Combined Nutritional Disorders
Being at risk for one of the nutritionally related diseases does not preclude the possibility that we may be at risk for another. Sometimes, a risk for one increases our chances of being at risk for another. For example, people at risk for obesity are more likely to be at risk for hypertension, hyperlipidemia, and diabetes. All of these diseases seem to run in the same families. Certain environments and dietary factors are common among them. A diet to prevent obesity can be modified to also protect one against hypertension or diabetes or atherosclerosis? Regardless of which combination of risks we have, we can undertake a diet that offers maximum protection without being overly restrictive. In this chapter, we will point out those combinations that are likely to go together and the dietary principles that should be considered in making our food choices.
Two kinds of dietary manipulations can reduce our risks. There are those diseases in which too much of a nutrient or combination of nutrients increases our risk; and there are those attributed to too little of one or more nutrients. Atherosclerosis, hypertension, obesity, diabetes, and cancer are diseases of excess. Osteoporosis and anemia are caused by deficiencies. Thus, to lower our risk for any disease in the first group, we must restrict our intake of certain nutrients. To lower our risk for osteoporosis and anemia, we must increase our intake of certain nutrients. Fortunately, no nutrient that must be reduced to protect us against one illness must be increased to protect us against another. A satisfactory diet can be constructed regardless of how many of these illnesses are rated at high risk for us.
The number of nutrients that must be altered to reduce our risk for all these diseases is small (only seven): calories, fat, salt (sodium), calcium, iron, zinc, and folic acid. A diet low in calories, fat, and salt, and high in calcium, iron, zinc, and folic acid would protect us against all of the diseases. Such dietary adjustments are not only reasonable, but some experts advise that all Americans should use them to lower their risks for all the diseases discussed. The Prudent Diet is an ideal starting plan for most of us.
We do not think that everyone has to change his or her diet this way. The major benefits from any of these dietary changes are specific to individuals at high risk for a certain disease. There is no reason to change your diet if it would be of little personal benefit. However, a regimen such as the type advocated above is healthy for everyone, and it can usually be achieved without major inconvenience. Certainly, anyone at risk for more than one disease can simultaneously lower all the risks by changing his or her diet. It is rarely necessary to make all of these changes. Those who are at risk for one disease influenced by excessive intake will probably be at risk for another influenced by the same excess. Those who are prone to a disease influenced by deficient nutrient intake will be prone to any other disease similarly influenced. This is true for several reasons. First, the genetic factors that increase risk for atherosclerosis, obesity, hypertension, and diabetes seem to be linked (occur together). Second, the diseases of nutrient deficiencies (osteoporosis and anemia) occur almost exclusively in women. Finally, the lifestyles of most people generally place them in one group (in which excesses must be avoided) or the other (in which deficiencies must be corrected), but rarely in both. Let us therefore examine these groups from the viewpoint of someone at risk for more than one disease.
The diseases of excess are atherosclerosis, hypertension, obesity, diabetes, and certain cancers. The nutrients are calories, fat, and salt consumed in excessive amounts. Salt (sodium) is specific for hypertension. Thus, if the combination of diseases for which your score was high included hypertension, you must limit your salt intake as outlined in the chapter on hypertension. Calories and fat are inextricably linked. Fat is the most calorie-dense nutrient and hence the major source of excessive calories. Therefore, reducing calories almost always means reducing fat, and reducing fat invariably means reducing calories. For practical purposes, we must reduce the amount of fat in our diet whether we are aiming primarily at fat reduction, as regarding atherosclerosis and cancer, or calorie reduction, as concerning hypertension or obesity; or both, as applies to diabetes. Once we have done this, we can focus on the calories independent of the fat. Hence, if calories are of primary concern, you may wish to cut them further by reducing your intake of alcohol and refined sugar, and sometimes by reducing your total intake of food particularly foods of high glycemic index (see Table 14, page 91). The steps to be taken are as follows:
Reduce the amount of total fat (for any combination of diseases).
Reduce calories further (for obesity, hypertension, diabetes).
Reduce sodium (for hypertension).
The most restrictive diet is the one for hypertension, which controls both sodium and calories. By reducing fat as discussed in the chapter on atherosclerosis, we can bring calories into balance. Thus, by only slightly modifying the diet against risk for hypertension, you will be protecting yourself from any combination of diseases. If your risk for hypertension is not significant, regardless of the combined diseases, you do not have to pay specific attention to salt reduction.
