Bone Mineral Content of North Alaskan Eskimos.

[Darryl Shaw]

Bone mineral content of North Alaskan Eskimos

ABSTRACT: Direct photon absorptiometry was used to measure the bone mineral content of forearm bones in Eskimo natives of the north coast of Alaska. The sample consisted of 217 children, 89 adults, and 107 elderly (over 50 years). Eskimo children had a lower bone mineral content than United States whites by 5 to 10% but this was consistent with their smaller body and bone size. Young Eskimo adults (20 to 39 years) of both sexes were similar to whites, but after age 40 the Eskimos of both sexes had a deficit of from 10 to 15% relative to white standards. Aging bone loss, which occurs in many populations, has an earlier onset and greater intensity in the Eskimos. Nutritional factors of high protein, high nitrogen, high phosphorus, and low calcium intakes may be implicated. Am. J. Clin. Nutr. 27:916-925, 1974.

Eskimos throughout the circumpolar regions have a diet highly dependent on animal foods, and the Eskimos of the north coast of Alaska in the past and even today have among the highest meat intakes. Caribou, sea mammals, fish, and birds constitute staple foods, and the supply is generally adequate. though seasonal variation does exist. This dependence on meats provides high intakes of protein and fat (and of course nitrogen. phosphorus. sulfur, and acid); there was a low intake of carbohydrates until the current importation of manufactured foods. Recent nutritional investigations of Alaskan Eskimo populations have generally shown adequate intakes of all major nutrients and little biochemical evidence of poor nutritional status (I ---ı5), except for some anemia and marginal vitamin B6 excretion in younger subjects.

Growth and development from early infancy on appears normal for a group with small adult stature. Eskimos seem to tolerate their dietary fat (6, 7) but have difficulties in handling carbohydrates to which they are relatively unaccustomed; both sucrose and lactose intolerance have been demonstrated in Alaskan and Greenland Eskimos (8-10), and impairment of glucose tolerance exists in Canadian Eskimos (11). Eskimos, and even whites in the Arctic, seem to tolerate the high meat diets well, but the long-term effect of this diet in particular on mineral metabolism has not been studied, although it is well-known that a meat diet, or high intakes of phosphorus or acid, will cause calcium loss. Meat diets have been shown to cause bone rarefaction (12), and among humans, vegetarians have less aging bone loss than omnivores (13). It was therefore of interest to examine the skeletal status of Eskimo natives of the Alaskan north slope.

http://www.ajcn.org/cgi/reprint/27/9/916

[Craig Van De Walker]

I have a question or possibly just food for thought. Have patience while I slowly get to my questions.

I realize that "bone density" is always discussed in terms of "mineral content". Bone however has many components some of which can be quite strong in both tension and compression. I like to think of the horn of a ram which seems quite strong but is not made of primarily calcium. The question I have is that yes the mineral contact of this population seems to be slightly less especially in the older group.

1-Does that in any way prove that Eskimos bones are any less strong?
2-Could they possibly have a proportionate increase in the other structural components that make up bone.
3-Is the assumption being made that all population bases have the exact same bone development (by that I mean exactly the same proportion of each bone constituent)

They have lived in that environment for many generations they would have had a lot longer to develop a slightly different physiology to low calcium availability than modern man has had time to adjust to a diet of processed food.

[Allen Yeh]

Interesting, I wonder how the whole light thing affects them? I know there has been a lot of stuff recently about Vitamin D and bone density. What dietary sources of Vitamin D are they getting as well as how would months of no sunlight be handled as the generations go on?

[Craig Van De Walker]

They have a great food source of vitamin-D "real" fish oil. I don't know but assume they are better off than those of us us that live away from the poles but don't live on fish and seafood.

[Steven Low]

Originally Posted by Craig Van De Walker

They have a great food source of vitamin-D "real" fish oil. I don't know but assume they are better off than those of us us that live away from the poles but don't live on fish and seafood.

Yup, fish has loads of Vitamin D.

Well, not as much as you can supplement... but more than I or you would get unless we worked outside or were outside for good periods of time on a daily basis.

Remember, they don't get much sunlight or dairy so they gotta get it from somewhere.

[Mike ODonnell]

Was going to comment on this thread until I read this above

Meat diets have been shown to cause bone rarefaction (12), and among humans, vegetarians have less aging bone loss than omnivores (13)

Sigh.....I'm out.