless repetition of the slogan, “A clean tooth never decays.”

Dr. Adelbert Fernald, Curator of the Museum of the Dental School, Harvard University, collected mouth casts of living North Americans of all racial derivations from blond to black, from the most northerly Eskimos through Canada and the States south to Yucatán. He found the best teeth and the healthiest mouths among people who never drank milk since they had ceased to be suckling babes, and who never in their lives tasted any of the other things which we usually recommend for sound teeth.

These people, Eskimos not as yet influenced by white men, never used tooth paste, tooth powder, toothbrushes, mouthwash, or gargle. They never took any pains to cleanse their teeth or mouths. They did not visit their dentists twice a year or even once in a lifetime. Their food was exclusively meat.

Meat, be it noted, was not mentioned as good for the teeth in the advertisement sponsored by the Commissioner of Health of the City of New York. The subway slogans have disappeared, along with the meat, but the dental myths have persisted.

Teeth superior on the average to those of the presidents of our largest tooth-paste companies are found in the world today, and have existed during past ages, among people who violate every precept of dentifrice advertising. Not all of them have lived exclusively on meat; but, so far as my extensive correspondence with authorities has yet been able to show, a complete absence of tooth decay from entire communities has never existed in the past, and does not exist now, except where meat is either exclusive or heavily predominant in the diet.

The key to the situation lies more in the broad science of anthropology. I now give, by sample and by summary, things personally known to me from anthropological field work.

I received my first anthropological commission from the Peabody Museum of Harvard University when it sent John W. Hastings and me to Iceland, in 1905. We found there in one place a medieval graveyard that was being cut away by the sea. Skulls were rolling about in the water at high tide; at low tide we gathered them and picked up scattered teeth here and there. As wind and water shifted the sands, we found more and more teeth, until we had a handful. We got permission to excavate the cemetery, and eventually brought with us to Harvard a miscellaneous lot of bones which included eighty skulls and a great many loose teeth.

The collection has been studied by dentists and physical anthropologists without the discovery of a single cavity in even one tooth. So the Icelanders of the Middle Ages had no toothache, and none of that sloughing away of the teeth which we call dental caries.

The skulls in the Hastings-Stefansson collection at Harvard University represent persons of ordinary Icelandic blood. There were no aborigines in that island when the Irish discovered it some time before the year 800. When the Norsemen got there, after 850, they found no people except the Irish. The Icelanders are therefore a blend of Norwegian and Irish, with some admixture of other northern nationalities. It is now variously estimated that the derivation of Icelandic blood is from 10 to 30 per cent Irish, from 60 to 80 per cent Norwegian, and the rest chiefly Scotch, English, Swedish, and Danish.

None of the peoples whose blood went into the Icelandic stock are racially immune to tooth decay, nor are the modern Icelanders. Then why were the Icelanders of the Middle Ages immune?

An analysis of the various factors makes it pretty clear that it was their diet which protected the teeth of the medieval Icelanders. The chief elements of their food were fish, mutton, milk, and milk products. There was a certain amount of beef and there may have been a little horse flesh, particularly in the earliest period represented in the graveyard. Cereals were little imported and were probably used for beer rather than porridge. Bread was a negligible quantity and so were all other elements from the vegetable kingdom, native or imported.

When Hastings and I were in Iceland, many people still remembered, from the middle of the nineteenth century, a period when bread was more rare than caviar is in New York today. As children they had tasted bread only a few times a year, usually when they went with their parents visiting. Thus the diet was still substantially that of the Middle Ages, although the use of porridge was increasing. The older people with whom we talked did not remember hearing of toothache in their early youth, but did remember accounts of it as a painful rarity about the time when the large emigration to North America started, following 1872.

Soon after arrival in the United States (Wisconsin, Minnesota, Dakota) and in Canada (Nova Scotia, Manitoba), the Icelandic colonists became thoroughly familiar with the ravages of caries. In the United States and Canada they had, before 1900 at the latest, teeth as bad as those of the average nativeborn American.