The deficiency diseases with which we are concerned are osteoporosis and anemia. Both primarily concern women. A considerable number of American women may be at risk for both. A woman at high risk for osteoporosis and anemia must pay particular attention to consuming foods high in calcium, iron, zinc and folic acid. Concurrently, she should reduce her phosphorus allowance (particularly at the same meal that supplies a considerable portion of her calcium intake). This type of diet demands the greatest knowledge of the specific nutrients in foods. As we have noted, dietary calcium comes primarily from dairy foods. Fat-free or low-fat dairy foods are more nutrient dense and hence allow us to take in other caloric sources of iron, zinc, and folic acid. Folic acid and zinc requirements have risen only moderately. The inclusion of lean meat, liver, seafoods, and certain green leafy vegetables should meet this increased requirement. As for iron, a risk score above 10 should be treated initially with iron supplements if we are at double risk. To satisfy our calcium requirement, we will be consuming foods that are low in iron (milk, cheese, yogurt, etc.). Thus, we must get our iron from only a part of our diet. If our iron requirement is very high, then it can be achieved only by consuming fortified foods (which also supply calories) or by taking an iron supplement. Conversely, meat is not a particularly good source of calcium and is high in phosphorus. Therefore, a diet that emphasizes meat reduces the availability and the absorption of calcium. Unless we eat dairy products and carefully selected plant foods (see Table 27, page 166), we will have difficulty getting our calcium requirement. Then, we need to take a calcium supplement. The following guidelines should be followed if you are at risk for both osteoporosis and anemia:
Choose foods rich in calcium, iron, zinc, and folic acid, and low in calories.
Use low-fat dairy products.
Favor nondairy sources of calcium that also contain significant quantities of iron, zinc, or folic acid.
Use fortified breakfast cereals that contain iron primarily, and folic acid and zinc when possible.
Take a calcium supplement if you cannot achieve your calcium requirement (1000 to 1200 mg per day) with the above diet. This will depend on the number of calories you are consuming.
Take an iron supplement if your risk for anemia is 10 or more.
If you are deliberately limiting calories (dieting), take a calcium supplement (500 to 1,000 mg per day) and an iron supplement (30 mg per day).
Our goal is to combine a diet that lowers our risk for osteoporosis with one designed to lower our risk for anemia. This can be achieved effectively only if we consume enough food (calories) of the proper nutrient density, and if our iron reserves are not too badly depleted. Otherwise, we should take a calcium supplement, an iron supplement, or both.
Occasionally someone, usually a woman, can be at simultaneous risk for one disease from the nutrient-excess group and one from the nutrient-deficient group. For example, she may be at risk for hypertension and anemia. If so, she must keep her weight down by controlling calories, reduce her salt intake, and increase her intake of iron, zinc, and folic acid. To do this, she must pay attention to the foods in her diet. First, how many calories can she take in without exceeding her ideal weight? If the number is below 1,800, she will have a problem getting her iron requirement; below 1,200, she will need an iron supplement no matter how careful she is about her diet. Second, she must pay special attention to the sources of zinc, folic acid, and iron (see Tables 23, 24, and 25, Chapter 7). Finally, she must avoid foods that are either naturally high in sodium or to which sodium has been added.
If cholesterol and saturated fat must be reduced, then our options for iron become fewer because this means reducing our intake of red meats and organ meats (the richest sources of this mineral). Anyone in double jeopardy for a deficiency disease and a disease of excess should consider taking supplements. This will allow us to concentrate on reducing our risks for atherosclerosis, hypertension, obesity, diabetes, or certain cancers (while protecting us against osteoporosis or anemia). Supplements, however, do not eliminate our need to emphasize dietary sources of iron, zinc, folic acid, and calcium. The best way to get these nutrients is from our food. The supplements are simple insurance. For those of you at risk for diseases of both excess and deficiency, the following principles must be observed:
Decide how many calories you need.
Reduce calories, fat, and salt as dictated by your risk in the excess category.
Increase foods as needed if you are in the deficient category.
