Esoteric Nutritional Information but probably of interest to the public

 

        Esoteric means unusual, scarcely known except to experts.

1)      Wheat is especially known for containing ample tryptophane, an essential amino acid that can be converted to niacin (vitamin B3) in a pinch.  Corn is deficient in both tryptophane and niacin; hence, diets high in corn are the major cause of pellagra, the disease caused by niacin deficiency.

2)      Βeta carotene, the pigment that makes carrots orange, is a precursor of vitamin A.  Pure vitamin A is toxic in even a moderate excess, but the body in its wisdom fails to convert carotene (and other vitamin A precursors) to active vitamin A in the presence of adequate amounts of the active form.  We cannot be sure that our bodies are “wise” enough not to convert some of an outlandish excess of vitamin A precursors.  In other words, avoid beta carotene and its ilk in quantities greater than present in any likely diet.

3)      Vitamin B12 is present only in foods of animal origin and nutritional yeast.  Only tiny amounts are needed for health so that very small quantities of foods of animal origin protect against deficiency.  However, vitamin B12 is not absorbed in the absence of a special factor secreted by the stomach associated with its acid secretion.  Only people, especially the elderly, with inadequate stomach acid and total vegetarians need supplements.  In pernicious anemia the vitamin B12 is best injected because the total absence of the stomach factor prevents absorption.

4)      The optimum supplemental daily dose of folic acid for young women to prevent congenital birth defects in their offspring is 0.4 mg daily.  This same dose of folic acid approximates the additional folic acid in the diet of paleolithic mankind prior to settled agriculture.  Settled agriculture permitted storing grain to prevent famines.  However, cereal grains are deficient in folic acid compared to the greater variety of foods such as roots and nuts previously eaten instead of the cereals we eat.  The chief benefit of eating lettuce is for folic acid and roughage.  (A theologian might mention the original sin of agriculture.)

5)      Proteins are composed of chains of amino acids.  There are about twenty different amino acids, but only about twelve of them are essential in that they cannot be made from other components of the diet.  (One nonessential amino acid is essential for cats but not for us.)  Egg protein and the protein of whey have a perfect mix of the essential ones.  However, mixtures of foods with otherwise deficient proportions of their amino acids can correct each other’s deficiencies if eaten together.  Rice and beans are a very effective combination.  This information is scarcely pertinent except for vegetarians.  Rice for lunch and beans for supper cannot supplement each other; but eat a little meat or dairy products here and there, and it doesn’t matter.

6)      Many chemicals such as cholesterol and lecithin can be made in our bodies in any amount needed.  Excess cholesterol may be harmful as most of us know, but lecithin is nontoxic even in very large doses.  Bottom line: lecithin supplements are a total waste of money.  The same logic applies to glyconutrients.

7)      The first 800-1000 calories of carefully selected foods can contain all essential nutrients except for the calories required for various levels of physical activity.  A related fact: the extra calories required for vigorous exercise can all be junk without causing deficiency.  A partial exception to this statement is that high carbohydrate diets require more thiamin.  This is the reason that white flour is fortified with thiamin, vitamin B1.  Whole wheat contains adequate amounts of thiamin to go with its calories.  Incidentally, white flour was originally developed to prolong the shelf life of milled wheat, not to permit donuts and angel food cake.  Conclusion: varmints prefer real food.

8)      Physical exercise is penance in advance for the sin of overeating.  Our appetites are designed to prevent starvation, so increasing exertion turns on the appetite to prevent starvation.  To a varying extent we have all been selected to overeat when food is plentiful to enhance survival of repeated famines.  Settled agriculture with its stored food bred some of this overeating tendency out of us because of fewer famines especially among upper social classes.  Stored food to avoid famines has existed longer in Europe than elsewhere.  Social stratification in Europe discouraged marriage outside of one’s social class, and upper class Europeans were least likely to emigrate. Criminals were most likely to emigrate because they were sent to the colonies especially Australia to serve their sentences and not given passage home (conscription of settlers). North American immigrants tended to be middle class.  This explains why diabetes is more prevalent in European immigrants to North America than in those who stayed home and, of these three groups, most prevalent in Australians.  Australian aborigines and native people throughout the world have not been spared multiple famines until very modern times.  The higher incidence of obesity and diabetes in black people in North America compared to Caucasians fits with this even though few of them have pure African inheritance.

 

Because of increasingly sedentary life styles, public health authorities are bracing themselves for greatly increasing incidence of diabetes especially in the underdeveloped world as affluence and inactivity both increase there.  Bottom line: live closer to work and walk or bicycle for local transportation.  My inheritance and lifelong habits tend to confirm this.  I figured this out to some extent even before attending medical school because my parents were both overweight all of their adult lives.  (I have a carefully preserved suit from 70 years ago to wear occasionally as an ego trip.)

John A. Frantz, MD

January 7, 2011   

 

What could be Less Toxic than Water?

Vitamin C (ascorbic acid) is one of the least toxic substances.  Obviously water is less toxic in terms of the weight of it that is required to be harmful when ingested.  However if the criterion for the least toxic is the multiple of the desirable dose that is still nontoxic, vitamin C is much less toxic than water.  Forty mg. daily is required for health.  Four thousand mg.is still harmless---100 times 40.   

Some substantial fraction of a gallon of water per day is healthy.  Five to ten times that amount taken orally in a short time might be fatal because of exceeding the kidney’s ability to excrete it and the resulting dilution and excess volume of the blood.   Compare with 100 times too much vitamin C being harmless. 

It is interesting that as toxic doses of vitamin C are approached, it starts to be destroyed in the body instead of merely excreted.  A major portion of the destroyed vitamin C is converted to oxalic acid.  Fatal doses of oxalic acid could easily be consumed based on this mechanism.  Don’t worry too much---it hasn’t happened yet.  Mild chronic oxalate poisoning would lead almost inevitably to Kidney stones.  

A possibility, short of fatality, that also has not been reported: could induction of the destruction of vitamin C by enormous doses result in temporary deficiency if the enormous dose were abruptly reduced to 40 mg. daily?  It could well be that the destruction could not be so immediately curtailed.  Food for thought

Bottom line: this is a logical rebuttal to the error in thinking, “If a little is good, more is better.”  

PS Google told me that the dose of vitamin C that kills 50% of rats is 11,900,000,000 nanograms.per kilogram (11.9 grams per kg).  14,000,000,000 ng (14 grams) has been given to adult humans in a single dose.  This is 200 mg. per kg.  A discussant said that twice that amount would probably not have been fatal.  The doses of toxic materials on Wikipedia were all in nonograms presumably to emphasize the unique toxicity of Clostridium botulinum toxin, 1ng/kg (0.000,000,001 gm/kg).

      John A. Frantz, MD  

      January 13, 2010