There is then at least one case of a North European people whose immunity from caries (to judge from the Peabody Museum collection and from common report) approached 100 per cent for a thousand years, down to about one hundred years ago. The diet was mainly from the animal kingdom. Now that it has become approximately the same as average for the United States or Europe, Icelandic teeth show as high a percentage of decay.

I began to learn about another formerly toothacheless people when I joined the Mackenzie River Eskimos in 1906. Some of them had been eating European foods in considerable amount since 1889; toothache and tooth decay were appearing, but only in the mouths of those who ate the new foods secured from the Yankee whalers. The Mackenzie people agreed that toothache and tooth cavities had been unknown in the childhood of those then approaching middle age, while there were many of all ages still untouched — the ones who kept mainly or wholly to the Eskimo foods. Here, and in many other places, this diet is between 98 and 100 per cent from animal sources, if measured in calories — the vegetable food is chiefly berries in season.

There are Eskimo districts, like parts of Labrador and of western and southwestern Alaska, where even before the coming of Europeans considerable use was made of native vegetables. Probably, however, the vegetable element nowhere furnished as much as 5 per cent of the average yearly caloric intake of the primitive Eskimo, even in southwestern Alaska.

Dr. Aleš Hrdlička, the distinguished Curator of Anthropology in the National Museum, Washington, whose death in 1943 was a great loss to American science, wrote me shortly before he died that he had been able to verify no case of tooth decay among Eskimos of the present or past who were uninfluenced by European habits. Dr. S. G. Ritchie, of Dalhousie University, wrote after studying the skeleton collection gathered by Dr. Diamond Jenness on my third expedition: “In all the teeth examined there is not the slightest trace of caries.”

I brought to the American Museum of Natural History, New York, about one hundred skulls of Eskimos who had died before Europeans came in. These have been examined by many students, but no sign of tooth decay has yet been discovered.

At one time it seemed that the record of the Museum’s collection would have to be degraded from its 100 per cent rating; for Dr. M. A. Pleasure examined there 283 skulls said to be Eskimo of preEuropean date and found a small cavity in one tooth. But when the records were checked, it turned out that the collector, the Reverend J. W. Chapman of the Episcopal Board of Missions, New York City, had sent that skull to the Museum as one of an Athapasca Indian, not of an Eskimo.

The Eskimos’ record is, therefore, clean to date. Not a sign of tooth decay has yet been discovered among these people who most completely avoid the foods, the precepts, and the practices favored for dental health by the New York Commissioner of Health, the average dentist, and the dentifrice publicist.


WHEN addressing conventions and societies of medical men, I usually state the oral hygiene case somewhat as I have stated it here, though in more detail. If there is rebuttal from the floor, it frequently takes the form of contending that the tooth health of primitive people is due to their chewing a lot, and to their eating coarse food. The advantage of that argument to the dentist, whose best efforts have failed to save your teeth, is obvious. It gives him an out — that not all your care, even when supported by his skill and science, can preserve teeth in an age of soft foods that give no exercise to the teeth and no friction to the gums.

It is hard to square anthropological findings with this comfortable excuse of the dentist. Among the best teeth of the mixed-diet world are those of a few South Sea Islanders who still keep largely to their native diets. Similar or better tooth condition was described, for instance, from the Hawaiian Islands by the earliest visitors. But can you think of a case less fortunate for the advocates of chewing and coarse diet? The animal food of these people was mainly fish, and fish is soft to the teeth, whether boiled or raw. Among the chief vegetable elements was poi, a kind of soup or paste. They also used sweet potatoes, and yams are not very hard to chew either.

It would be difficult to find a New Yorker or Parisian who does not chew more, and use coarser food, than the South Sea Islanders did on the native diets which are said to have given them, in at least some cases, better than 90 per cent freedom from caries, a record no block on Park Avenue can approach.

There are several obvious reasons why those who never lived with pre-white Eskimos have commonly imagined and frequently stated that Eskimos chew a great deal, and that what they chew is coarse food which gives more massage to their gums than our food does to ours.

