# Nutrition, Protein Metabolism, and Human Development

## GA 354 — 2 August 1924, Dornach

### Lecture VII

*Rudolf Steiner*: Today I would like to add a little more in answer to Herr Burle's question last Thursday. You remember that I spoke of the four substances necessary to human nutrition: minerals, carbohydrates, which are to be found in potatoes, but especially in our field grains and legumes, then fats, and protein. I pointed out how different our nutrition is with regard to protein as compared, for instance, to salt. A man takes salt into his body and it travels all the way to his head, in such a way that the salt remains salt. It is really not changed except that it is dissolved. It keeps its forces as salt all the way to the human head. In contrast to this, protein—the protein in ordinary hens' eggs, for instance, but also the protein from plants—this protein is at once broken down in the human body, while it is still in the stomach and intestines; it does not remain protein. The human being possesses forces by which he is able to break down this protein. He also has the forces to build something up again, to make his own protein. He would not be able to do this if he had not already broken down other protein.

Now think how it is, gentlemen, with this protein. Imagine that you have become an exceptionally clever person, so clever that you are confident you can make a watch. But you've never seen a watch except from the outside, so you cannot right off make a watch. But if you take a chance and you take some watch to pieces, take it all apart and lay out the single pieces in such a way that you observe just how the parts relate to one another, then you know how you are going to put them all together again. That's what the human body does with protein. It must take in protein and take it all apart.

Protein consists of carbon, nitrogen, oxygen, hydrogen and sulphur. Those are its most important components. And now the protein is completely separated into its parts, so that when it all reaches the intestines, man does not have protein in him, but he has carbon, nitrogen, oxygen, hydrogen, and sulphur. You see how it is?—now the man has the protein all laid out in its parts as you had the watch all laid out on the table. So now you will say, Sure! when I took that watch apart, I observed it very carefully, and now I can make watches. Likewise I only need to eat protein once; after that, I can make it myself. But it doesn't happen that way, gentlemen. A human being has his memory as a complete human entity; his body by itself does not have the kind of memory that can take note of something, it uses its “memory” forces just for building itself up. So one must always be eating new protein in order to be able to make a protein.

The fact is, the human being is involved in a very, very complicated activity when he manufactures his own protein. First he divides the protein he has eaten into its separate parts and puts the carbon from it into his body everywhere. Now you already know that we inhale oxygen from the air and that this oxygen combines with the carbon we have in us from proteins and other food elements. And we exhale carbon in carbon dioxide, keeping a part of it back. So now we have that carbon and oxygen together in our body. We do not retain and use the oxygen that was in the protein; we use the oxygen we have inhaled to combine with the carbon. Thus we do not make our own protein as the materialists describe it: namely, that we eat a great many eggs which then are deposited throughout our body so that eggs we have eaten are spread over our whole body. That is not true.

Actually, we are saved by the organization of our body so that when we eat eggs, we don't all turn into crazy hens! It's a fact. We don't become crazy hens because we break the protein down in our intestines and instead of using the oxygen that was in the protein, we use oxygen coming out of the air. Also, as we breathe oxygen in we breathe nitrogen in too; nitrogen is always in the air. Again, we don't use the nitrogen that comes to us in the hens' eggs; we use the nitrogen we breathe in from the air. And the hydrogen we've eaten in eggs, we don't use that either, not at all. We use the hydrogen we take in through our nose and our ears, through all our senses; that's the hydrogen we use to make our protein. Sulphur too—we receive that continually from the air. Hydrogen and sulphur we get from the air. From the protein we eat, we keep and use only the carbon. The other substances, we take from the air. So you see how it is with protein.

There is a similar situation with fat. We make our own protein, using only the carbon from the external protein. And we also make our own fat. For the fats too, we use very little nitrogen from our food. So you see, we produce our own protein and fat. Only what we consume in potatoes, legumes, and grains goes over into our body. In fact, even these things do not go fully into our body, but only to the lower part of our head. The minerals we consume go up into the entire head; from them we have what we need to build up our bones.

Therefore you see, gentlemen, we must take care to bring healthy plant protein into our body. Healthy plant protein! That is what our body needs in large quantity. When we take in protein from eggs, our body can be rather lazy; it can easily break the protein down, because that protein is easily broken down. But plant protein, which we get from fruit—it is chiefly in that part of the plant, as I told you on Thursday—that is especially valuable to us. If a person wants to keep himself healthy, it is really necessary to include fruit in his diet. Cooked or raw, but fruit he must have. If he neglects to eat fruit, he will gradually condemn his body to a very sluggish digestion.

