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Chapter Three: Food for Thought
Many of the dietary and nutritional beliefs that were formerly accepted only by the alternative health community have in the past few decades been embraced by conventional clinicians, researchers, nutritionists, and dietitians. However, many nutritional issues remain fraught with inconsistency and controversy. Moreover, as might be predicted in a market economy, a new wave of commercial interests has entered the field, offering a bewildering array of nutritional products, which may not be helpful, and may even be injurious to optimal health. Currently, many studies are calling into question the value of some of America's most frequently consumed supplements. Thus, with a few notable exceptions, foods, rather than pills, need to be recognized as our best sources of necessary nutrients.
Even so, it is widely accepted that the American diet that accompanied industrialization has been associated with an increased incidence of degenerative diseases, including cardiovascular disease and cancer, which together cause more than two-thirds of all deaths in the United States.
Factors contributing to the decline of the American diet include the increased processing of grains, which strips them of fiber and nutrients, the overconsumption of animal protein and fats, and the heavy use of refined sugars and starches. Our food also now contains increasing quantities of additives, pesticides, drugs, and toxins. Even our soil has been depleted. These factors appear to contribute significantly to chronic diseases.
By comparison, other countries with different diets suffer fewer degenerative diseases, particularly heart disease. In Mediterranean countries, the use of largely monounsaturated olive oil as the primary source of fat confers considerable protection against heart disease. For many nonindustrialized countries, and in many Asian countries, the low consumption of animal products also helps protect people from a variety of chronic diseases.
Therefore, in keeping with the theme of "think horses, not zebras," our first step in assessing the American diet should be to pay attention to the obvious task of eating healthier foods, rather than taking esoteric and often questionable supplements.
Recognizing that the American diet was producing a health crisis of degenerative diseases, about thirty years ago the U.S. government began to address the issue of an optimal diet for the American people. As early as 1969, the Senate Select Committee on Nutrition, chaired by Senator George McGovern, held hearings, and in 1977 they issued their conclusions. Despite strong opposition from the powerful American food industry, the McGovern Committee came up with important new recommendations in the form of the United States Dietary Goals. They recommended reducing calorie intake, increasing the consumption of complex carbohydrates, reducing the consumption of refined sugars, reducing overall fat consumption, reducing saturated fat consumption and balancing it with polyunsaturated and monounsaturated fats, reducing cholesterol consumption, and limiting sodium intake.
These recommendations were met with strong protests from the cattle, egg, sugar, and food-processing industries, and even the American Medical Association. In the intervening years, though, the AMA altered its antagonistic position.
In the early 1990s, the U.S. Department of Agriculture introduced a new "Eating Right Pyramid," which further deemphasized meat and dairy products. However, in the face of a new wave of protests from the meat and dairy industries, the USDA pulled back promotion of the pyramid, provoking criticism from the American Cancer Society and other agencies.
Nonetheless, many nutrition advocates, including the Physicians Committee for Responsible Medicine (PCRM), believed that the food pyramid did not go far enough. PCRM proposed its own "new" four food groups, which consisted entirely of plant foods whole grains, legumes, fruits, and vegetables. PCRM maintained that a diet centered on plant foods presents the least risk for causing heart disease, stroke, high blood pressure, obesity, colon cancer, breast cancer, and osteoporosis. Plant foods, they said, have tremendous advantages. Plant foods contain disease-fighting substances known as phytochemicals and are rich in other nutrients. They are also low in fat and high in fiber, which helps prevent cardiovascular disease and cancer and helps to remove dangerous toxins from the system.
Many people, however, prefer not to subsist solely on plant foods, but would rather add a small amount of lean meat, fish, and dairy products to their primarily vegetarian diets. This type of diet is generally referred to as a "plant-based" diet. Pure vegetarian diets can be very healthy, but many people find them to be excessively restrictive and run the risk of being protein deficient. Therefore, a plant-based diet strikes a healthy middle ground.
In October of 1997, the American Institute for Cancer Research released the first sweeping report on diet and cancer since the 1980s. The report was based upon an examination of 4,500 studies. The Institute's primary directive was to eat a plant-based diet, drink no alcohol, maintain a moderate weight throughout life, and get some exercise. According to Harvard's Dr. Walter C. Willett, one of the report's authors, "Ten to 15 years ago, the notion was that cancer was caused by too many bad things lurking in our food supply....This report really turns things around and says, cancer comes, really, from not getting enough of the good things." One of the Institute's most important recommendations is to eat five servings of fruits and vegetables each day, because fruits and vegetables are a potent way to protect the body against cancer. Additionally, the report also called for meat consumption of no more than three ounces daily, which is an amount equal to about the size of a deck of cards.
Research supporting this type of diet is powerful and voluminous. Many recent studies have shown that vegetarians are nearly 50 percent less likely to die from cancer than nonvegetarians. For example, Japanese women who follow Western-type diets that include meat are eight times likelier to develop breast cancer than Japanese women who eat a plant-based diet. Vegetarian diets also help prevent heart disease, since animal products are the main dietary source of saturated fat and the only source of cholesterol. Low-fat vegetarian diets, along with exercise, are also effective at controlling adult-onset diabetes.
In 1988, the American Dietetic Association issued a position paper endorsing vegetarian diets as "healthful and nutritionally adequate." According to the ADA, vegetarian diets provide adequate protein, although they generally provide less protein than nonvegetarian diets. This may actually be beneficial, as we will see later. Both vegetarians and nonvegetarians alike, said the ADA, may have difficulty meeting recommendations for iron intake. Also, vegetarians who don't eat eggs or dairy products may need to take additional vitamin B12.
It was Dr. Denis Burkitt who first promulgated the value of fiber in the diet. More recently, he has commented that while developed countries have steadily increased their intake of meat and dairy products over the last two hundred years, our bodies have not adapted to these changes in diet, and have no more use for such foods than they did twenty thousand years ago.
However, though it may be tempting to make an across-the-board recommendation that all humans should eat nothing but plant-based diets, it is just such dogmatism that has long created discord and misunderstanding on the subject of nutrition. Thus, it is important to heed the advice of pioneering nutritionist Dr. Roger J. Williams, the discoverer of pantothenic acid and folic acid, who originated the principle of "biochemical individuality." Throughout his prolific writing, Dr. Williams pointed out that each person is biologically unique, and that there is no one diet that is suitable for all. Because we are all unique genetically, we require slight variations in our nutrient intake. For example, some people don't produce enough of the enzyme lactase to properly digest milk. Environmental and lifestyle influences also contribute to our uniqueness. Furthermore, eating contaminated foods may make some people more chemically sensitive than others. Similarly, stress can affect digestion and nutritional needs. Even strenuous exercise creates an added demand for protective nutrients. Because of all of these factors, it is wise for each person to develop his or her own unique nutritional program.