People whose diet is in considerable part cereals and other things of vegetable nature almost necessarily chew much; herbivorous animals chew a lot. Also we are educated to chew. For at least five decades we have been taught that painstaking mastication is good for us. We learn from physiology texts in grade school that chewing should mix the saliva thoroughly with the food in the mouth, for digestion begins there. These texts repeat the saw that valiant chewing is good for teeth and gums.

Between the dentists and the Fletcherizers, we of today chew in part from a sense of duty. And dentifrice advertising shows us pictures of charming girls gnawing ham bones or legs of lamb; underneath we read: “Terrible, say the social leaders! Splendid, say the dentists!” The argument proceeds that in an (assumed) previous age people ate meat in the way illustrated by the charming girl, and that they developed and retained excellent teeth through much biting and chewing of tough and coarse food.

These advertisers ignore the fact that man has been a tool-using animal from the first, and that carnivorous primitives have knives. The method of handling meat is about the same whether you are at the beef feasts of the warriors of Ethiopia, as reported in the press and in books of travel, or at the caribou meals of the Stone Age Eskimos as I saw them at Coronation Gulf in 1910. You take a goodsized piece of meat in your left hand and a knife in your right. The knife may be anything from Sheffield steel through native copper to flaked stone. With your front teeth you nip lightly into the edge of the piece of meat, just enough to get a good hold, and then you cut in front of your lips. The piece is not likely to be larger than one we might cut with knife and fork at a restaurant when dining politely on a sirloin.

But, no matter how tender the steak, most of us chew the piece because we have the chewing habit through being partly herbivorous, and because we have been admonished to chew thoroughly. The uncivilized Eskimo has never had practice in herbivorous mastication and his mother has never told him to chew for the good of his health. He gives the piece a bite or two, rolls it around in his mouth once or twice, and swallows. He will, of course, chew efficiently should the piece feel as though it might be hard to gulp down.


THIS description, true of cooked meat, is also true for unfrozen raw flesh, which has in your mouth the feel of a raw oyster and slides down like an oyster — more readily, in fact, for the oyster is likely to be a good bit larger but no more slithery than the piece you cut off for yourself. Raw fish is, if anything, still more like a raw oyster. Boiled fish is soft, though not so soft as if it were raw; so the Eskimo chews it just enough to get it covered with saliva.

When you eat raw flesh in the Arctic during winter, whether it is mammal or fish, you nearly always eat it frozen. Animal tissue at anything like —50° is like glass, and if you drop a fish on a hard floor it splinters. Red meat at these temperatures resembles cast iron in that when you touch it you freeze fast to it. If you were to give even the daintiest lick to a caribou ham at —50°, you would lose a piece of tongue-covering the size of the area which came in contact with the ham.

Obviously that isn’t the kind of frozen food on which we breakfast in the Arctic. We let it lie around indoors until it gets about as soft as hard ice cream. Then we cut it, first into thickish slices and then into smaller pieces, chewing each about as much as one would lumps of ice cream.

With cooked meat, two main causes determine toughness: the age of the animal and the manner of cooking. The chief food animal of the inland Eskimos is the caribou. With them, as with cattle, the older the beast the tougher the meat. A young caribou is as fleet of foot as a heifer; an old one is as slow as a cow. The wolves get the clumsy old ones that drop behind when the band flees, and the Eskimos seldom have a chance to secure an animal that is more than four or five years old. Such young caribou are not tough, no matter how they are cooked. It is the wolves and not the Eskimos who get the tooth and gum benefit (if any) of chewing tough caribou. I do not know a corresponding logical demonstration for seals, but I can testify from helping to eat thousands of them that their meat is never tough — at least not in comparison with the beefsteaks one used to get in New York chophouses.

There is one kind of Eskimo food which gets plenty of chewing — dried flesh. But some districts never have such dried foods at all. In certain districts you would have them one year and not another year. There is no district where desiccated food is likely to represent more than 10 to 15 per cent of the annual diet.