You can see that it is also a question of giving proper nourishment to the plants themselves. And that means, we must realize that plants are living things; they are not minerals, they are something alive. A plant comes to us out of the seed we put in the ground. The plant cannot flourish unless the soil itself is to some degree alive. And how do we make the soil alive? By manuring it properly. Yes, proper manuring is what will give us really good plant protein.

We must remember that for long, long ages men have known that the right manure is what comes out of the horses' stalls, out of the cow barn and so on; the right manure is what comes off the farm itself. In recent times when everything has become materialistic, people have been saying: Look here! we can do it much more easily by finding out what substances are in the manure and then taking them out of the mineral kingdom: mineral fertilizer!

And you can see, gentlemen, when one uses mineral fertilizer, it is as if one just put minerals into the ground; then only the root becomes strong. Then we get from the plants the substance that helps to build up our bones. But we don't get a proper protein from the plants. And the plants, our field grains have suffered from the lack of protein for a long time. And the lack will become greater and greater unless people return to proper manuring.

There have already been agricultural conferences in which the farmers have said: Yes, the fruit gets worse and worse! And it is true. But naturally the farmers haven't known the reason. Every older person knows that when he was a young fellow, everything that came out of the fields was really better. It's no use thinking that one can make fertilizer simply by combining substances that are present in cow manure. One must see clearly that cow manure does not come out of a chemist's laboratory but out of a laboratory that is far more scientific—it comes from the far, far more scientific laboratory inside the cow. And for this reason cow manure is the stuff that not only makes the roots of plants strong, but that works up powerfully into the fruits and produces good, proper protein in the plants which makes man vigorous.

If there is to be nothing but the mineral fertilizer that has now become so popular, or just nitrogen from the air—well, gentlemen, your children, more particularly, your grandchildren will have very pale faces. You will no longer see a difference between their faces and their white hands. Human beings have a lively, healthy color when the farmlands are properly manured.

So you see, when one speaks of nutrition one has to consider how the foodstuffs are being obtained. It is tremendously important. You can see from various circumstances that the human body itself craves what it needs. Here's just one example: people who are in jail for years at a stretch, usually get food that contains very little fat, so they develop an enormous craving for fat; and when sometimes a drop of wax falls on the floor from the candle that the guard carries into a cell, the prisoner jumps down at once to lick up the fat. The human body feels the lack so strongly if it is missing some necessary substance. We don't notice this if we eat properly and regularly from day to day; then it never happens that our body is missing some essential element. But if something is lacking in the diet steadily for weeks, then the body becomes exceedingly hungry. That is also something that must be carefully noticed.

I have already pointed out that many other things are connected with fertilizing. For instance, our European forefathers in the twelfth and thirteenth centuries, or still earlier, were different from ourselves in many ways. One doesn't usually pay any attention to that fact. Among other things, they had no potatoes! Potatoes were not introduced until later. The potato diet has exercised a strong influence. When grains are eaten, the heart and lungs become particularly strong. Grains strengthen heart and lungs. A man then develops a healthy chest and he is in fine health. He is not so keen on thinking as on breathing, perhaps; but he can endure very much when he has good breathing. And let me say right here: don't think that someone has strong lungs if he's always opening the window and crying, “Let's get some fresh air in here!” No! a person has strong lungs if he is so conditioned that he can endure any kind of air. The toughened-up person is not the one who can't bear anything but the one who can!

In these days there is much talk about being hardy. Think how the children are “hardened”! Nowadays (in wealthy homes, of course, but then other people quickly follow suit) the children are dressed—well, when we were children, we wore long breeches and were well covered—at the most, we went barefoot-now, the clothes only go down to the knee or are still shorter. If parents knew that this is the best preparation for later attacks of appendicitis, they would be more thoughtful. But fashion is a tyrant!—no thought is given to the matter, and the children are dressed so that their little dresses only reach to the knee, or less. Someday they will only reach to the stomach—that will be the fashion! Fashion has a strong influence.