Take a supplement—iron if you are at risk for anemia; calcium if you are at risk for osteoporosis; iron and calcium if you are at risk for both of these diseases.
This is rarely a problem for adult men. Adult women may need supplements due to:
High-risk score for nutritional anemia (iron)
Risk for osteoporosis; inability to consume large amounts of dairy foods (calcium)
Adolescent pregnancy (iron, folic acid, zinc)
Any risk score for anemia in a pure vegetarian (iron, zinc, and vitamin B-12)
Risk for osteoporosis and one of the diseases of excess (calcium)
Risk for anemia and one of the diseases of excess (iron)
Risk for osteoporosis, anemia, and one of the diseases of excess (iron and calcium)
Any woman consuming less than 1,200 calories (iron)
Risk for anemia; heavy alcohol consumption (iron, zinc and folic acid)
Nutrient supplements can be acquired by consuming fortified foods or by taking a pill containing vitamins and minerals.
Vitamins—The body is a versatile chemist. It makes thousands of different substances. There are, however, some things it cannot produce: some of the fatty acids and some of the amino acids. We call these necessary fatty acids and amino acids the “essential fatty acids” (or polyunsaturates) and the “essential amino acids.” There are some other complex substances the body needs in small amounts and that it is unable to manufacture. These are called the vitamins. They must be provided by foods (or by “vitamin supplements”) or the body will not function at peak efficiency. A serious shortage of one or more vitamins will cause one or more deficiency diseases. Extreme deficiencies are fatal.
Most vitamins are designated by a letter of the alphabet because at one time we did not know their chemical structure and could not give them a proper scientific name. In addition, there are vitamins that have proved to be two or more related substances with similar roles in the body. For example, there are several forms of “vitamins D.” In some cases, a substance found in food is a “pro vitamin” which, when consumed, is transformed into the needed vitamin itself. For instance, there are various carotenes which, after being eaten, become vitamin A.
The vitamins are usually divided into “water-soluble vitamins,” found in the watery parts of cells (and foods), and the “fat-soluble vitamins” which are dissolved in fat or in the fat part of cells. The fat-soluble vitamins are A, D, E and K. The water-soluble vitamins are the vitamin B complex, in particular B-1, B-2, niacin, pyridoxine, B-12, folic acid, biotin, pantothenic acid, and vitamin C.
Vitamin A is found in nature as the pro vitamin, carotene, in green and yellow plants and as two forms of the vitamin itself in fresh-water fish and land animals, on the one hand, and sea fish and animals, on the other. It is also found in summer butter, which is butter churned from milk collected in the summer when the cows eat fresh grass full of carotene, the splitting of which in the organism gives rise to vitamin A. Vitamin A then goes on to be secreted in the milk. (In “Golden Guernsey’s” the splitting is incomplete; some of the yellow pigment is unchanged—hence the golden color of the milk.)
Vitamin A is essential in the growth and maintenance of epithelial tissue which comprises the skin and the covering of internal cavities. It is important in the harmonious development of the bones. It is a constituent in the maintenance of the outside of the eye and is also made into a pigment in the retina of the eye, which enables us to see. This pigment is involved in a complex photochemical process essential to night and twilight vision.
Vitamin D is found in certain foods (fish liver oil, liver, eggs, summer butter) and is also formed when the skin is exposed to the sun. Because cows are exposed to sunshine in pastures, they manufacture vitamin D by conversion of cholesterol. Some of the vitamin D then is secreted into the milk and, (like vitamin A) fat-soluble, ends up in the butter fraction. Vitamin D is necessary for the utilization of the mineral calcium. Milk is often fortified with vitamin D to the level of 400 I.U. (the Recommended Dietary Intake) per quart.
Vitamin E has a number of important roles that have been described in animals. So far, vitamin E deficiency has not been identified clearly in man, except perhaps in situations where fat absorption is grievously impaired.
Vitamin K, indispensable for the proper clotting of blood, is normally manufactured by bacteria in the intestine. Newborn babies, who do not yet have bacteria in their intestines, often need a supplement of vitamin K.
Vitamin B-1, (also called thiamin) is found in whole-grain cereals and meat, among other sources. It is needed for the utilization of starches and sugars. It is also essential to a number of other chemical reactions whereby food is utilized in the body.