Under the NCCAM grant at the Stanford University School of Medicine, the research team of Dr. Christopher Gardner, Dr. John W. Farquhar, and Dr. John B. Cooke has undertaken a number of innovative studies focused on plant-based diets. One study of a commercial garlic supplement was consistent with other studies indicating that garlic had little or no effect in lowering LDL cholesterol. Studies are under way in 1999 and into 2000 on the effects of phytoestrogens and soy protein on cholesterol, bone density, and breast cancer in postmenopausal women. One of the most innovative studies is to compare a plant-based diet to the currently recommended avoidance of fat and cholesterol diet. This research is oriented to determining an "optimal" diet that is as concerned with what is in a diet, phytonutrients, as with what is left out. Innovative research such as this will yield reliable, clear guidelines to create an optimal diet based on science rather than on marketing.
Nonetheless, for most people, research now clearly shows that a plant-based diet offers the most protection against the most common degenerative diseases.
Fiber. Eating a plant-based diet provides high levels of fiber. Water-soluble fibers, such as gums and pectins, protect against heart disease and diabetes by binding in the gut with bile acids, which contain cholesterol, thus preventing the reabsorption of these bile acids. Water-soluble fibers also delay glucose absorption and gastric emptying, which stabilizes blood sugar levels. Water-insoluble fibers, celluloses and hemicelluloses, protect against colon cancer by absorbing water, increasing stool volume, and speeding the passage of stool through the bowel. They also dilute the concentration of toxic bile acids, which can contribute to cancer. Presently, Americans consume an average of ten to fifteen grams of fiber per day, but should eat about twenty-five to thirty-five grams.
Recently, some nutrition experts expressed concern that high fiber consumption might inhibit the absorption and availability of minerals such as calcium, zinc, and iron. However, population studies disproved this.
Antioxidants. Our bodies are constantly exposed to "free radicals," or highly reactive molecules that can damage the body and are associated with degenerative diseases.
Fruits and vegetables are rich in substances known as phytochemicals, some of which act as antioxidants, protecting us against free radicals. Many phytochemicals in our foods have not yet been identified. This is a powerful argument for the use of whole foods rather than supplements. Another argument for this is that fruits and vegetables absorb more free radicals than isolated free-radical-scavenging vitamins, such as C and E. For example, 34 cup of cooked kale can neutralize as many free radicals as 500 mg of vitamin C, or 800 IU of vitamin E, even though kale contains only 40 mg of vitamin C and less than 10 IU of vitamin E.
Other important phytochemicals occur in rice, tea, and spices. Cruciferous vegetables, including cabbage, broccoli, cauliflower, and Brussels sprouts, contain phytochemicals that seem to be protective against cancer. Some phytochemicals also appear to be helpful for minor illnesses, such as colds.
Fats. Government guidelines say that we should consume no more than 30 percent of total daily calories as fat. Actually, optimal fat intake may be much lower, perhaps 15 to 20 percent, or even less. To reverse coronary heart disease, Dr. Dean Ornish cuts fat to a mere 10 percent of total calories, and cholesterol to 5 mg. Most recently, concern has been raised from research that such an extremely low-fat diet may increase triglycerides and lower HDL, which would actually have the effect of increasing heart disease risk for some individuals. This contrasts with the American Heart Association's recommendation of 30 percent of total calories as fat and 300 mg of cholesterol.
Besides increasing the risk of cardiovascular disease, a high-fat diet also increases the risk of cancer, obesity, and diverticulitis, which is an inflammation of the colon due to pockets of stagnant digested matter.
There are three kinds of dietary fats: saturated, polyunsaturated, and monounsaturated.
Saturated fats are primarily found in animal foods and in tropical oils, such as coconut and palm oil, which are solid at room temperature. These fats can be the most harmful, because they easily clog arteries.
Polyunsaturated fats are found in safflower, sunflower, corn, and fish oils. They contain both omega-6 and omega-3 essential fatty acids (EFAs). Theoretically, humans evolved on a diet that consisted of small and approximately equal amounts of omega-6 and omega-3 fatty acids, but now most people eat about twenty times more omega-6 than omega-3.
Omega-6 is useful in repairing injuries and causing blood to clot and blood vessels to constrict. Omega-3, however, inhibits blood clotting, relaxes smooth muscles in blood vessel walls, and protects against heart arrythmias, thereby reducing the risk of heart disease. Many foods are rich in omega-3 EFAs, including cold-water fish, such as salmon and mackerel, and flax and flaxseed oil. Smaller amounts of omega-3 fatty acids are contained in great northern, navy, kidney, and soybeans. Among oils, flaxseed oil and canola oil are high in omega-3 EFAs, and so are soy, pumpkin seed, evening primrose, borage seed, walnut, and black currant oils. Actually, the best source of omega-3 fatty acids is flaxseed oil. It contains 50 percent omega-3, compared to the 10 percent found in canola oil.
With the discovery of the relationship between cholesterol and heart disease, Americans were encouraged to switch from animal fats, such as butter, to polyunsaturated fats, including the oils we just discussed. Unfortunately, this solution presented another set of problems. When these oils undergo metabolism, they are highly susceptible to lipid peroxidation, or rancidity, which gives rise to harmful free radicals. Most researchers now believe that it is better to use monounsaturated fats, which not only reduce the risk of lipid peroxidation but also reduce LDL, or bad cholesterol, while maintaining high levels of HDL, or good cholesterol. Olive oil and canola oil are high in monounsaturated fats.
Margarine is a polyunsaturated oil that has undergone hydrogenation to make it solid at room temperature. However, hydrogenation creates man-made molecules called trans-fatty acids, which may interfere with metabolic functions. Thus, in the rush away from butter, many people may have ended up compromising their health.
Nonetheless, very recently, some researchers concluded that monounsaturated fats may not be any better than polyunsaturated fats, because monounsaturated fats may be only slightly less susceptible to oxidation than polyunsaturated fats.
Therefore, when all these complexities are weighed and sorted, the bottom-line recommendation: Cut back on all forms of fats, except omega-3!
Dairy Products. Nonfat milk is an excellent source of calcium, but dairy products may be harmful to many people. It may not even be natural for our species to consume dairy products, since the consumption of cow's milk is a relatively recent phenomenon among humans. Milk protein allergy occurs frequently among young children, and lactose intolerance is widespread throughout the world.