But what is really at stake? People pay no attention to it. It is this: A human being is constituted throughout his organism so that he is truly capable of doing inner work on all the food he consumes. And in this connection it is especially important to know that a man becomes strong when he works properly on the foods he eats. Children are not made stronger by the treatment I have just mentioned. They are so “hardened” that later in their life—just watch them!—when they have to cross an empty square with the hot sun beating down on them, they drip with perspiration and they can't make it. Someone has not become toughened up when he is not able to stand anything; the person who can endure all possible hardships is the one who has been toughened up. So, in earlier days people were not toughened up; yet they had healthy lungs, healthy hearts, and so on.

And then came the potato diet! The potato takes little care of lung and heart. It reaches the head, but only, as I said, the lower head, not the upper head. It does go into the lower head, where one thinks and exercises critical faculties. Therefore, you can see, in earlier times there were fewer journalists. There was no printing industry yet. Think of the amount of thought expended daily in this world in our time, just to bring the newspapers out! All that thinking, it is much too much, it is not at all necessary-and we have to thank the potato diet for that! Because a person who eats potatoes is constantly stimulated to think. He can't do anything but think. That's why his lungs and his heart become weak. Tuberculosis, lung tuberculosis, did not become widespread until the potato diet was introduced. And the weakest human beings are those living in regions where almost nothing else is grown but potatoes, where the people live on potatoes.

It is spiritual science that is able to know these material facts. (I have said this often.) Materialistic science knows nothing about nutrition; it has no idea what is healthy food for humanity. That is precisely the characteristic of materialism, that it thinks and thinks and thinks—and knows nothing. The truth is finally this: that if one really wants to participate in life, above all one has to know something! Those are the things I wanted to say about nutrition.

And now perhaps you may still like to ask some individual questions?

*Question*: Dr. Steiner, in your last talk you mentioned arteriosclerosis. It is generally thought that this illness comes from eating a great deal of meat and eggs and the like. I know someone in whom the illness began when he was fifty; he had become quite stiff by the time he was seventy. But now he is eighty-five or eighty-six, and he is much more active than he was in his fifties and sixties. Has the arteriosclerosis receded? Is that possible? Or is there some other reason? Perhaps I should mention that this person has never smoked and has drunk very little alcohol; he has lived a really decent life. But in his earlier years he did eat rather a lot of meat. At seventy he could do very little work, but now at eighty-five he is continually active.

*Dr. Steiner*: So—I understand you to say that this person became afflicted with arteriosclerosis when he was fifty, that he became stiff and could do very little work. You did not say whether his memory deteriorated; perhaps you did not notice. His condition continued into his seventies; then he became active again, and he is still living. Does he still have any symptom of his earlier arteriosclerosis or is he completely mobile and active?

*Questioner*: Today he is completely active and more mobile than when he was sixty-five or seventy. He is my father.

*Dr. Steiner*: Well, first of all we should establish the exact nature of his earlier arteriosclerosis. Usually arteriosclerosis takes hold of a person in such a way that his arteries in general become sclerotic. Now if a man's arteries in general are sclerotic, he naturally becomes unable to control his body with his soul and spirit, and the body becomes rigid. Now it can also happen that someone has arteriosclerosis but not in his whole body; the disease, for instance, could have spared his brain. Then the following is the case. You see, I am somewhat acquainted with your own condition of health. I don't know your father, but perhaps we can discover something about your father's health from your own. For instance, you suffer somewhat, or have suffered (I hope it will be completely cured), from hay fever. That means that you carry in you something that the body can develop only if there is no tendency to arteriosclerosis in the head, but only outside the head. No one who is predisposed to arteriosclerosis in his entire body can possibly suffer an attack of hay fever. For hay fever is the exact opposite of arteriosclerosis. Now you suffer from hay fever. That shows that your hay fever—of course it is not pleasant to have hay fever, it's much better to have it cured: but we are talking of the tendency to have it—your hay fever is a kind of safety valve against arteriosclerosis.

But everyone gets arteriosclerosis to a small degree. One can't grow old without having it. If one gets it in the entire body, that's different: then one can't help oneself, one becomes rigid through one's whole body. But if one gets arteriosclerosis in the head and not in the rest of the body, then—well, if one is growing old properly, the etheric body is growing stronger and stronger (I've spoken of this before), and it no longer has such great need of the brain, and so the brain can now become old and stiff. The etheric body can control this slight sclerotic condition—which in earlier years made one old and stiff altogether; now the etheric body can control it very cleverly so that it is no longer so severe.