Niacin (nicotinic acid and nicotinic acid amide) is necessary for the respiration of the cells. The amino acid tryptophan can be changed into niacin in the body.
Pyridoxine (vitamin B-6) is involved in many chemical reactions, in particular in the utilization of protein.
Pantothenic acid and biotin are also known to be necessary factors.
Folic acid and vitamin B-12 are needed for the formation of red cells. B-12 is also necessary for the maintenance of certain nerves.
Vitamin C (ascorbic acid) found in fruits (in particular in oranges and lemons) and potatoes, is necessary for the maintenance of connective tissue, the tissue that binds together the various organs.
Remember that you need vitamins, all vitamins, each day—not C last year and E this year and X or Y or Z next year.
The daily intake levels recommended by the National Research Council are established by subcommittees of the best experts on each vitamin. These are men and women with research experience with these vitamins in clinical nutrition. The recommendations include a generous but reasonable margin of safety to cover individual differences and changing conditions. Large doses (more than 250 percent of the recommended daily intake) should be taken only with the knowledge and advice of your physician. A growing number of prevention oriented physicians are advising their patients to take mega doses (up to 2,000 percent of the recommended daily intake) of vitamin E, vitamin C, and other antioxidants such as beta-carotene. There is growing evidence that these substances can help prevent some of the harmful effects of free radicals (charged molecules) in the body. Perceived dangers of the supplements are almost nonexistent. However, one major concern is that the body can become dependent on them after prolonged use. If you take large doses of these materials and decide to stop (for economic reasons or on the advice of a professional, for example) you should taper off gradually. Abrupt withdrawal of mega vitamin supplements can lead to rebound phenomena which can cause symptoms of vitamin deficiencies even when the intake meets normal requirements.
Minerals—One may not think of food as something to be mined in addition to being planted, bred and hunted or fished for. But many of man’s most important nutrients are scratched from the crust of the earth. Several of these minerals, needed by the body in relatively large amounts, are: calcium, phosphorous, magnesium, iron, sodium, potassium, sulfur and chlorine.
Throughout our lives we need fresh supplies of calcium to replace that which is constantly called upon to perform necessary functions. Ninety-nine percent of our calcium is in our skeleton, all but one percent of which is in the bones, the rest in the teeth. The remaining one percent which is not in the skeleton makes the muscles, including the heart, contract; aids in blood clotting; and is concerned with the nourishment of cells, the conversion of food to energy, and the supply of an ingredient that facilitates the transmission of nerve impulses.
Closely allied in the body with calcium and vitamin D is phosphorous. It is mostly in the skeleton and accounts for about one percent of body weight. Phosphorous is also essential for the chemical reactions whereby energy is transferred from food for the synthesis of body substances and for changing chemical into electrical energy in the nerves and muscles. We get phosphorous from milk and lean meats, fish and vegetables. The daily requirement is the same as for calcium: 800 mg per day.
There is about one ounce of magnesium in the body of an adult. Much of it is combined with calcium and phosphorous in the bone. The remainder is in red blood cells and in body fluids. We need magnesium to keep hormones working, to use carbohydrates for energy and to maintain muscles. There are many sources of magnesium: large amounts in whole-grain cereals (especially oats), milk, fish and shellfish (particularly shrimp), and in meat, fruit, vegetables and nuts.
Iron is an essential part of hemoglobin, the pigment of red blood cells which loosely combines in the lungs with oxygen and carries it to all the tissues. The most common anemia seen in this country is iron-deficiency anemia. It is seen in infants and young children and in women of childbearing age. It has been found to be more common among the elderly of both genders than previously suspected. Liver and kidney are rich sources of iron. Others include oysters, shrimp, sardines, most meats, dried beans, most nuts, eggs, prunes, raisins, green leafy vegetables and enriched bread and cereals.
Sodium is found mainly in the blood, lymph and digestive juices and the fluid that bathes cells. About a fifth of one percent of the body is sodium, a third of which is in the skeleton. The average American seems to eat about ten times as much sodium chloride (table salt) as he requires. Most people would do well to banish the salt shaker from the dining room table. They could satisfy their needs for sodium from reasonable amounts of milk, meat, eggs, carrots, beets and spinach.
Chlorine exists throughout the body and particularly in the acid in the stomach, which digests food. You can meet all of your requirement for chlorine from the slightest amount of table salt.