Milk sugar is broken down into two simple sugars, glucose and galactose. Galactose may not be easily metabolized, and may accumulate in certain tissues; this may contribute to cataracts. Whole-milk dairy products also carry the risk of contamination with fat-soluble pesticides, sulfa drugs, and antibiotics. Nonfat dairy products do not carry these contaminants.
Calcium can also be obtained from plant sources, including dark green, leafy vegetables, many beans, almonds, and some dried fruits.
People who do want to consume dairy products should use only skim or 1 percent milk and dairy products. Children under the age of two should consume whole milk, if they use cow's milk, although soy milk is an excellent alternative. For infants, breast milk is the wisest choice. Milk substitutes, such as soy, almond, rice, or goat's milk, are an option for anyone wanting to avoid dairy products. Goat's milk is metabolized differently from cow's milk and may be a useful substitute for individuals with lactose intolerance to cow's milk.
Protein. Proteins play many important roles in the body, helping in the repair and maintenance of tissues. Plant proteins lower cholesterol and may improve the function of arteries. Proteins also make up hormones, enzymes, and neurotransmitters.
However, most Americans appear to eat too much protein. Protein cannot be stored in the body, so protein that is not used for body maintenance is converted to carbohydrate. During the process, the nitrogen-containing molecules that are left are processed by the liver into urea, which is excreted by the kidneys. Therefore, too much protein in the diet may overwork the kidneys and lead to sclerosis and reduced kidney function. High levels of protein in the diet also cause the body to lose calcium by increasing calcium excretion in the urine. Animal protein causes more calcium loss than vegetable protein.
Americans, on average, consume approximately twice the government's recommended level of protein. Even athletes do not need protein in excess of the RDA, which is 51 grams per 150 pounds of body weight. There is no evidence that protein supplements or high-protein foods are helpful in athletic training, and the old idea of the high-protein training diet has been discarded by most experts.
Recent evidence has shown that vegetarians do not need to engage in complex "protein combining" in order to receive complete protein, containing all of protein's amino acid "building blocks." This practice sometimes results in excessive protein intake.
If your diet contains animal products, it is likely that your protein intake already exceeds the RDA. Since excess protein in general, and particularly excessive animal protein, is associated with increased risk of bone loss, atherosclerosis, kidney stone formation, and impaired kidney function, it is a good idea to reduce or eliminate animal foods from the diet.
Thousands of books and papers have been written about vitamins, and have created many controversies. To address these general controversies, we will focus on two specific antioxidant vitamins, vitamin E and beta-carotene, which have been of great interest to researchers in recent years. These vitamins are good examples of the complexity of the diet-versus-supplement question. They also illustrate the point that there is no easy answer to the question of whether it is possible to obtain all nutrients necessary for optimal health from the diet alone.
To better comprehend the controversy over vitamins, we must first consider the amounts of vitamins that the government deems appropriate for daily consumption. These amounts are referred to as the Recommended Daily Allowances, or RDAs. In the case of vitamin E, for example, the RDA is 12 to 15 IU. However, some proponents of supplements recommend that people take more than 1,000 IU daily!
To understand this conflict on vitamin dosages, it is important to know that the RDAs, which are revised every ten years, are the amounts of nutrients that are needed to help large population groups avoid deficiency diseases. The RDA for vitamin C is based partly on how much is needed to avoid scurvy. However, the RDAs may not be adequate to ensure optimal health. Some experts believe that the RDAs are too low, and allow minor nutritional deficiencies to occur, producing subtle symptoms that may appear to be part of the natural aging process. Thus nervousness, mental exhaustion, insomnia, improper immune function, and muscle weakness may be early warning signs of borderline deficiencies and may respond to supplementation and improvements in diet.
While diet remains the best source of meeting the RDAs for various nutrients, it may be impossible for individuals to obtain adequate quantities of some vitamins and minerals from food alone. Thus, some individuals may benefit from taking supplements. Furthermore, according to the principle of biochemical individuality, each person has unique nutritional requirements, and some may need supplements more than others.
As the following summary of research suggests, individual needs for vitamin E may vary greatly and are accentuated by those individuals who may feel they "need" vitamin E for as yet unproven benefits, such as the prevention of heart disease.
Consider the following well-documented research on vitamin E:
- A 1997 Finnish study, reported in Consumer Reports, indicated that smokers who took 50 IU of vitamin E daily had less risk of angina.
- From a 1977 study conducted in Atlanta of postangioplasty patients, those taking 1,200 IU of vitamin E daily had much less risk of reclogging of arteries.
- A recent Harvard study of 135,000 health professionals found that those who took daily vitamin E supplements had one-fourth to one-third less coronary risk than those who didn't.
- The major 1996 Cambridge Heart Antioxidant Study, reported by Stephens in 1996, found that vitamin E significantly reduced risk of nonfatal heart attacks.
It is difficult to receive high dosages of vitamin E without supplements. The richest sources are vegetable and seed oils, but these oils are high in fat. To get even 15 IU, the RDA for men, it would take 248 slices of whole wheat bread, 16 dozen eggs, or 20 pounds of bacon. Moreover, to protect against heart disease or cancer, dosage levels may need to be twenty to thirty times greater than the RDAs.
As of 1996, Dr. Kenneth Cooper, noted author and founder of the Cooper Institute, recommended 400 IU daily, and he recommended higher doses for those who engage in heavy exercise, who weigh more than two hundred pounds, or who are in other high-risk categories.
However, more than 400 IU of E a day may increase the risk of hemorrhagic stroke. People who take medications that inhibit blood clotting should not take vitamin E supplements without checking with their doctor.
One additional problem with vitamin E supplements is that they are generally in the form of alpha tocopherol, despite the fact that other tocopherols, which are found in foods, may be equally important. For example, gamma tocopherol, found in soybeans, nuts, and grains, protects against nitrogen oxides, which are free radicals that can cause DNA damage and inflammation. Nitrogen oxides are not particularly affected by alpha tocopherol. In fact, taking large amounts of alpha tocopherol increases elimination of gamma tocopherol from the body. This, again, is an argument for ingesting vitamins in foods rather than supplements.
Another important nutrient that may be better to ingest in whole foods is beta-carotene. As a supplement, it may even present health hazards for certain individuals. Beta-carotene is a precursor of vitamin A, a vitamin that can accumulate in fat cells and have toxic effects. When taken at ten times the RDA, vitamin A has been associated with birth defects.