Your father, for example, does not need to have had hay fever himself, he can just have had the tendency to it. And you see, just this tendency to it has been of benefit to him. One can even say—it may seem a little far-fetched, but a person who has a tendency to hay fever can even say, Thank God I have this tendency! The hay fever isn't bothering me now, and it gives me permanently the predisposition to a softening of the vessels. Even if the hay fever doesn't come out, it is protecting him from arteriosclerosis. And if he has a son, the son can have the hay fever externally. A son can suffer externally from some disease that in the father was pushed inward.

Indeed, that is one of the secrets of heredity: that many things become diseases in the descendants which in the forefathers were aspects of health. Diseases are classified as arteriosclerosis, tuberculosis, cirrhosis, dyspepsia, and so forth. This can be written up very attractively in a book; one can describe just how these illnesses progress. But one hasn't obtained much from it, for the simple reason that arteriosclerosis, for instance, is different in every single person. No two persons have arteriosclerosis alike; everyone becomes afflicted in a different way. That is really so, gentlemen. And it shouldn't surprise anyone.

There were two professors[^1] at Berlin University. One was seventy years old, the other ninety-two. The younger one was quite well-known; he had written many books. But he was a man who lived with his philosophy entirely within materialism; he only had thoughts that were stuck deep in materialism. Now such thoughts also contribute to arteriosclerosis. And he got arteriosclerosis. When he reached seventy, he was obliged to retire. The colleague who was over ninety was not a materialist; he had stayed a child through most of his life, and was still teaching with tremendous liveliness. He said, “Yes, that colleague of mine, that young boy! I don't understand him. I don't want to retire yet, I still feel so young.” The other one, the “boy,” was disrobed, could no longer teach. Of course the ninety-two-year-old had also become sclerotic with his years, his arteries were completely sclerotic, but because of his mobility of soul he could still do something with those arteries. The other man had no such possibility.

And now something more in answer to Herr Burle's question about carrots. Herr Burle said, “The human body craves instinctively what it needs. Children often take a carrot up in their hands. Children, grownups too, are sometimes forced to eat food that is not good for them. I think this is a mistake when someone has a loathing for some food. I have a boy who won't eat potatoes.”

Gentlemen, you need only think of this one thing: if animals did not have an instinct for what was good for them, and what was bad for them, they would all long since have perished. For animals in a pasture come upon poisonous plants too—all of them—and if they did not know instinctively that they could not eat poisonous plants, they would certainly eat them. But they always pass them by.

But there is something more. Animals choose with care what is good for them. Have you sometimes fattened geese, crammed them with food? Do you think the geese would ever do that themselves? It is only humans who force the geese to eat so much. With pigs it is different; but how thin do you think our pigs might be if we did not encourage them to eat so much? In any case, with pigs it is a little different. They have acquired their characteristics through inheritance; their ancestors had to become accustomed to all the foods that produce fat. These things were taken up in their food in earlier times. But the primeval pigs had to be forced to eat it! No animal ever eats of its own accord what is not right for it.

But now, gentlemen, what has materialism brought about? It no longer believes in such an instinct.

I had a friend in my youth with whom I ate meals very often. We were fairly sensible about our food and would order what we were in the habit of thinking was good for us. Later, as it happens in life, we lost track of each other, and after some years I came to the city where he was living, and was invited to have dinner with him. And what did I see? Scales beside his plate! I said, “What are you doing with those scales?” I knew, of course, but I wanted to hear what he would say. He said, “I weigh the meat they bring me, to eat the right amount—the salad too.” There he was, weighing everything he should put on his plate, because science told him to. And what had happened to him? He had weaned himself completely from a healthy instinct for what he should eat and finally no longer knew! And you remember?—it used to be in the book: “a person needs from one hundred and twenty to one hundred and fifty grams of protein”; that, he had conscientiously weighed out. Today the proper amount is estimated to be fifty grams, so his amount was incorrect.

Of course, gentlemen, when a person has diabetes, that is obviously a different situation. The sugar illness, diabetes, shows that a person has lost his instinct for nutrition.

There you have the gist of the matter. If a child has a tendency to worms, even the slightest tendency, he will do everything possible to prevent them. You'll be astonished sometimes to see such a child hunting for a garden where there are carrots growing, and then you'll find him there eating carrots. And if the garden is far off, that doesn't matter, the child trudges off to it anyway and finds the carrots-because a child who has a tendency to worms longs for carrots.