It happens that the districts most prone to dry their flesh foods are the ones which also have an appreciable quantity of vegetables. In Kotzebue Sound, Alaska, for instance, in the early days you were likely to get at the same meal dried fish and masu (knotweed) roots preserved in oil. The fish would take a good deal of chewing and the roots a great deal. This heavy use of the teeth on food which at times had sand in it wore them down to the gums when people grew middle-aged, but no alveolar abscesses were produced, for reasons I shall explain later. Nor was there tooth decay due to the introduction of carbohydrates from the roots; evidently not enough starch was contributed by them for that result. These dry-fish and masu-root eaters, worn of tooth and perhaps a bit unsightly for that, were just as free from caries as the 100 per cent flesh eaters.

Many Eskimos now eat much food that is similar to ours and therefore chew more than they used to. The communities nearest us in diet have the worst teeth, some as bad as ours.

It is a second line of defense for the heavy mastication advocates that, even if Eskimos perhaps don’t chew their food very much, they do chew skins a great deal to soften them. The chewing of leather is, however, far less than you might believe from some authors and certain movies. In any case, skin chewing is done mainly by the women, and it is difficult to see how the wife’s chewing would preserve her husband’s teeth.

Once, at a talk to a medical group, I encountered a further argument: Is it not true that Eskimo men use their teeth in plying their crafts? Do they not bite wood, ivory, or metal to hold, pull out, twist, and so on? The best reply I could think of was to agree that Eskimos pull nails with their teeth, and to follow by suggesting that it is more likely they bite nails because they have good teeth than that they have good teeth because they bite nails.

There are several reasons why the teeth of many Eskimos wear down rapidly. By some anatomical cause their front teeth usually meet edge to edge, where ours frequently overlap, and direct opposition tends to cause wear. Some Eskimos wind-dry fish or red meat; sand gets in and acts like sandpaper. Both sexes, but especially men, use their teeth for biting on hard materials. Both sexes, but especially the women, use their teeth for softening skins. A wearing toward the pulp may, therefore, take place in early middle life. What happens is stated by Dr. Ritchie with relation to the Coronation Gulf Eskimos: —

“Coincident with this extreme wear of the teeth the dental pulps have taken on their original function with conspicuous success. Sufficient new dentine of fine quality has been formed to obliterate the pulp chambers and in some cases even the root canals of the teeth. This new growth of tissue is found in every case where access to the pulp chambers has been threatened. There has therefore been no destruction of the pulps through infection and consequently alveolar abscesses are apparently unknown.”

So total absence of caries from those who live wholly on meat is definite. Cessation of decay when a person transfers from a mixed to a meat diet happens usually, perhaps always. The rest of the picture is not so clear.

Caries has been found in the teeth of mummies in Egypt, Peru, and in our own Southwest. These semiancient peoples were mixed-diet eaters, depending in considerable part on cereals. Their teeth were better than ours, though not so good as those of the Eskimos.

It appears that if you want a dental law, you can approximate it by saying that the most primitive people usually have the best teeth, but that no people of the past or present are known who had complete freedom from tooth decay unless they were a hunting, fishing, or pastoral people and got little or none of their food direct from the vegetable kingdom. You might add that in some cases a highly vegetarian people, while not attaining the 100 per cent perfection of meat eaters, do, nevertheless, have very good teeth as compared with ours.

Incidentally, the definite correlation of tooth decay with the eating of starches and sugars makes any cavities discovered in the teeth of skeletons exhumed by archaeologists a clue to their former way of life. Men, it is universally assumed, were in the earliest stages hunters and gatherers; later they became herdsmen and farmers. The change from hunter to herdsman did not bring with it decay of the teeth; the change to farming did. So when you find a skeleton with decayed teeth, there is the presumption that you have a farmer or at least the victim of an agricultural civilization. For in most parts of the world gatherers would have a time finding enough carbohydrates to ruin their teeth.