Beta-carotene, which can be transformed into vitamin A after it enters the body, is a member of a group of substances known as carotenoids, which are the pigments in brightly colored red, orange, and yellow plants. Humans cannot synthesize carotenoids, so they must be derived from diet. However, they are not well absorbed. Carotenoids may help to protect LDL cholesterol from oxidation, thereby inhibiting atherosclerosis and heart attacks. Carotenoids also neutralize free radicals, reducing cellular damage. Different carotenoids have different antioxidant activity.
A summary of some important, representative research reveals:
- According to the Coronary Primary Prevention Study, conducted by Dr. Dexter Morris, low blood levels of carotenoids are associated with cancer and coronary disease. However, only a few high-quality RCTs have been performed.
- A 1996 study by Dr. Kenneth Cooper, reported in JAMA, found that 80,000 IU daily for 4.3 years did not affect heart disease or cancer but did lower overall mortality by 40 percent. This suggests a protective effect when beta-carotene is taken over a long period.
- In a 1997 Finnish study, male smokers taking beta-carotene actually had 18 percent more lung cancer. Another study, reported in 1996 by the National Cancer Institute, indicated a 28 percent increase in lung cancer in smokers, ex-smokers, and asbestos workers taking beta-carotene. A follow-up study, though, found increased risk only in people who smoked and also drank alcohol, or who smoked heavily. Another study found neither harm nor benefit.
One cautious conclusion we can draw is that heavy smokers and heavy alcohol drinkers should not use beta-carotene supplements. In general, it is best to get beta-carotene and other carotenoids in their natural form. It is too early to rule out beta-carotene supplementation entirely for people who are not heavy smokers or drinkers.
There are other reasons to be cautious about taking only beta-carotene since the other carotenoids are also known to have protective effects. Actually, the carotenoid lycopene, which gives tomatoes their red color, is ten times more potent than beta-carotene as an antioxidant, and apparently lowers rates of prostate cancer. A six-year study found that men of southern European ancestry were the most likely to eat tomato-based products, and the least likely to develop prostate cancer.
Sources of beta-carotene include yellow, orange, and green vegetables and fruits, such as apricots, broccoli, cantaloupe, carrots, mangoes, papayas, spinach, sweet potatoes, and turnip greens.
One final cautionary note is that the fat substitute olestra, according to some reports, dramatically interferes with the body's ability to absorb carotenoids. Since we need to get carotenoids as much as possible from the diet, olestra should be avoided.
These two much-heralded nutrients offer great promise in disease prevention. However, neither is a panacea, provident of perfect protection. In fact, for some people, these nutrients are distinctly problematic, particularly when ingested as supplements.
Surely, the same general principle holds true for many other common supplements. They can confer tremendous advantages but may not be as harmless as most people assume, and should be used cautiously.
Recently, the Third National Health and Nutrition Examination Survey showed that supplement use among adults ranges from about 36 to 51 percent. Furthermore, about 48 percent of children ages three to five take supplements. Currently, there are about six hundred supplement manufacturers in the United States, producing approximately four thousand products, with total annual sales of at least $4 billion and rising rapidly. Surveys indicate that consumers most often take supplements for disease prevention, boosting immunity, increasing energy, improving fitness, increasing alertness and mental activity, reducing stress, and treating medical problems.
For some time, the U.S. government has been concerned that consumers may be taking supplements for reasons that are not justified by scientific research. However, consumers are, for the most part, protected from unsafe products, because the government can remove supplements from the market if they present a significant or unreasonable risk of illness if used as recommended on the label.
Until recently, the literature used by distributors of dietary supplements was not allowed to contain health claims. A 1994 federal law changed this, and now publications that are reprinted in their entirety, and are not misleading, may be used in retail settings. Restrictions on labels are even more stringent; only a limited number of health claims is permitted on labels. Only four of these claims have been approved, including those dealing with the relationship between dietary calcium and osteoporosis; between folate and neural tube defects; between soluble fiber from whole oats and coronary heart disease; and between sugar alcohols and dental caries. Thus, the government remains conservative in its attitude toward supplements.
Among the supplements currently on the market are a number of controversial substances whose health benefits have not been definitively proven by RCTs. Some of the new substances have been popularized by special interest groups, such as bodybuilders, and by the lay press. Published research on such substances may lie outside mainstream medical literature.
Following is an analysis of some of the most popular of these substances. This analysis attempts to objectively assess the best existing research.
Selenium. Selenium is a trace mineral that has been the subject of extensive research and controversy. Found in brown rice, seafood, enriched white rice, whole wheat flour, and Brazil nuts, it is a powerful antioxidant, and is also a component of glutathione peroxidase, an antioxidant enzyme that helps to protect against free radical damage.
Much of the world's soil is deficient in selenium, which leads to low selenium intake. According to epidemiological studies, this accounts for an increased risk in certain regions of many kinds of cancer, including breast and colon cancer, and increased heart disease in certain regions. For example, people in selenium-depleted north-central China suffer some of the world's highest rates of esophageal and stomach cancer. However, these rates declined when some inhabitants were given selenium and vitamin E.
People need very little selenium to protect their health. For men, the RDA is 70 mcg (micrograms, or millionths of a gram), and for women it is 55 mcg. Many authorities now advise 200 to 400 mcg per day. However, 700 to 800 mcg a day may be toxic. Chronic ingestion of 5,000 mcg a day has been reported to result in fingernail changes, hair loss, nausea, abdominal pain, diarrhea, nerve problems, fatigue, and irritability. Because vitamin E enhances the effects of selenium, it can increase this possible toxicity.
Among the claims made for selenium are that it protects against cancer, improves immunity, protects against oxidative stress, prevents and treats AIDS-related pathology, and treats infertility. In actuality, though, RCTs present rather sketchy evidence of most of these claims.
- High blood pressure in pregnancy. According to a 1994 Chinese study by Han, pregnant women at risk for high blood pressure showed reduction and prevention of hypertension.
- Cancer. In 1996, an eight-year study by Dr. Larry C. Clarke at the University of Arizona revealed significant reductions in cancer mortality among people taking 200 mcg daily. However, an analysis of Dutch cancer patients indicated that cancer patients did not have low levels of selenium in their bodies. Thus, selenium's role in cancer is unproven.
- HIV. A 1996 study of HIV patients by Delmas-Beauvieux showed that those receiving selenium had higher glutathione peroxidase activity, suggesting increased immune function.
Other conditions that showed an inconclusive reaction to selenium were myotonic dystrophy, asthma, and infertility. Also, selenium showed no ability to reduce oxidative stress in children with cystic fibrosis.
People with special antioxidant needs may benefit from moderate selenium supplementation, but most claims about selenium remain unproven.
