[Of all the excellent magazines published by major research universities to call attention to faculty research, Engineering & Science, published by California Institute of Technology is outstanding for the range of its interests. While dutifully recognizing faculty accomplishments, from time to time it also illuminates some link between science and other human concerns. Recent examples were a detailed account of Richard Feynmann's adventures in Washington Wonderland, a brilliant essay by playwright Tom Stoppard on science and the stage, and the exercise below-in which one of Caltech's designated Distinguished Alumni delivers an exhilarating rejection of nearly every solemn instruction that physicians have been giving to their middle-aged patients.]
... One night in 1970, a woman named Judith Taylor came into a Toronto hospital with abdominal pains. They opened her up and found she had gangrene throughout her entire intestinal tract; the surgeon had to remove the whole thing. A young Indian physician, Dr. K. N. Jeejeebhoy, who was present that night, came up with an idea, and from then on, Judith Taylor and now tens of thousands of others of all ages have been sustained on an intravenous solution called total parenteral nutrition, or TPN, containing 44 chemicals in six major categories. All TPN bags are the same, in terms of having the same 44 chemicals, but the amounts are a function of the age, sex, and lifestyle of the individual who requires those nutrients.
First and foremost of the major categories is water. We are creatures in a biological world of water. I don't want to go into all the details of it as a solvent, as an ionizing material, as a heat-control mechanism, a chemical reactant-all sorts of beautiful things. You have to have water, eight glasses or its equivalent per day.
In most total parenteral nutrition bags, 55 percent of the calories come from fats. And what do the "croakers" tell you, the guys who wear the white coats with stethoscopes and little names over the pocket, the guys with the beards, the Dr. Koops? They tell you 30 percent, don't they? So how come all these people on TPN haven't dropped dead? The French get 45 percent of their calories from fat, and they have half the rate of coronary heart disease and half the rate of obesity that we have. But fat is bad, you say. We know that, don't we? There are guys running around up in San Francisco with bean sprouts in their ears telling us we have to get down to 10 percent.
Oh, you say, with the French it's the wine. No, it isn't, my friends; it's the total calories. You want to know what the curse of fat is?-Fat makes food taste good. Nobody has ever asked for seconds on total parenteral nutrition. Fat makes food taste good, and so we eat more food. And when we eat more food, we eat more calories. Very simple. You don't have to have a PhD from Caltech. A simple bachelor's degree will do.
What else in the bag gives you calories? Glucose. My God, that's a sugar!-Sugar rots your teeth; sugar causes hyperkinesis in little children; sugar causes homicidal tendencies in ex-city councilmen from San Francisco. Did you know that sugars-glucose (or sucrose if you, unlike people on TPN, have a gut to digest it)-or complex carbohydrates, are absolutely required for life? There is no such thing as an empty calorie. Sugar is a precursor for pentose, and for oxaloacetic acid, which runs the Krebs cycle, the series of chemical reactions that oxidizes food to provide energy and release carbon dioxide and water as waste products. Diabetes is a fatal disease, in which the cells don't get adequate glucose. So don't talk to me about empty calories.
Next on the list come minerals: sodium, potassium, calcium, magnesium, sulfate, chloride, phosphate. Did I say sodium chloride? But we know that sodium chloride is bad for us, don't we? It causes hypertension. For everybody? No, only if your kidneys are rotten. If you've got lousy kidneys then the salt is very toxic. Fifteen percent of the population has lousy kidneys. So tell me, what the hell are the other 85 percent doing running around looking for pretzels without salt? Bad kidneys are caused by bad genes, obesity, stress, smoking, or excessive amounts of alcohol. But salt doesn't cause bad kidneys; salt causes hypertension if you have bad kidneys. If you've got a problem, deal with your problem.
Calcium is another mineral in the bag. I've published a lot of experiments on calcium; I'm a calcium guru. We were the first ones to show that bone loss in postmenopausal women can be reversed with 1,000 mg of calcium plus one RDA (recommended dietary allowance) of zinc, manganese and copper. A thousand milligrams of calcium is a quart of milk. Even better is 1,500 mg-a quart and a half of milk, a quart of yogurt, or a quarter of a pound of cheese. But, you say, you eat a lot of dark-green, leafy vegetables. Do you eat four and a half pounds a day? Most women in America get 500 mg of calcium a day on average-half of what they need. Is it any wonder that 30 percent of postmenopausal American women have osteoporosis?
We need essential amino acids-I won't dwell on them. There are eight of them. We get them from the protein in our diets. Don't let people kid you that vegetarianism is God's own way. Maybe it is Her way, but if it is, you'd better be sure that you balance the gains and the legumes, because you're not going to get those eight essential aminos if you don't. Most people who are on strict vegetarian diets never get the amount of essential amino acids for proper growth.
Then come the 13 vitamins-4 fat soluble, 9 water soluble. We know the structure and function of all of them. Does it matter whether they're synthetic or natural? No. Are there any data that say that megadosing does anything? No. Here I'm saying it in Linus's own palace. I love Linus, but he was wrong about vitamin C. There are no data that support him on the claims that megadosing of any vitamin prevents or cures disease, antioxidants notwithstanding. ... If you're having deficiency problems, that's something else. Or if you're pregnant. Birth defects and malnutrition among the poor are a big problem in this country. Too many young women give birth to premature babies because they don't have the vitamins and the minerals and the trace elements. Folic acid deficiency is directly linked to spina bifida, and any vitamin deficiency gives rise to malformations. It's damned tough to get 100 percent of the U.S. RDA if you're trying to do it in food off the shelf. Should you try to do it in food? Of course. But it makes no difference if you get what you need from vitamin supplements or fortified foods. It's in the bag. That's all that counts.
