A good paper showing the epidemiological relationship between cereal
grain consumption and caries incidence is: (Sreebny LM.  Cereal
availability and dental caries. Community Dent Oral Epidemiol
1983;11:148-55).   The author, Leo Sreebny, did most of the original
epidemiological work relating sucrose consumption to dental caries.

QUESTION:

        In our group over the last month or so, we have bandied about the idea
of the ancestral macronutrient compositions (i.e. %fat, %protein, % CHO)
and how they influence health.    Clearly, in the normal western diet
(~45-50% CHO, 35-40% fat and 10-15% protein) if dietary saturated fats
are reduced, then total and LDL cholesterol are also reduced.   Keys
(Keys A et al.  Serum cholesterol response to changes in the diet. IV.
Particular saturated fatty acids in the diet.  Metabolism
1965;14:776-87) has published an equation which has been used
extensively to predict changes in serum cholesterol from dietary lipids
and cholesterol.    Others (Mensink et al) more recently,  have
confirmed Keys' Equation.    In perhaps the most well controlled,
modern, dietary study of Greenland Eskimos, Bang and Dyerberg (Bang HO,
Dyerberg J.  Lipid metabolism and ischemic heart disease in greenland
eskimos.  In: Advances in Nutrition Research, HH Draper (Ed), Vol 3,
N.Y., Plenum Press, 1980, 1-22.), it has been shown that ischemic heart
disease is very uncommon in these people (3.5 %  vs 45-50% mortality
rate in western countries).    The dietary macronutrient content of
these partially westernized eskimos was (38% CHO, 39%fat and 23%
protein) whereas the values for the control group of Danish people was
(47% CHO, 42% fat, and 11%protein).   Mean total cholesterol levels in
the eskimos (5.03 mmol/liter) was significantly lower than in the Danes
(6.18 mmol/liter) whereas the TG (0.57 vs 1.23 mmol/liter) and VLDL
(0.43 vs 1.29 mmol/liter) were much  lower in the eskimos and HDL levels
were significantly higher (4.00 vs 3.34 mmol/liter).
        Based upon the Keys et al. equation, the actual difference between the
Eskimos' total cholesterol levels should have been 0.67 mmol/liter,
whereas in acutality it was 1.15 mmol/liter.   This data suggests that
the Keys equation may be invalid under circumstances wherein high
quantities of animal products replace traditionally cereal dominated
diets.   Possible reasons for this discrepancy include: (1)  higher
protein levels in the face of lowered CHO may induce different
lipoprotein transport mechanisms (Wolfe BM.  Potential role of raising
dietary protein intake for reducing risk of atherosclerosis. Can J
Cardiol 1995;11:127G-31G) or different polyunsaturated fat (high N3 fats
and high levels of preformed long chain fats of both N3 and N6 families)
between the two diets (Nelson GJ et al.  Low fat diets do not lower
plasma cholesterol levels in healthy men compared to high fat dits with
similar fatty acid composition at constant caloric intake. Lipids 1995
30:969-76).
        The bottom line here is that present day hunter gatherers maintain
quite low serum lipid levels despite high consumptions of animal based
foods.   Comments?

                                        Cordially,


                                        Loren Cordain, Ph.D.