Chromium. Chromium is necessary for insulin to function properly in the human body. Insulin not only helps to metabolize sugars, but is also involved in the body's use of protein and fats. Borderline chromium deficiency may help to trigger adult-onset diabetes, but is not the underlying cause of diabetes, so chromium cannot cure the disease.
A majority of the American population takes in less than the RDA of chromium. Estimates are that 50 percent of the American population has a marginal or serious chromium deficiency, especially the elderly, pregnant women, and athletes. Therefore, supplementation with 50 to 200 mcg may be prudent.
Chromium supplementation does present some dangers. Excess dietary chromium may accumulate in the tissues and cause chromosome damage, which may contribute to cancer. Daily supplementation of 200 mcg or more of chromium picolinate, an organic form of chromium, has been linked to iron deficiencies because chromium competes with iron for transport and distribution. Trivalent chromium, the form found in the diet, has very low toxicity and a great margin of safety, but hexavalent chromium is toxic, and long-term occupational exposure can lead to skin problems, perforated nasal septum, and lung cancer.
Among the claims made for chromium are that it promotes an increase in lean body mass, increases strength during resistance training, stabilizes blood sugar levels, and lowers cholesterol. Following is an examination of these claims.
- Strength and lean body mass. A 1989 study by Dr. Kenneth Cooper reported that football players were able to increase their muscle mass after taking 1.6 mg of chromium picolinate for two weeks, with total body fat decreasing from about 16 to 12 percent. This is a relatively high intake of chromium picolinate; some athletes take as little as 600 mcg a day (which is still equivalent to the dosage level that has produced chromosome damage in animals).
However, two recent studies have contradicted the findings of this 1989 study. In a 1996 study reported in the American Journal of Clinical Nutrition, muscle mass increased with resistance training, regardless of chromium supplementation. In a 1994 University of Massachusetts study, the strength and body fat of athletes was unaffected by the supplementation.
In a recent review of the clinical literature, Dr. Pamela Peeke, a National Institutes of Health researcher, failed to establish any beneficial effects of chromium supplementation on lean body mass and enhancement of strength. It appears as if the beneficial effects of chromium supplementation may occur only in individuals with impaired chromium status.
- Weight loss. Despite the negative findings of research on athletes, chromium supplementation was found in a recent study to help overweight people lose body fat and improve the ratio of lean to fat tissue. In a 1996 study by Dr. Gilbert R. Kaats, chromium supplementation at both 200 and 400 mcg daily resulted in significant fat loss.
- Glucose tolerance. Equivocal findings exist in studies that examine whether chromium helps to normalize blood sugar levels. Chromium supplementation can improve or normalize impaired glucose tolerance, but normal glucose tolerance is not further improved with chromium supplementation, according to studies by Anderson in 1991 and Abraham in 1992.
- Blood lipids. Some researchers have found no improvement in blood lipids with chromium supplementation, while others, including Press in 1990, have obtained more positive results. Many nutritional factors influence lipid metabolism, and it may be that only certain cases are related to a low chromium status because of impairment of glucose tolerance. These cases would be expected to improve with chromium supplementation.
In conclusion, because chromium deficiency seems to be widespread in the U.S. diet, individuals with impaired glucose tolerance or lipid metabolism may benefit from chromium supplementation, especially if testing shows low blood levels of chromium. For other people, it is probably wiser to rely on nutritional sources.
Chromium can be obtained in the diet from whole grains, brewer's yeast, wheat germ, liver, broccoli, prunes, nuts, cheese, and fortified cereals. One form of yeast, known as chromium-enriched yeast, has an even higher chromium content than brewer's yeast. Both of these forms of yeast contain GTF (glucose tolerance factor) chromium, which is much better absorbed by the body than the other forms.
Coenzyme Q10. Coenzyme Q10, also known as ubiquinone, acts like a vitamin in the body and works as a catalyst in chemical reactions, even though it is not actually an enzyme. It is found in every cell in the body. It has also shown potential as an antioxidant, helping to protect against free radicals. Its primary function in the body is to help convert food into energy.
Studies have suggested that coenzyme Q10 might be useful in protecting against tissue damage in heart disease, deterioration of the retina, breast cancer, and other illnesses. However, there have not yet been many large, well-designed studies on coenzyme Q10.
Claims that have been made for coenzyme Q10 include that it slows aging by supporting immune functioning, prevents heart disease through its antioxidant action, and improves physical performance. No adverse effects have been reported.
- Protection against tissue reperfusion, or restoration of blood flow, injury. Coenzyme Q10 has shown promising results in protecting against injury from reperfusion, or rapid restoration of blood flow, to tissues after the blood supply has been stopped, as in heart attack or cardiac surgery. In a 1994 clinical trial in Italy by Chello, forty coronary artery bypass surgery patients who received 150 mg of Q10 a day for seven days before the operation showed less evidence of damage and a lower incidence of ventricular arrhythmias during the recovery period. However, when used just twelve hours before surgeries, Q10 showed no positive effect. Therefore, this application will remain a "gray area" until more large-scale studies are done.
- Congestive heart failure. Coenzyme Q10 has proven beneficial in patients with congestive heart failure. In a 1993 Italian study by Lampertico, supplementation produced improvement in a number of indicators of heart and lung function. However, the study had problems both in design and in the brevity of the treatment period. In another 1993 Italian RCT, this one by Morisco, patients using coenzyme Q10 required less hospitalization for worsening heart failure, and episodes of pulmonary edema or cardiac asthma were significantly reduced. Research in this area is still in the early stages, and it remains uncertain.
- Muscle dystrophies. Coenzyme Q10 was shown in two successful, small double-blind trials, both by Folkers in 1995, to improve physical performance in patients with a variety of muscular dystrophies and neurogenic atrophies. In both studies, definite improvement in physical performance was found in the patients receiving coenzyme Q10. However, these were very small studies, performed by an ardent supporter of the nutrient.
- Sports performance. There have been claims that coenzyme Q10 can improve sports performance, but the evidence has largely been negative. In a 1991 study by Braun, triathletes and cyclists were not found to perform better after taking 100 mg a day of Q10 for four to eight weeks.
- Cancer. Coenzyme Q10's antioxidant activity has led to suggestions that it might be beneficial in the treatment of cancer. In one 1994 study by Lockwood, none of the patients in the supplemented group died, versus the predicted or expected mortality of four; none had further metastases; and six showed apparent partial remission. However, because a number of antioxidants were used, the results cannot be attributed to Q10 alone. Thus far, nothing definitive has been proven.
- Gum disease. In a study cited by Cooper in 1996, Japanese researchers reported in 1994 that coenzyme Q10 was used successfully in adult periodontitis, both as a treatment in itself and in combination with standard nonsurgical treatment. However, in 1995, researchers disputed this success in the British Dental Journal.