It is contended by the Hawaiian Sugar Planters Association Health Research Project that the shift from good to execrable teeth among the mixed-diet Polynesians has been due to a change from the native taro and yam to cereals. I have seen no comment of theirs upon the doubtless great increase of sugar consumption which has been at least as synchronic with the deterioration of Hawaiian teeth as the shift from yams to cereals.


THOSE who seek explanations for the relative soundness of the teeth of hunting and pastoral man, as compared with those of the eaters of mixed diets, have suggested that the temperature at which the food is eaten may have something to do with it. Certainly there are few differences more striking than those between the usual temperatures at which the Eskimos and we eat and drink.

In the drinking of water the primitive Eskimo was about even with those of us who usually chill our drinks. In summer he would dip water off the surface of sea ice, or he would drink from rivers which, although by no means ice-cold, were on the average colder than ours. In winter, when he melted snow or ice, he would usually put snow or ice back in his water before drinking if it was appreciably warm.

The primitive Eskimo had nothing to correspond with the tea and coffee that many of us gulp almost scalding hot. He did have broths to correspond with our soups; we like them almost as hot as our tea, but he would set his aside to cool down to what we think of as lukewarm.

There was the same difference in cooked food. We like our meats almost as hot as our drinks, and so with baked and boiled potatoes and many other things. Cut the Eskimo housewife was not supposed to offer a piece of meat to a guest, or to a member of her family, until by repeated touching she had ascertained that it was nearly as cold as her hand. True, this rule was not always observed, particularly where appetites were keen or where children or others of small patience were concerned.

It was not true, as implied by the usual movie and by some writers, that Eskimos preferred to eat their food raw. A few things were preferred raw, among them seal liver; but most were preferred boiled or roasted, and if they were eaten raw it was usually for convenience. Still it is true that they ate wholly uncooked meats more frequently than we do.

On the north coast of Alaska, and of western Arctic Canada, on our first expedition, 1906-1907, and again on the second expedition, 1908-1912, we saw among the local Eskimos the transition from their methods of cooking and eating to ours. Even in 1906 there were a few who drank very hot tea, and these were proud of the accomplishment; the rest were something like people learning to eat green olives, proud of each slight advance in ability to tolerate the new experience. It was striking that, in the early years, the eating of very hot foods and the drinking of very hot drinks were strictly confined to those introduced by the whites. The same man who drank his tea nearly scalding, with seeming enjoyment, would be as careful as he ever had been that his broth should be lukewarm. Those who ate doughnuts piping hot from the grease would see to it that a chunk of boiled caribou was cooled nearly down to body temperature.

It happens that in the matter of hot foods and drinks there was in Iceland about the same kind of change as among the northern Canadian Eskimos at the time when caries began to appear. The drinks of the early Icelanders were milk, whey, and to a small extent beer. They resembled the average European, and differed from the Eskimo and modern American, in that they drank relatively little cold water. Their milk was sometimes heated, but there was nothing to correspond with the large volumes of hot liquid which began to be taken when the coffee habit developed, in the first half of the nineteenth century. There was probably also at least a slight increase during the same period in the eating of cooked things, and probably the very custom of drinking hot coffee tended to increase the taste for higher temperatures in food generally. Still it is clear that before the introduction of coffee the Icelanders consumed far more hot food than did the Eskimos prior to the introduction of tea.


WE DO not have, then, as to the change in food and drink temperatures, with either the Eskimos or the Icelanders, the clarity of a test under laboratory conditions. Among the Eskimos sugar and starch were being introduced, as well as new forms of protein, during the period when tea and hot foods were being introduced, so that the shift from an approximately 100 per cent meat diet to a mixed diet, and the shift from colder to warmer foods and drinks, both coincided about equally with the beginning and then the rapid increase of dental caries. The same double and overlapping correspondence held true to a less extent when the Icelanders were shifting from a diet which had been chiefly mutton, fish, and milk to one high in sugar, starch, and proteins of vegetable origin.

