Caries, a strictly bacterial disease, cannot occur unless adequate pabulum —sugar or sugar-yielding material—is present in the mouth for growth of the related bacteria. Predisposing systemic conditions, which imply existence of general resistance or susceptibility to caries, account for sugar tolerance without caries in some individuals, and in the same person at different periods. Regardless of systemic factors, however, caries cannot occur unless the exciting cause is active in the mouth. Primitive Eskimos of Labrador and Alaska (1921-38), on native diets of proteins and fats, and little or no fermentable carbohydrates, are free from caries. The author’s studies among these Eskimos (300 in Labrador ; 3500 in Alaska) have shown conclusively that caries does not occur in primitives until White man’s food is taken to them. The foods first taken to Eskimos by White man consisted principally of white flour and sweets—molasses, refined sugars and candies of various kinds. Eskimos are ” passionately” fond of sweets—especially the children, who eat them continually when procurable. The caries-producing influence of sweets has been shown in separate families—some children receiving candy had carious teeth, while the other children in the family, who had not eaten candy, were free from caries. When sweets are procurable, Eskimo children’s teeth develop caries in a surprisingly short time, and at a rate as rapid and extreme as in children in the United States. Eskimo foods containing flour do not cause caries in the absence of refined sweets. Variations in native or wild foods, in different districts, seem to have no influence on incidence of caries. The findings with hitherto immune Eskimos indicate that caries can be induced in any person, no matter how strong his resistance may be, by feeding refined sweets, especially such as adhere to the teeth (candy, molasses, sugar). Sweets although not the only factor, are the most concentrated and active, either separately or mixed with other foods. This conclusion led the author to offer this helpful slogan for caries prevention, to be popularized among the laity : ” An unsweetened tooth cannot decay.”
In Labrador (1921-37), caries was found only in Eskimos who had been eating White man’s foods, of which refined wheat-flour and pilot-bread, hard-tack, and sea-biscuit, were the first to be consumed—long before 1884. Caries was unknown before 1900, when molasses and sugar were introduced by traders. The principal native foods are seal, walrus, whale, caribou, polar bear, fish, birds and their eggs, eaten raw (frozen in winter). Until recently only the most prosperous
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hunters could procure ” store ” foods in small quantities. The incidence of caries in the most southern missions of Makkovik and Hopedale, where approximately 33 percent of the diet consisted of carbohydrates, was 2.7 percent (of teeth) in thirty-seven old adults ; in twenty-two young adults, 18 to 25 years old, it was 10.5 percent ; in children under 14 years—teeth and gums deplorable, dentoalveolar abscesses common, much extraction by missionaries—it was over 40 percent. Every child under 14 had some caries. In the most northern missions in Hebron (Nain region), where 18 percent of the diet consisted of carbohydrates, caries occurred in 4 percent of the teeth of forty-eight adults ; the percentage was 11 in seventeen children under 14 years. In the Ungava Bay (Port Burwell) district, beyond northern missions—where about 8 percent of the diet consisted of carbohydrates and very little sweets-2283 teeth in seventy-six primitive nomadic Eskimos, all ages, had only 6 cavities-0.26 percent of caries.
In Alaska (1929-1938), in the Arctic and North Bering Sea regions, and Tundra district of the Kuskokwim-Yukon Delta and adjacent islands, conditions were practically the same as those in Labrador. The principal native foods are reindeer, whale, walrus, seal, caribou, fish, birds and their eggs, eaten raw (frozen in winter). In the most northern parts of Alaska, there are no berries or vegetables. In the Kuskokwim-Yukon Delta, in some years, berries are eaten fresh for three or four weeks, and small supplies are commonly stored for the winter ; but, without sugar or other preservative, they usually ferment before use. Pilot- bread, sea-biscuit and hard-tack, were first consumed in 1886, in small quantities —introduced, in the lower Kuskokwim, by Moravian missionaries. At that time there were no trading-posts or other sources of supply of bread. In 1904, the supply of pilot-bread was increased and refined wheat-flour introduced. White sugar and brown sugar were supplied in small quantities in 1906, but only a few of the most prosperous natives could obtain them. Caries, first noticed in this region in 1914, has increased in direct ratio to the amount of sweets consumed by each individual. ” Sugar-free natives ” have remained caries-free (winter of 1937).
In a study in the lower Kuskokwim River-Hooper Bay district (winter of 1935), among the most primitive Eskimos, Donald B. Waugh and the author found that in 223 mouths (cultured) caries was identical bacteriologically with that in White man. Lactobacilli were present in large numbers in all cases. In more than 85 percent of caries-free mouths, lactobacilli were entirely absent ; in 14 percent, a few lactobacilli were present. In 1936, Theodor Rosebury and the author, in an extension of this work, found that 80.6 percent of carious mouths contained lactobacilli and 86.4 percent of caries-free mouths contained none. In 1938, the author and his son conducted—in three settlements on the lower Kuskokwim River in southwestern Alaska—a study of 46 Eskimos of different ages on native diets containing sugar. One group-22 (15 caries-free)—received natural sugars; a second group-24 (11 caries-f ree)—received refined sugars. Periods of observation were five to six weeks for most individuals. In the group on nat‑
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ural sugars, no new cavities developed; there was no increase in oral lactobacilli ; and carious mouths showed normal progress in caries. In the group on refined sugars, caries was initiated in a large proportion of mouths ; at the end of the test each mouth contained lactobacilli ; and there had been marked progression of existing caries—an average of 3.6 cavities per mouth.
In no case, however isolated, was caries found in Eskimos (approximately 1200) who had not received such sweets as sugar, candy and molasses. In a Kipnuk family, the elder and younger sisters were free from caries, while a favorite brother aged 9—who had accompanied his father to the trading post in Bethel for several weeks, in two succeeding summers—showed active caries ; yet in that settlement of 184 natives, only four other children had caries and only to a very slight degree. Refined wheat-flour and pilot-bread were available at this settlement to all who could pay for it, but only those who also consumed considerable sweets had caries. The flour was used to make hard, pan-fried bread about 1/4 inch thick, somewhat like ” ry-krisp,” which formed only a small proportion of the diet. Flour was mixed with water into batter resembling that used by White man for pancakes. A few who could buy baking soda used it, making slightly less brittle bread about 1/2 inch thick. This bread is often kept for weeks before being eaten; becomes very hard on drying; and rugged chewing is required to crush and soften it in saliva.
References: J. Den. Res. (Proc. Int. Assoc. Den. Res.), 1928, 1930, 1931, 1932, 1933, 1936, 1937, 1939; J. Am. Den. Assoc., 1937; Am. J. Dis. Child., 1939.