In conclusion, although research on coenzyme Q10 has yielded positive findings in some areas, its most promising applications appear to be in medical situations where the supervision of a physician is required. It has not been demonstrated that coenzyme Q10 is appropriate for use as a daily nutritional supplement among healthy people.
It is preferable to get coenzyme Q10 from food sources, which include spinach, sardines, and peanuts. However, some of these foods are high in fat.
Superoxide Dismutase (SOD). Superoxide dismutase, or SOD, is an extremely potent antioxidant that protects cells against damage from free radicals. It is one of the three main antioxidant enzymes found in our cells.
Human clinical studies of SOD are still at a very early stage, but some researchers claim it slows the aging process and has potential in treating Alzheimer's disease.
SOD supplements are sold in oral form, but consumers should be aware that oral SOD products are completely destroyed in the gut. Benefits of SOD come from injectable forms.
- Skin problems and postradiation damage. Although research is limited, a promising application of SOD is for severe skin diseases and radiation damage either from prolonged sun exposure or due to radiation treatment. One researcher, Michelson, has found SOD useful in treating various skin disorders, including a very severe case of scleroderma, an autoimmune disease. He also treated severe postradiation damage with two injections weekly for three months, with substantial improvement evident in two weeks. French and Japanese researchers have also reported positive results in treating scleroderma.
- Arthritis. SOD injections are used in Europe to treat musculoskeletal inflammation and osteoarthritis. Bovine SOD, injected into the joint, has been found beneficial in controlled double-blind studies in treating osteoarthritis of the knee. However, treatment of rheumatoid arthritis has been disappointing, according to Flohe in 1988.
- Reperfusion or restoration of blood flow damage. As with coenzyme Q10, SOD is being investigated for its ability to protect against free radical damage, reducing injury to the brain and other organs caused by reperfusion, oxygen deprivation, drops in blood pressure, and increased cranial pressure after trauma.
Based on a 1993 study by Marzi of patients with multiple injuries, SOD helped to mitigate cardiovascular and lung failure, and reduced intensive care treatment and inflammation.
In a 1993 study of patients with severe head injuries, Muizelaar found that far fewer patients on high dosages of SOD died or lapsed into a vegetative state. Lower dosages did not help.
While SOD has shown exciting potential in this specialized medical application, results are not yet conclusive.
- Anti-aging. Despite claims, there is no evidence that SOD delays aging in humans. However, in animals, when both SOD and catalase are increased, maximum life span is significantly increased, according to a 1994 literature review by Warner.
Overall, SOD research is intriguing, but there is no form of SOD available to the public that will raise levels of SOD in the cells. It is much too early to recommend any use of SOD as an oral supplement, although it may have applications in specific medical treatments.
L-carnitine. L-carnitine is a substance that is essential for good health and for the regulation of fat oxidation in the body. Fatty acids are the main sources for energy production in the heart and the skeletal muscles, and these organs are especially vulnerable to L-carnitine deficiency. Symptoms of deficiency include muscle weakness, severe confusion, and angina.
Certain groups of people are at particular risk for L-carnitine deficiency, including kidney failure patients on hemodialysis, patients with liver failure, and patients receiving total parenteral (IV) nutrition. Some healthy individuals also have increased needs for dietary L-carnitine, including strict vegetarians, premature infants, pregnant women, and nursing mothers.
Dietary sources of L-carnitine are red meat, especially lamb and beef, and dairy products. There is little or no L-carnitine in vegetables, fruits, and cereals. How much L-carnitine is needed in the diet for optimal health is not known.
L-carnitine supplements are available in both the DL form and the L form. Only the L-carnitine form should be used, since the DL form has been shown to cause a muscle weakness syndrome in some individuals. Large doses of L-carnitine may cause diarrhea. Supplements may vary in purity.
Among the claims made for L-carnitine are that it increases blood flow and enhances energy production during exercise. Athletes and bodybuilders often use it.
- Cardiovascular protection. A number of well-designed clinical studies have shown that L-carnitine supplementation does have protective effects with heart patients. According to Bartels, Singh, and others, it appears to reduce angina and ischemia, and can significantly improve exercise duration. In patients with suspected myocardial infarction, it reduces infarction size, angina, cardiac death, and nonfatal infarction.
- Exercise performance. Evidence for improved exercise performance among athletes is not as convincing. In a 1997 review by Dr. Pamela Peeke, researchers found no controlled studies indicating improved physical performance in athletes. Two studies, one by Otto in 1987 and the other by Kasper in 1994, found that it did not produce an improvement for competitive runners.
- Lipid metabolism. Clinical studies are inconclusive on whether carnitine supplementation enhances the oxidation of fatty acids. A 1993 study by Natali found that L-carnitine did not influence lipid metabolism at rest, but did during exercise. However, two other studies found no effect, as reported by Decombaz in 1993 and Oyono-Enguelle in 1988.
While L-carnitine supplementation may help with deficiency states, there is little evidence that it helps healthy people.
Creatine. Creatine is an energy-producing substance that works as an energy storehouse and recharges the energy molecule adenosine triphosphate. Creatine is often used by bodybuilders and other athletes in high-intensity, explosive sports.
Dietary sources are meat and fish, though cooking can destroy it. Vegetarians are not able to get a presynthesized, concentrated form of creatine from their diet.
- Supplementation increases muscle creatine. In a 1995 study by Gordon of congestive heart failure patients, researchers found that creatine supplements did increase creatine phosphate in skeletal muscle, but only in patients whose total creatine level was relatively low to begin with. In this group, supplementation significantly increased strength and endurance.
- Sports performance. Creatine supplementation will not improve performance in endurance types of exercise, such as long-distance running, but does significantly improve performance in short-duration, high-intensity exercise. In a 1994 study of athletes by Birch in England, cellular energy production was higher and more efficient. A 1993 study by Dr. Paul Greenhaff found that creatine supplementation significantly increased performance of subjects doing maximal knee extensor exercise. According to Burke in 1996, a group of elite swimmers who received creatine supplementation showed no significant improvement. From a 1996 study of runners by Redondo, no statistically significant effect on sprint velocity was found.
Although creatine has no well-documented negative effects, supplementation does not seem necessary for daily maintenance of optimum health. However, it may help for specific power sports and bodybuilding. Athletes considering creatine supplementation for such purposes should consult with a sports medicine specialist.