Sulfur used by the body comes from two amino acids (cystine and methionine) each of which contains sulfur. It is an ingredient of hair, nails, bones, tendons and the fluids of our joints. It performs a function in the process by which the body rids itself of common poisonous substances. Sulfur is provided by lean meat, fish, fruits and vegetables.
The body has about twice as much potassium as sodium and most of it is within the cells. Potassium is vital for maintaining the chemical balance of the cellular fluids. A small additional amount is required for the work of the muscles, especially the heart muscle. There is plenty of potassium in oranges, bananas, dried fruits, tomatoes, leafy vegetables, peas and beans, milk, meats and fish.
Iodine is what we call a trace mineral. And people who don’t get a natural supply of it—by eating seafood, for example—may be afflicted with goiter. This is one of the most clear-cut cases of what can happen when people are deficient in even the tiniest, almost-impossible-to-measure quantities of these essential trace elements or trace minerals.
Iodine is an essential component of the thyroid-gland hormones that regulate the rate at which our tissues breathe. Without it, the tissues use less oxygen, the body slows down, and eventually so does the mind. The thyroid gland enlarges in an attempt to compensate for the lack of iodine, causing the typical swelling of the neck we know as simple goiter. Goiter practically disappeared from the United States when table salt was iodized and when people living in parts of the country where the soil had little or no iodine began eating food from other sections.
About one half of the iodine in the human body is in the muscles. About a fifth is in the thyroid, the rest in the skin, the skeleton and other tissues. Its important role in the thyroid is to take part in the synthesis of the thyroid hormones that control the rate at which the principal chemical reactions of the body occur. The rest of the trace-mineral story is less simple. Not even the nutrition experts know all they would like to know about trace minerals—how they work, why the body needs them, what foods are rich in them, or even whether we know them all. And our lack of knowledge creates a fertile field for propaganda, confusion and fear.
Here is some information about several of the other trace minerals: Cobalt makes up 4.5 percent of vitamin B-12, which protects against pernicious anemia. We do not seem to need cobalt as such, only as a component of vitamin B-12, which we get from nearly all animal products. The liver and kidneys of ruminants are especially good sources. Yogurt is low in vitamin B-12.
We know that plants need boron for growth, but we’re uncertain about its importance, if any, to animals and men.
Cadmium is toxic in large amounts and may be essential in tiny ones, but we don’t know yet. The same is true of bromine.
Chromium, in an organic complex known as “glucose tolerance factor” aids insulin in getting glucose into our cells.
Manganese is needed to activate the enzymes that split amino acids off protein, and to obtain energy from the utilization of carbohydrates. The best sources are cereal bran, soybeans, other beans and peas, nuts, tea and coffee.
Selenium appears to cooperate with vitamin E in preventing certain muscle defects.
Molybdenum may be significant for the working of a number of enzymes. Molybdenum deficiency has been implicated in certain dental deformities in New Zealand.
Vanadium and silicon are known to be essential for the growth of animals, and vanadium again for their reproduction.
We measure the trace minerals in fractions of a millionth of a gram! To understand their role, we must picture each cell in our bodies as a complex factory where thousands of chemical reactions go on at the same time to make us the living, breathing, growing, regenerating organisms we are. In an ordinary factory, such chemical reactions could take place only with highly concentrated compounds at high temperatures. In the cells, they occur at body temperature, in watery fluids with enzymes acting as catalysts. These enzymes, composed of complex protein molecules, have the amazing capacity to bring specific molecules to the right position to react at the appropriate moment. Some of these enzymes contain vitamins as part of their own molecules and many do not function except in the presence of the right trace mineral. Without such activators (and each enzyme requires a particular activator), no reaction takes place. If this happens, you may become anemic, or you do not grow. In extreme cases, you may die.