Last come my favorites: the trace elements, all 11 of them-including the iron, the copper, the zinc, the manganese, the fluoride, the iodine, the selenium. I got tenure on these elements. The biggest nutritional-deficiency disease in America is iron-deficiency anemia, and with it goes copper deficiency, and frequently manganese and zinc as well. In my classroom at UCSD I get very bright kids; the only kids brighter are the Caltech students. I ask these wonderful kids in my class, "How many women in this room eat meat four or five times a week?" No hands go up. "How many eat it twice a week?" One or two hands go up. "How many don't eat meat?" All the rest of the hands go up. I say, "where are you getting your iron?" "Oh, Dr. Saltman, don't worry about it," they say. "We love dark-green leafy vegetables." Do you know how much broccoli you have to eat to get one U.S. RDA of iron? Eight and a half pounds. You can get a lot of reading done on that kind of diet. ...
Some of you will say, "Oh, not to worry, doc; I eat fish and chicken." Do you eat three times as much fish and chicken as you would if you ate red meat? That's the analytical chemistry of how much iron, how much copper, how much zinc is in fish and chicken compared to red meat. If you still insist that red meat ruins your karma, I suggest an iron supplement.
When the Dietary Guidelines for Americans ... came out in its first edition, it was considered government policy for a healthy America. They gave that up. Now, if the United States of America consulted with good scientists and physicians, and thought rationally about dietary matters, and then came up with this set of guidelines, is it any wonder that people go into the supermarkets wondering about the labels? Have you read the label on your favorite breakfast food lately? One of my students told me this one: She went into a supermarket and was going to buy a low-cal chocolate pudding. She compared it with the regular chocolate pudding of the same brand and discovered the low-cal was three times the price. But in reading the labels of the two packages she couldn't figure out how they were different. Then she discovered, in the directions for preparation, how the one becomes low-cal, low-fat chocolate pudding: you make the low-cal pudding with skim milk.
Getting back to our national guidelines, we come to: "Choose a diet low in fat, saturated fat, and cholesterol." Where did that come from? Why do you include cholesterol with fat? Well, it's a lipid, isn't it? Any everyone knows that cholesterol is bad for you, don't they? Does Judith Taylor, the first person to derive all her nutrients from TPN, have cholesterol in her body? You bet. She has as much as you do; she makes it all herself. You make 85 percent of your cholesterol yourself; you can take or leave the other 15 percent. Some people make too much cholesterol because they've got lousy genes or are obese. And as for fat-is saturated fat different from unsaturated, monounsaturated, or polyunsaturated fat? Recent studies show them all coming out about the same. A calorie is a calorie is a calorie. A lipid is a lipid is a lipid. Polyunsaturated fatty acids are essential. That's what lecithin has in it. Why is the government telling us to avoid these things?
"Choose a diet with plenty of vegetables, fruits, and grain products." ... Do you want to know what's the most nutritious food in terms of its nutrient density that you can buy in a supermarket? Pizza. I'm serious. All the nutrients from the bag are in a well-made pizza. ... So what is this "vegetables, fruits, and grains" stuff all about? The greatest thing about a vegetarian diet is that you can't eat enough of it to make you fat.
The next bit of policy tells us to use sugars moderately. Does that include polysaccharides and complex carbos? It doesn't say, but it implies that all sugars are bad. Do you know what food most promotes tooth decay? Dried fruits. They stick to your teeth and rot them. The next worst food is a "healthy" granola bar.
The next item-salt and sodium-I've already discussed, and that brings us to the last point: "If you drink alcoholic beverages, do so in moderation." Moderation in whose mind's eye? Actually, the statistics are pretty clear on this one, and I believe them and I practice them. I drink two glasses of wine a day-for medicinal reasons only, of course. Wine does reduce coronary heart disease, stroke, and stress. That's the good news. The bad news is that zinfandel has no calcium. I supplement calcium.
When my book, The University of California San Diego Nutrition Book, first came out, I went on a book tour. I was in Cleveland, and there's this disc jockey, a real tough cookie, who was going to interview me. He'd read my book. I knew that because he'd underlined a lot of passages. (I get very nervous when I see that. It means the kid's been studying and I'm in trouble.) So he starts off by asking me what I think of some currently popular life-extension diet. I said, "My friend, the issue isn't extending life; as far as I'm concerned the issue is the quality of life." Then this rascal goes right for the jugular. He says, "Dr. Saltman, would you define the quality of life for me?" So I blurted out the following definition, and I leave you with this:
I said that for me, personally, it's to be sound of mind and sound of body and free of pain. That's one quality. The second quality of life for me is to love and be loved. And the third quality is to share good wine and good food with people you love and who love you, and who are sound of mind, sound of body, and free of pain. May you be so blessed.
[This article was adapted from Professor Paul Saltman's general-session speech at Caltech's Seminar Day last May, which appeared in the Summer 1995 issue of Caltech's alumni magazine, Engineering and Science, as "The Yang of Nutrition... The Yin of Food," and in turn was adapted from his address to the International Symposium on Nutrition and Fitness in Beijing in October 1994. His Seminar Day talk, was - according to Engineering & Science, "extremely well received, [and] precipitated an alumni run ... on Saltman's book, The University of California San Diego Nutrition Book (coauthors Joel Gurin and Ira Mothner; Little, Brown and Company, 1987, 1993).]