And so, gentlemen, the most useful thing you can possibly do is this: observe a child when he is weaned, when he no longer has milk, observe what he begins to like to eat and not like to eat. The moment a child begins to take external nourishment, one can learn from him what one should give him. The moment one begins to urge him to eat what one thinks he should eat, at that moment his instinct is spoilt. One should give him the things for which he shows an instinctive liking. Naturally, if a fondness for something threatens to go too far, one has to dam it up—but then one must carefully observe what it is that one is damming up.

For instance, perhaps in your own opinion you are giving a child every nice thing, and yet the moment that child comes to the table he cannot help jumping up on his chair and leaning over the table to sneak a lump of sugar! That's something that must be regarded in the right way. For a child who jumps up on his chair to sneak a lump of sugar obviously has something the matter with his liver. Just the simple fact that he must sneak a bit of sugar, is a sign that his liver is not in order. Only those children sneak sugar who have something wrong with their livers—it is then actually cured by the sugar. The others are not interested in sugar; they ignore it. Naturally, such a performance can't be allowed to become a habit; but one must have understanding for it. And one can understand it in two directions.

You see, if a child is watching all the time and thinking, when will Father or Mother not be looking, so that I can take that sugar: then later he will sneak other things. If you satisfy the child, if you give him what he needs, then he doesn't become a thief. It is of great importance from a moral point of view whether one observes such things or not. It is very important, gentlemen.

And so the question that was asked just now must be answered in this way: One should observe carefully what a child likes and what he loathes, and not force him to eat what he does not like. If it happens, for instance, as it does with very many children, that he doesn't want to eat meat, then the fact is that the child gets intestinal toxins from meat and wants to avoid them. His instinct is right. Any child who can sit at a table where everyone else is eating meat and can refuse it has certainly the tendency to develop intestinal toxins from meat. These things must be considered.

You can see that science must become more refined. Science must become much more refined! Today it is far too crude. With those scales, with everything that is carried on in the laboratories, one can't really pursue pure science.

With nutrition, which is the thing particularly interesting us at this moment, it is really so, that one must acquire a proper understanding for the way it relates to the spirit. When people inquire in that direction, I often offer two examples. Think, gentlemen, of a journalist: how he has to *think* so much—and so much of it isn't even necessary. The man must think a great deal, he must think so many logical thoughts; it is almost impossible for any human being to have so many logical thoughts. And so you find that the journalist—or any other person who writes for a profession—loves coffee, quite instinctively. He sits in the coffee shop and drinks one cup after another, and gnaws at his pen so that something will come out that he can write down. Gnawing at his pen doesn't help him, but the coffee does, so that one thought comes out of another, one thought joins on to another.

And then look at the diplomats. If one thought joins on to another, if one thought comes out of another, that's bad for them! When diplomats are logical, they're boring. They must be entertaining. In society people don't like to be wearied by logical reasoning—“in the first place – secondly—thirdly”—and if the first and second were not there, the third and fourth would, of course, not have to be thought of! A Journalist can't deal with anything but finance in a finance article. But if you're a diplomat you can be talking about night clubs at the same time that you're talking about the economy of country X, then you can comment on the cream-puffs of Lady So-and-So, then you can jump to the rich soil of the colonies, after that, where the best horses are being bred, and so on. With a diplomat one thought must leap over into another. So anyone who is obliged to be a charming conversationalist follows his instinct and drinks lots of tea.

Tea scatters thoughts; it lets one jump into them. Coffee brings one thought next to another. If you must leap from one thought to another, then you must drink tea. And one even calls them “diplomat teas”!—while there sits the journalist in the coffee shop, drinking one cup of coffee after another. You can see what an influence a particular food or drink can have on our whole thinking process. It is so, of course, not just with those two beverages, coffee and tea; one might say, those are extreme examples. But precisely from those examples I think you can see that one must consider these things seriously. It is very important, gentlemen.

So, we'll meet again next Wednesday at nine o'clock.

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[^1]: The philosopher Karl Ludwig Michelet, 1801–1893, and the theologian and philosopher Eduard Zeller, 1814–1908. See Rudolf Steiner, *Study of Man: General Education Course*, Stuttgart, Aug. – Sept. 1919. Anthroposophic Press, New York. See also *The Younger Generation: Educational and Spiritual impulses for Life in the Twentieth Century*, Stuttgart, October 1922. Anthroposophic Press, New York.