Fortified foods supply the nutrient with some calories (usually from carbohydrates). Vitamin and mineral supplements usually have no calories. Whichever type you choose, remember that you are taking a supplement for a reason—your diet is low in that particular nutrient. Therefore, decide which supplement you need, and then pick a fortified food or pill containing it. For example, if you need iron and decide to use a fortified breakfast cereal, which brand should you choose? Brand X contains 100 percent of the daily requirement for all the vitamins and 25 percent of the daily requirement of iron. Brand Y contains only 25 to 50 percent of the vitamins, but 35 percent of the daily iron requirement. Brand Y should be your choice even though it is not as high in vitamins. On the other hand, if you need both iron and folic acid, you might elect Brand X, which has 100 percent of the folic acid. Look for the highest amount of the nutrient or nutrients you need. Don’t be fooled by ads saying that one cereal provides better nutrition than another cereal because it contains more of certain nutrients, when you do not need extra amounts of those nutrients.
The same principle applies to pills. Pick one that has the right amount of the nutrient you need. The rest of the vitamins and minerals it contains may be extraneous. For example, if you need 30 mg of iron per day, take a pill that contains 30 mg of iron. The amount of B-complex vitamins or vitamins C or A or D the pill contains is not important. If you need only iron, then take only iron. If you need iron and folic acid or zinc, a multivitamin mineral preparation may be appropriate. Ideally, you should take only one pill that contains all three nutrients in the right amounts. Unfortunately, such a pill might not be available. Select a pill with as much of these three nutrients as you need; but avoid pills that are very high in vitamins A and D. These nutrients are toxic if taken in excessive amounts. Another word of caution: Heed the warning labels. Iron may seem innocuous to you, but iron supplements can be fatal to toddlers! Keep all pills out of reach of children.
If you need calcium, you cannot depend on fortified foods. None contain sufficient amounts. You will need calcium in pill form. You may have heard that pills do not do any good because they aren’t absorbed. But if you have taken one that includes folic acid, did you notice how soon your urine changes color? How could that happen if you didn’t absorb the ingredients of the pill? True, some people (particularly the elderly) may not have enough acid in their stomach to dissolve some of the calcium phosphate or other solid form of calcium. In that case, it may be advisable to crush the pills (and possibly mix them with applesauce or other vehicle) before swallowing them. We discussed calcium supplements in the chapter on osteoporosis.
You will occasionally see references to “chelated” minerals, with claims that they are assimilated better. These are organically complexed metals. They bare an analogy to the way iron is contained in the heme molecule and cobalt in vitamin B-12, but are usually loosely bound to amino acids or other molecules. The original reason for chelation was the instability of vitamins in the presence of some of the mineral elements such as copper. Organic complexes of the metals did not catalyze the deterioration of vitamins (on the shelf), as did the simple metals. Almost all pills with combined vitamins and minerals include metals in chelated form. The differences in brands are probably minor (except the prices!).
Being in “double jeopardy” can be handled with a minimum of inconvenience. For most, it will mean a somewhat more restricted diet. For a few, it will also mean taking supplements. Look at the diets that lower your risk for the particular diseases in question. Combine them. Make a list of the foods to avoid in each disease. For example, if you are at risk for atherosclerosis and hypertension, you will avoid fatty meats, organ meats, eggs, non-skimmed dairy products (atherosclerosis), and luncheon meats, hot dogs, etc. (atherosclerosis and hypertension), and pickled, smoked, and highly processed foods (hypertension). In addition, you will not add much salt during cooking or use the salt shaker at the table. Somewhat restrictive? Of course, you are at risk for two serious diseases! However, you can eat an endless variety of foods: fish, fowl, lean meats, skim dairy products, fruits, vegetables, starches, grains—even wine or other alcoholic beverages in moderation. If you are at risk for obesity, this diet will be low in calories. If you are at risk for breast cancer or uterine cancer, the lowered fat and calories will reduce your risk for those diseases.
If your diabetes score is high, the diet will also reduce your risk for that disease.
If you are at risk for one or more of these diseases and are also at risk for osteoporosis or anemia, you must choose wisely from the foods that are permitted. In addition, take a calcium supplement for osteoporosis or an iron supplement (if your risk for anemia is high). Finally, if you are at high risk for atherosclerosis, hypertension, obesity, or osteoporosis, you should increase your exercise level (if you are inactive). All the changes recommended are consistent with today’s more active lifestyle and can be accomplished without great difficulty. You can continue to prepare gourmet meals at home and to dine in fine restaurants. Some of the finest restaurants now offer choices consistent with the principles outlined above. So, even for those at risk for two or more diseases, there is plenty of room for the enjoyment of good food.