STRUCTURAL FATS REVISITED

by Lynn Lawson

The Winter 1987 NOHA NEWS article by Marjorie Fisher, compared structural fats with storage fats and discussed their implications for our modern diet. Reviewing the book What We Eat Today,1 by Professor Michael A. Crawford, a London (England) zoologist, and his wife Sheilagh Crawford, the article pointed out that our modern diets have become highly deficient in structural fats, which are needed inside every cell in our bodies, especially in our brains and arteries.

What exactly are these somewhat mysterious terms – structural fats and storage fats – and why do we need to know more about them? Here is a brief summary of their characteristics:

 
  • structural fats – "invisible" (to nonscientists); found inside cell structures; essential for survival and body growth and functioning; made by animals from polyunsaturated fatty acids in the soft liquid oils found in plants.
  • storage fats – "visible"; found outside cell structures, i.e., around tissues and in body cavities; used by the body for energy storage; chemically different from structural fats; obtained by humans from sugar, starch, protein, and visible animal fats.
 

Thus we have two quite different body fats – one essential to life and found in brain, liver, kidney, lung, heart, spleen, muscle, and other cells; and one found outside these organs and needed primarily by hibernating animals and by humans who eat well only during certain seasons.2 Although professional athletes can work off much of the storage fat they ingest, those leading more sedentary lives need to ingest less. Most of us do not need the storage fats nor the health problems they cause.


. . . we have two quite different body fats – one essential to life and found in brain, liver, kidney, lung, heart, spleen, muscle, and other cells; and one found outside these organs and needed primarily by hibernating animals and by humans who eat well only during certain seasons.


In looking at the relationship between food and health, it would seem that we have much to learn from the continent of Africa. Medical researchers in Africa (and elsewhere) are discovering an increasing incidence of the so-called Western diseases among native populations as their diets and lifestyles become westernized. In the preface to their pioneer work Western Diseases: their emergence and prevention,3 editors H.C. Trowell, MD, and D.P. Burkitt, MD, former professors of medicine in East Africa, define "Western diseases" as those "characteristic of modern affluent Western technological communities." In his forward to the book, John Robson, MD, notes that a shift from acute communicable diseases to chronic and degenerative diseases such as atherosclerosis, diabetes, hypertension, cancer, and obesity, long observed in the developed countries, is now occurring in the developing ones. While these researchers were aware of the adverse effects of modern technological factors such as auto accidents, industrial pollution, and new drugs, they were looking primarily at dietary changes as groups evolved from hunter-gatherers through peasant-agriculturists and migrants to westernized people.


Medical researchers in Africa (and elsewhere) are discovering an increasing incidence of the so-called Western diseases among native populations as their diets and lifestyles become westernized. . . . [they note that] a shift from acute communicable diseases to chronic and degenerative diseases such as atherosclerosis, diabetes, hypertension, cancer, and obesity, long observed in the developed countries, is now occurring in the developing ones.


Likewise, the Crawfords based many of their conclusions about structural fats on their extensive research on the eating habits of wildlife and humans in Africa, which they then compared with those of modern civilization. Modern food production, they observed, affects the structural/storage fat ratio in two major ways:

 
  • Food processors prefer to change the delicate, easily oxidized, unstable polyunsaturated fatty acids into hard, solid, stable saturated fatty acids so that they won’t spoil.
  • Meat producers, for economic reasons, prefer to grow animals in feedlots rather than on the range, where they would get plenty of exercise and eat a greater variety of plant matter, thus increasing their structural fats and decreasing their obesity from storage fats. Consequently, we find ourselves eating meat from obese animals.
 

The Crawfords speculate that the loss of structural fat in domesticated animals is related to the 30 percent loss in brain size of domesticated animals throughout the process of domestication. In fact, "paleontologists use the [30 percent loss of brain capacity] to identify whether of not remains found in caves are from domestic or wild animals."4

"No, this is not what Dr. Rinkel meant by a Rotary Diversified Diet."

 

In this context, the Winter 1987 quote from the Crawfords’ book bears repeating:


"Recent ecological and technical manipulation has consistently and unwittingly fiddled with the building materials for the human brain. In our view, if you distort and depress the availability of the lipid building blocks you are asking for reduction in brain size and capacity."


