FIRE:

It seems we have had numerous discussions in this group about the
origins of fire with a multiplicity of references.   Since our genus
Homo, now dates to ~2.33 MYA (1) and since everybody is pretty much in
agreement that the appearance of hearths signals the first regular,
controlled use of fire, then regular cooking probably did not occur
until this event transpired.   James, in his comprehensive review (2)
indicates that no structured  hearths are found until the appearance of
Neanderthals at the end of the middle pleistocene.   Therefore, for most
(~90%) of the evolutionary history of our genus, cooking of food was
rarely if ever done.   It seems likely that the earlier use of fire may
have occurred by capturing and controlling natural fire, however, it is
doubtful that the ability to make fire occurred until much later.   The
antinutrients in raw egg white still impair modern human nutrition, just
like they did to our ancestors, and allergy to eggs remains one of the
most frequently occurring allergies (3).   Clearly, we have had
insufficient evolutionary experience as a species to adapt resistance to
the proteins in this  food.

                                References

1.      Kimbel WH et al.  Late pliocene Homo and oldowan tools from the
Hadar formation (Kada Hadar Member), Ethiopia. J Hum Evol
1996;31:549-61.
2.      James SR.  Hominid use of fire in the lower and middle
pleistocene.  Curr Anthropol 1989:30:1-26.
3.      Noma T et al.  Cytokine production in children outgrowing hen
egg allergy. Clin Exp Allergy 1996;26:1298-1307.

LACTOSE:

        In response to Jennie's inquiry regarding lactose as an
epidemiological  risk factor for CHD, independent of its saturated fat,
I cite the following references (4,5,6,7,8, 9,10).    There are numerous
animal experiments to show that added lactose increases the severity of
atherosclerosis in animal models (10,11, 12,13).  As I mentioned in my
original post, the most likely explanation for lactose's atherogenicity
is that high milk diets induce copper deficiencies (15,16) presumably
via high levels of lactose (10,14).   Copper deficiencies in turn reduce
the levels of the bodies natural antioxidants such as the Cu-Zn form of
superoxide dismutase (13,14,17).     Lowered levels of endogenous
antioxidants presumably  increase the susceptibility of LDL to oxidation
and therefore increase the risk for CHD.

                                References

4.      Segall JJ.  Dietary lactose as a possible risk factor for
ischaemic heart disease: review of epidemiology. Int J Cardiol
1994;46:197-207.
5.      Segall JJ.   Lactose.  In: Health Hazards of Milk.  DLJ Freed
(Ed.).  Bailliere Tindall, London, 1984,229-39.
6.      Segall JJ. Hypothesis: is lactose a dietary risk factor for
ischaemic heart disease. Int J Epidemiol 1980;9:271-76.
7.      Lember M et al.   Lactose absorption and milk drinking habits in
Estonians with myocardial infarction. Brit Med J 1988;296:95-96.
8.      Popham RE et al.  Variation in mortality from ischemic heart
disease in relation to alcohol and milk consumption. Med Hypotheses
1983;12:321-29.
9.      Pearce RJ.  Correlation of coronary heart disease with milk
consumption: is protein or some other factor involved? Med Hypothesis
1984;14:259-63.
10.     Strain JJ.  Milk consumption, lactose and copper in the
aetiology of ischaemic heart disease. Med Hypotheses 1988;25:99-101.
11.     Wells WW,  Anderson SC.  The increased severity of
atherosclerosis in rabbits on a lactose containing diet.  J Nutr
1959;68:541-49.
12.     Wostmann B et al.  Effect of dietary lactose at levels
comparable to human consumption on cholesterol and bile acid metabolism
of conventional and germfree rats. J Nutr 1976;106:1782-90.
13.     Carville DGM et al.  The effect of copper deficiency on blood
antioxidant enzymes in rats fed sucrose or sucrose and lactose diets.
Nutr Rep Int 1989;39:25-33.
14.     Lynch SM et al.  Effects of copper deficiency on hepatic and
cardiac antioxidant enxyme activities in lactose and sucrose fed rats.
Brit J Nutr 1989;61:345-54.
15.     Stemmer KL et al.  Copper deficiency effects on the
cardiovascular system and lipid metabolism in the rat; the role of
dietary proteins and excessive zinc. Ann Nutr Metab 1985;29:332-47.
16.     Fields M et al.  Copper deficiency in rats: the effect of type
of dietary protein. J Am Coll Nutr 1993;12:303-06.
17.     Lynch SM et al.  Effects of skimmed milk powder, whey or casein
on tissue trace element status and antioxidant enzyme activities in rats
fed control and copper deficient diets. Nut Res 1990;10:449-60.

                                        Cordially,


                                        Loren Cordain, Ph.D.
                                        Professor, Dept of ESS
                                        Colo State Univ, Ft Collins, CO
                                        80523