DHEA. DHEA stands for dehydroepiandrosterone, a hormone that was first discovered in 1934. Its significance has been somewhat of a mystery ever since. Claims made for DHEA include that it prevents or slows the aging process, promotes weight loss, prevents or alleviates Alzheimer's disease, and combats AIDS, lupus, and some cancers. More than ten thousand scientific papers have been written about DHEA, and two international conferences have been held on DHEA research.
DHEA is the most abundant steroid hormone in our bodies. It is mainly produced in the adrenal glands, and also in the brain and skin. In the body, DHEA is converted in both men and women into estrogen, testosterone, and other steroid hormones. Production of DHEA peaks at about age thirty, and then gradually declines, reaching about 5 to 15 percent of the peak level at about age sixty. DHEA levels also drop during illness.
Research has shown that low DHEA levels in the blood are associated with heart disease, breast cancer, and a decline in immune competence. Most of the information about DHEA at present comes from animal studies, test tube experiments, and human population studies. Human clinical research is currently limited, with no long-term trials. It is not known at this point whether the effects of DHEA are due to the hormone itself or to the sex hormones and other steroids that the body produces, nor is it known which organs DHEA affects.
DHEA was found in one study to produce liver cancer in fourteen out of sixteen rats. While this does not necessarily mean that it would produce cancer in humans, if such a response were to occur in human research, DHEA would probably be banned by the FDA. Other studies have shown that DHEA supplementation can lead to increased insulin resistance, unwanted hair growth, and a drop in levels of "good" HDL. It must be remembered that DHEA is a hormone, and replacing any hormone that declines normally with aging must be carefully researched.
- Aging. Human studies on the effect of DHEA replacement on the aging process look promising, but it is too early to draw definite conclusions. In a 1994 study by Morales at the University of California at San Diego, people ages forty to seventy who took DHEA reported a substantial increase in physical and psychological well-being. However, HDL levels declined slightly in women.
- Weight control. Clinical research by Dr. William Regelson in 1996, done only on animals, showed that DHEA promoted weight loss in overweight animals even when they ate their usual diet. A 1991 human population study by Dr. Elizabeth Barrett-Connor found that lower DHEA levels in the blood were associated with increased body mass and impaired glucose tolerance.
- Menopausal symptoms. DHEA may help replace hormones in postmenopausal women, and thus protect against cancer, osteoporosis, and cardiac disease. Research is still preliminary, but in Europe, DHEA products are being marketed for menopause-related depression, and are being used in conjunction with estrogen to treat hot flashes and other menopausal symptoms. In a Canadian study by Dr. Pierre Diamond of twenty postmenopausal women, DHEA yielded reductions in blood insulin and glucose levels. Weight remained the same, but there was an improvement in the body muscleto-fat ratio, an increase in bone density, a drop in blood cholesterol, and an improvement in vaginal atrophy and secretions.
Studies by Casson in 1993 and 1995 also suggest that DHEA may help postmenopausal women, affording protection against heart disease by reducing blood lipid levels.
- Heart disease. DHEA may help to protect against heart disease in people besides postmenopausal women. A 1995 study by Herrington, reported at the New York Academy of Sciences, found significantly lower blood levels of DHEA in men who had blocked arteries. Another study reported at the conference showed DHEA supplementation reduced platelet aggregation, or the tendency of blood cells to stick together. Excessive platelet aggregation is another risk factor for cardiovascular disease.
- Immune problems. Researchers have reported that DHEA activated immune system functioning. In a 1993 study by Casson, 25 mg daily improved immune regulating response in postmenopausal women.
There is some suggestion that autoimmune disorders also respond. In a 1995 study by Dr. Ronald van Vollenhoven of the Stanford University School of Medicine, twenty-five female lupus patients who received 200 mg of DHEA showed improvement in their symptoms, had more energy, and were able to reduce their prednisone dosage.
In conclusion, while popular literature enthusiastically endorses the use of DHEA, it is too early to recommend routine supplementation. Anyone considering DHEA supplementation should have their DHEA levels checked to make sure that they are low. Serum levels of steroids should be monitored medically while taking DHEA supplements. DHEA is not fat soluble, so any fat in a meal will block absorption of the supplement. Letting DHEA absorb under the tongue is one way to bypass the intestinal tract, but some people object to the taste. Since blood levels of DHEA are highest in the morning, supplemental DHEA should be taken in the morning, to follow the body's natural rhythm.
Because DHEA is converted into steroid hormones, it is not known what its impact might be on cancers that are sensitive to hormones. There is some evidence that DHEA exacerbates breast cancer, and possibly prostate cancer. If any kind of cancer is present, DHEA supplementation should not be undertaken without medical approval.
Melatonin. Melatonin is one of the new "miracle" hormones being widely promoted today. It is produced by the pineal gland, which begins to shrink at about age twenty, with an accompanying steady decrease in melatonin production of about 1 percent a year. Calcification of the pineal gland occurs in many people over sixty.
Melatonin helps regulate the body's sleep cycle. Light suppresses melatonin production, and dark stimulates it, inducing drowsiness. Older people with sleep problems often have low levels of melatonin.
Melatonin is popular as an aid for sleep, jet lag, and insomnia caused by working at night. It has also been claimed that melatonin is a powerful antioxidant that helps with aging and immunity, and reduces the risk of cancer and heart disease.
Research on melatonin is still in the preliminary stages, with most of the work having been done in animal studies or small studies of human subjects, often not completely controlled.
- Sleep disorders. A number of small studies indicate that melatonin helps people sleep and thus improves daytime alertness and well-being. Researchers usually give 2 mg at bedtime for sleep, but some individuals need as little as 0.5 mg. Other people, however, are stimulated by melatonin, or have nightmares or hangovers. Also, a 1997 paper by the National Sleep Foundation claimed it may harm the reproductive system.
- Phase shift regulation. Some small studies of night-shift workers have shown that melatonin helps people adjust to phase shifts. However, in studies by Folkard and Dawson, the use of bright light was generally more effective than melatonin in producing adaptation to changed sleep time. Studies of phase shift regulation remain inconclusive, since the groups studied have been quite small, and since the results were not always in favor of melatonin.
- Jet lag. Larger studies of airline crews and travelers found that melatonin helped adjustment to jet lag. Optimal timing of melatonin doses to prevent jet lag was different in different studies. In a 1993 study by Petrie, 5 mg doses were begun on arrival at the destination and continued for five days. In an earlier study by Petrie, jet lag was reduced by taking 5 mg of melatonin three days before the flight, during the flight, and once a day for three days after arrival.
- Cancer treatment. In a 1996 Italian study by Dr. Paoli Lissoni, thirty patients with brain tumors received either radiation therapy alone or radiation plus melatonin. Survival was higher in patients receiving the melatonin. Also, side effects of cancer immunotherapy were reduced with melatonin. From another study of thirty patients with gastrointestinal cancer, immune functioning after surgery was improved by melatonin and immunotherapy.