Everyone agrees that, although there is probably no racial difference, there certainly is a considerable individual difference with regard to tooth decay. While it seems that Eskimos, Scots, and Zulus have caries about in relation to the chemistry of the food they eat, if large numbers are averaged, it is equally true that members of a single household, though blood relatives, who appear to eat nearly the same food, may differ greatly in the soundness of their teeth. This seems equally true where the brushing of teeth is cultivated and where that practice is unknown.

To sum up, the only thing that matters greatly with regard to the health of the teeth is the chemical composition of the diet — the higher the percentage of carbohydrates and the lower the percentage of animal proteins and fats, the greater the tooth decay.

Pending further study, however, I had better be a little cautious here and say that, while we do know that diets the calories of which are 98 per cent or more from animal fats and animal proteins will guarantee you against caries, we do not know for sure that a 75 per cent meat diet, with 25 per cent of carbohydrates, is much better for the teeth than one that is 50 per cent meat and 50 per cent carbohydrates. It may be that you would have to confine yourself to meats, supplemented if desired by dairy foods and eggs, if you wanted to be sure of avoiding the dentist permanently.

There are scientists (for instance, Professor L. M. Waugh of the School of Dental and Oral Surgery of Columbia University) who are of opinion that while carbohydrates produce tooth decay, the starches among them are relatively innocent, the practically exclusive villains being the sugars. This view is a little hard to reconcile with the fact that, upon digestion, starch turns into sugar. Still, as I said, there is at least a ground for suspending a blanket judgment against all the carbohydrates, lest some be found in deeper sin than others.

It has been pointed out, for instance by Dr. Henry B. Collins, Senior Ethnologist of the Bureau of American Ethnology of the Smithsonian Institution, that the incidence of caries seems to be heavier among those primitive peoples who get their starches from cereals than among those who get them from yams and potatoes. There appears little reason to doubt that there were people in the South Sea Islands who had a considerable starch percentage in their diet, obtained from things like yams and poi, and who nevertheless had better teeth than the corn eaters of the North American plains or the small-grain eaters of Babylonia and ancient Egypt.

We have not yet had any excitement in the newspapers over the discovery, or the alleged discovery, that no one has caries who lives on meat, whether or not it is supplemented by milk and milk products; but now and then there is a furore in the press because a community has been found where no one has caries, allegedly because of a special chemical composition of the water. This seems to mean that people are not interested in protecting their teeth by changing their food, but that they are interested in protecting them by changing their drinking water.

This may be one more case of a fundamental, subconscious wisdom in mankind. If we face the issue of whether to protect our teeth by an all-meat diet, serious questions arise.

Teeth are only teeth. A good set is mighty handy, but there are not many who fear the dentist so much that they would care to make avoiding him the chief concern in life. False teeth, individually or by the set, are getting better and much cheaper.

Moreover, meat is costly. Ask the price of six pounds of lean sirloin steak and a pound of suet, for that is about what you will need if you work hard through a long day. You could do with cheaper cuts, but many of these are bony and you would require more pounds of them.

Finally, if we all started living exclusively on meat, to protect our teeth or for some other reason, we should soon come to the end of the world’s food resources. The most fundamental of all the reasons why it is better to live on pork and corn pone than on pork by itself is that if we first feed the corn to a pig and then eat the pig, we waste something like six sevenths or seven eighths of the food value of the corn — not thinking, for the moment, of vitamins, minerals, and things of that sort, but merely of caloric value.

There are, of course, many other good reasons why the world is not about to become one federation of carnivores — among them religious prohibitions (as in India), mixed-diet beliefs, established food habits. The main thing is that it couldn’t be done anyway; for we should not be able to produce enough meat in the world, at least not by old-fashioned methods, such as ranching cattle or hunting moose.

The practical objections, however, do not lessen the academic interest of considering how things are and what follows when you omit from your diet sugars, starches, and all that comes direct from the vegetable kingdom, and start living on meat, either exclusively or in combination with things like eggs and milk. A part of the result is that you will then have teeth which remain sound throughout the longest life and that you will visit your dentist, if at all, only for cosmetic purposes—and, of course, for things like impacted teeth and pyorrhea; for it is only caries that you avoid by avoiding carbohydrates.