The dangers can now be foreseen and are quite simple. We now know for a fact that certain unstable lipids or fats are found in the human brain, in the arteries, and to a lesser extent, in every cell in the body. We also know that these lipids are present in the food chain but are being lost. Recent ecological and technical manipulation has consistently and unwittingly fiddled with the building materials for the human brain. In our view, if you distort and depress the availability of the lipid building blocks you are asking for reduction in brain size and capacity. Similarly, degenerative effects on longevity and performance, [and on] the nervous and vascular systems and reproductive systems could be predicted. . . . There is no use in having large unintelligent people who survive only for a short time.5


Elephants, which in their native forest habitats have a . . . fibrous oil-rich diet, have been observed to degenerate when confined to the grassland areas of game parks. Two medical researchers "independently produced the startling conclusion that one of the major obvious pathological changes seen in grassland elephants was gross arterial degeneration with excessive calcification not dissimilar from that seen in humans."


What can we learn from this alarming prospect and the evidence that led up to it? A significant insight may come from the Crawfords’ studies of certain African animals, such as the giraffe – one of their more vivid descriptions. The giraffe, a herbivore with twice our blood pressure, requires a superb cardiovascular system, including at least eight feet of carotid artery in its neck. As might be expected, about 99 percent of its food comes from trees and bushes, rather than grass. Giraffes range widely, eating from a wide variety of trees. According to the Crawfords, "A remarkably long tongue is placed halfway up a branch and one sweep pulls off all the leaves, fruits, flowers, and buds, [also] twigs, and . . . thorns."5 Elephants, which in their native forest habitats have a similar fibrous oil-rich diet, have been observed to degenerate when confined to the grassland areas of game parks. Two medical researchers "independently produced the startling conclusion that one of the major obvious pathological changes seen in grassland elephants was gross arterial degeneration with excessive calcification not dissimilar from that seen in humans."6 Also, "studies on the chemistry of the tissues of giraffe and elephant revealed that the oil-rich nature of their food structure was reflected in their tissue structural fats by comparison with the grass-eating herbivores. Furthermore, tissue degeneration in grassland elephants was associated with loss of structural fats."7


fresh fruit, raw nuts and seeds, wild game, and fresh fish [are] described as nutrient-dense superior foods. Fresh fish are known to be a good source of the unsaturated fatty acids, particularly the omega-3 fatty acids so necessary for our bodies but so undersupplied in many modern processed foods.


From these observations, one is inescapably drawn to NOHA’s recently revised "Bull’s Eye." There one sees in the center ring, among other foods, fresh fruit, raw nuts and seeds, wild game, and fresh fish – described as nutrient-dense superior foods. Fresh fish are known to be a good source of the unsaturated fatty acids, particularly the omega-3 fatty acids so necessary for our bodies but so undersupplied in many modern processed foods. Once again, one is reminded of the maxim "Eat as close to nature as possible," nature in this case implying the same fibrous, oil-rich foods of the African wild game – and even the wild game itself. Also, the Crawfords’ research is further evidence of the need to avoid processed foods, in which the manipulation of ingredients has resulted in the loss of essential oils and structural fats. For example, in their laboratories the Crawfords found that "homemade chicken soup contained ten times the amount of structural fats as [the] chicken soup from a packet or tin."8 Was Grandma on the right track after all?9

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1Crawford, M.A., and S. Crawford, What We Eat Today, London: Neville Spearman, 1972.
2Ibid., pp. 29-30.
3Trowell, H.C. and D.P. Burkitt, eds., Western Diseases: their emergence and prevention, Cambridge: Harvard University Press, 1981.
4Letter from Professor Crawford to Marjorie Fisher, October 22, 1986.
5Crawford, op.cit. p. 161.
6Ibid., p. 65.
7Ibid.
8Ibid., p. 45.
9This grandmother-writer enjoys her breakfasts consisting almost entirely of organically grown nuts and fruit, both dried and fresh, plus an herb tea. When put on a four-day rotation diet avoiding milk and all grains several years ago, she found breakfast the hardest meal to plan. Now it is the easiest: nuts and fruit require no preparation, are easy to buy, permit great variety, travel well, store indefinitely in the freezer, keep her going until a late lunch, and taste delicious. Though an urban carnivorous biped, she thinks she may be faring almost as well nutritionally as the African herbivores.

Article from NOHA NEWS, Vol. XIII, No. 4, Fall 1988, pages 1-3