- Protection of tissues. Melatonin's protective effect against potentially harmful drugs and radiation may be due in part to its antioxidant properties. It is a potent scavenger of the hydroxyl radical, perhaps the most active of all the free radicals. In this capacity, melatonin is said to help retard the aging process. It is also believed to stimulate the production of glutathione peroxidase, which plays an important role in neutralizing free radicals. Also, it has been hypothesized by Reiter in 1995 that the waning of melatonin levels acts as a switch for programmed aging of the cells.
In the final analysis, the research on melatonin remains inconclusive. In addition, there are some warnings and contraindications that need to be observed. Some studies suggest that melatonin can deepen or induce depression and exacerbate allergies. Melatonin counteracts the effects of cortisone, so patients taking cortisone should avoid it. Also, some preliminary data suggest that melatonin may cause constriction of blood vessels, may inhibit fertility, may suppress the male sexual drive, and may produce hypothermia and retinal damage. As with any powerful hormone, melatonin should not be taken by pregnant women.
Another concern is the purity of the product. Quality of this hormone is not currently regulated by the FDA, and some products are inferior.
While melatonin does seem to have exciting potential, it is much too early to recommend taking such a powerful substance as an over-the-counter supplement. Anyone considering taking it for sleep or jet lag should receive medical clearance.
Testosterone. Testosterone is the primary male sex hormone. It is produced in both men and women, and is responsible for promoting sexual desire in both sexes. Levels of testosterone decline with aging, though the decline is not as sharp and dramatic as the decline of estrogen in women at menopause. Impotence in older men is due in some cases to declining testosterone levels. If testosterone deficiencies are found in men with impotence, injections of testosterone can sometimes help to overcome the problem.
When testosterone was first identified in the 1930s, it was hailed as a miracle substance that could slow aging. It was used to restore libido and mental and physical energy among older adults. When it was discovered that large doses could promote prostate cancer, its use declined. Currently, though, it is being used increasingly to treat aging men with slight reductions in testosterone levels.
Some women, too, are receiving testosterone replacement therapy after menopause. Women normally produce small amounts of testosterone, just as men produce small quantities of estrogen. In younger women, testosterone levels rise just before ovulation, producing a surge in libido. By age forty, testosterone levels in women have declined to only half their value at age twenty, partly owing to the decline in DHEA, the hormone used by the body to make testosterone.
- Strength and muscle mass. Bodybuilders and other athletes, both men and women, have been using testosterone and other anabolic, or muscle building, steroids to build muscle and lean body mass. Unfortunately, the high doses of steroids used by athletes have been linked to heart disease, stroke, cardiomyopathy, and possibly cancer. Other adverse effects include liver toxicity, decreases in plasma testosterone, atrophy of the testes, prostate enlargement, impotence, decreased sperm count, breast enlargement in men, increased injury of muscles and tendons, increased serum cholesterol, and decreased HDL. Psychological side effects can include euphoria, aggressiveness, irritability, nervous tension, changes in libido, mania, and psychosis. Female athletes have less-well-documented side effects, including irreversible lowering of the voice, increased libido, menstrual disturbances, aggressiveness, acne, increased body hair, and clitoral enlargement.
- Arthritis. Testosterone has been studied as a treatment for rheumatoid arthritis, with equivocal results. In a 1996 study by Booji, it caused improvement in rheumatoid arthritis symptoms. However, in a 1996 study by Hall, there was no significant effect on the disease.
Testosterone is not available as a dietary supplement. It is available only by prescription and is relatively expensive, at fifty to one hundred dollars a month. Besides injections, testosterone is now available in a new patch that can be worn on any part of the body, making it easier to use. It was formerly available in the United States only by injection, or by a patch worn on the scrotum. In Europe, testosterone is available in pills, but these have not been approved for use in the United States.
To summarize, testosterone is appropriate for severe testosterone deficiency, and for older men, and perhaps women, whose low testosterone levels have caused loss of libido. However, even in small doses, it can encourage prostate tumors. Testosterone also increases the risk of stroke.
Testosterone is a very powerful hormone that can have very serious side effects, and should only be used under appropriate medical supervision.
Biochemical individuality means that we all have slightly different dietary needs, based on our genetic endowment, exercise level, metabolic function, state of health, geographic location, and other factors. To sort out what this means in terms of diet and supplement choices, professional help is available from a number of disciplines.
Before making radical changes in your diet or lifestyle, remember that in order to maintain new health behaviors, these changes need to be supported by many sources, such as family and friends. Enlist the cooperation and encouragement of family and friends, and reinforce your decisions by reading material that underscores the benefits of the changes you are planning. If you are making significant changes in your diet, such as adopting a more plant-based or vegetarian diet, make every effort to ensure that your new diet is appealing to all your senses and includes a variety of colors, tastes, and aromas. This not only whets the appetite, it also helps to ensure that your diet will provide all the protective nutrients your body requires. Even a weight-loss regimen need not produce a feeling of deprivation. A slimming diet rich in grains, legumes, fresh fruits, and vegetables can be very satisfying and appealing to the senses.
It is wise to consult with your doctor or nutritionist before undertaking any supplementation beyond the use of antioxidant vitamins such as C, E, the B vitamins, and calcium/magnesium for women who require calcium throughout their lives as one deterrent to osteoporosis. Maintaining a balanced ratio of calcium to magnesium can also be delicate. Trained professionals are able to evaluate whether any medications or health conditions would contraindicate the use of the more controversial substances discussed above.
Many of the more controversial supplements have had intriguing claims made for their anti-aging and longevity properties, and research has begun to document the potential value of some of these substances for restoring and preserving youthful vigor. However, no nutrient, supplement, or magic bullet can take the place of a balanced, well-rounded diet and a lifestyle conducive to optimal health. Regular exercise, social engagement and support, good stress management practices, a feeling of optimism, and a sense of purpose in life are all just as important as any supplements you might take in assuring you a long and healthy life. Positive mental attitude grows out of and reinforces good dietary practices. Each positive lifestyle habit you cultivate magnifies and multiplies itself throughout every aspect of your life. When you know that you have made dietary changes that will be beneficial for you, your feeling of self-worth and empowerment will improve along with your level of physical well-being. Even older adults with chronic diseases have a better prospect for survival and for less troublesome symptoms when they know that they have control over those areas in their lives where they can exercise choice.
Copyright © 2000 by Dr. Kenneth R. Pelletier, Inc.