The Debate over Supplements

The Best Alternative Medicine
by Kenneth R. Pelletier

(Page 3 of 5)

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.

Copyright © 2000 by Dr. Kenneth R. Pelletier, Inc.

About the Author

Dr. Kenneth R. Pelletier is a clinical professor of medicine at the University of Maryland and the University of Arizona Schools of Medicine. He is a medical and business advisor to NIH, the World Health Organization (WHO), and major corporations, including American Airlines, Medtronic, Disney, Merck, Ford, Microsoft, Blue Cross, Blue Shield, and United Healthcare. As director of the American Health Association, he is the author of more than two hundred professional papers, and he was previously a clinical professor of medicine at the Stanford University School of Medicine.