The Extraordinary Case of Dietary Supplements

Catherine Woteki

I have been asked this evening to talk about one particular case of complementary and alternative medicine, dietary supplements. Dietary supplements are an extraordinary case because of the amount of attention Congress has given to them and because of the regulatory framework that has been established.

The legal definition of a dietary supplement is: a product that is intended to supplement the diet; that contains a vitamin, a mineral, an amino acid, an herb; or a dietary substance for use to supplement the diet, by increasing the total dietary intake (that last phrase is generally taken to mean substances like enzymes, glandular extracts, or other types of substances that might be present in foods, but are not a nutrient or herb); of a concentrate, metabolite, constituent, extract or combination of any ingredient above; and are intended for ingestion as a capsule, powder, soft gel or gel cap; and not a conventional food or sole item of the meal or the diet (Table 1).

When people talk about dietary supplements these days, they are talking about an incredibly wide range of different substances that can be assigned to two large categories. The first category is those substances for which there are demonstrated health benefits. Clearly, the vitamins and minerals, and some of the herbal products, to which Dr. Eisenberg referred, do fit into that category. The second category is everything else, for which a thorough understanding of the health benefits and risks associated with ingesting them does not exist.

We do know that the dietary supplement market has become a very, very substantial business. A recent Nutrition Business Journal article de-



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The Richard and Hinda Rosenthal Lectures 2001: Exploring Complementary and Alternative Medicine The Extraordinary Case of Dietary Supplements Catherine Woteki I have been asked this evening to talk about one particular case of complementary and alternative medicine, dietary supplements. Dietary supplements are an extraordinary case because of the amount of attention Congress has given to them and because of the regulatory framework that has been established. The legal definition of a dietary supplement is: a product that is intended to supplement the diet; that contains a vitamin, a mineral, an amino acid, an herb; or a dietary substance for use to supplement the diet, by increasing the total dietary intake (that last phrase is generally taken to mean substances like enzymes, glandular extracts, or other types of substances that might be present in foods, but are not a nutrient or herb); of a concentrate, metabolite, constituent, extract or combination of any ingredient above; and are intended for ingestion as a capsule, powder, soft gel or gel cap; and not a conventional food or sole item of the meal or the diet (Table 1). When people talk about dietary supplements these days, they are talking about an incredibly wide range of different substances that can be assigned to two large categories. The first category is those substances for which there are demonstrated health benefits. Clearly, the vitamins and minerals, and some of the herbal products, to which Dr. Eisenberg referred, do fit into that category. The second category is everything else, for which a thorough understanding of the health benefits and risks associated with ingesting them does not exist. We do know that the dietary supplement market has become a very, very substantial business. A recent Nutrition Business Journal article de-

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The Richard and Hinda Rosenthal Lectures 2001: Exploring Complementary and Alternative Medicine TABLE 1 Defining Dietary Suppements • Products intended to supplement the diet that contain a vitamin, mineral, amino acide, herb OR; • Dietary substances for use to supplement the diet by increasing the total dietary intake OR; • Concentrate, metabolite, constituent, extract, or combination of any ingredient above; AND • Intended for ingestion as a capsule, powder, softgel, or gelcap, and not a conventional food or sole item of a meal or the diet. scribes the current state of the supplements industry (Table 2). It shows that there are, first of all, many different products marketed as dietary supplements. They include vitamins, the herbals and botanicals, sports nutrition products, meal supplements as well as minerals. Together, in 1996, those five classes of products had annual sales of $10 billion that had grown in the year 2000 to be $15 billion. The traditional vitamin supplements and multivitamin supplements comprise about half of the market. Closely behind, are the herbals and botanicals, constituting about a third of the sales. Who is taking these supplements? In a review of the many different surveys conducted over the last 10 to 15 years, Janet Gregor summarized the results of several population surveys. Contrary to popular opinion, the typical dietary supplement taker is a woman. She tends to be of college or higher-level education, higher income, white, and older. Other characteristics of individuals taking dietary supplements are those that tend to believe in health promotion practices and incorporate them, or at least report that they incorporate them, into their daily activities. They tend to be non-smokers; if they drink alcoholic beverages, they TABLE 2 Dietary Supplement Sales and Market Share, 1996 Product Sales ($m) % of market Vitamins 4,900 48 Herbals & botanicals 3,000 28 Sports nutrition products 927 9 Meal supplements 618 6 Minerals 309 3 Total 10,372 100

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The Richard and Hinda Rosenthal Lectures 2001: Exploring Complementary and Alternative Medicine do so moderately, but there are also a very high proportion of abstainers. Supplement users report that they do regular cancer screening tests and they tend to be healthier. Another group frequently thought of as supplement-takers are athletes and exercisers. Indeed, Gregor’s review of recent surveys does bear that finding. Seventy-five percent of marathoners, for instance, take two or more dietary supplements. Lastly, there is a persistent impression that people who are in poor health are more likely to take dietary supplements than people who are in good health. A review of these surveys shows inconsistent information. Some studies report that people who have one or more health problems are more likely to take dietary supplements; others show that people with diagnosed hypertension, cancer, and cardiovascular disease do not take more dietary supplements than those who are not diagnosed. The question is still open as to whether people who are in ill health are more likely to take dietary supplements than those who are not. Who makes these supplements? There are about 1,000 different companies listed by the Nutrition Business Journal as makers of supplements (Table 3). The vast majority are small to mid-sized companies that assemble ingredients purchased from raw material suppliers, of which there are approximately 40 in this country. Of the 40 suppliers, eight are large pharmaceutical companies that supply over 75 percent of the vitamins that are incorporated into formulations made by the smaller companies. There are about 150 suppliers of herbal and botanical raw materials. How are the supplements marketed? The major outlets include the natural and health food chain stores, accounting for about 35 percent of the market share. They are followed by the mass merchandisers, grocery stores, and drug stores. Increasingly, grocery stores have major sections devoted to dietary supplements. The next group of vendors are multilevel marketing firms. These are direct sales companies, marketing through home parties or in door-to-door sales. Direct mail order only accounts for about six percent of the market. Surprisingly, health care TABLE 3 Producer and Sales Numbers of Dietary Supplements   No. of companies Revenue ($b) Supplement manufacturers 1,050 6.05 Vitamin raw mineral suppliers 40 0.93 Herb and botanical raw material suppliers 150 0.489

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The Richard and Hinda Rosenthal Lectures 2001: Exploring Complementary and Alternative Medicine TABLE 4 Sales and Market Shares of Dietary Supplements Outlet Sales ($b) % Market Share Natural & health food chain stores 4.5 35 Mass merchandisers 3.8 30 Multilevel marketing firms 2.9 23 Mail order 0.8 6 Health care practitioners 0.7 6 Total 12.7 100 practitioners are also a small source, about six percent, of dietary supplement sales (Table 4). As I think about alternative medicine and dietary supplements, I am reminded of Ruth Eng’s description of the “clean living movement” that has been going on in the United States since the early 1970s. Antagonism to modern agricultural practices, concern about food safety, advocacy for organic food and for vegetarianism, and strident calls for dietary change to prevent disease characterize the movement. This, though, is also part of a historical pattern. There were two early waves of clean living movements, one occurring from 1830 to approximately 1860. Some of the leading proponents of that earlier movement were William Alcott and Sylvester Graham. We remember Alcott more for being Louisa May Alcott’s father than as the Christian physiologist on which his reputation was forged. He and Sylvester Graham advocated a vegetarian diet, cold water baths, and rigorous exercise as a means for maintaining good health. We remember Graham because he advocated eating whole grain crackers, and the graham crackers on grocery shelves today were his invention. Some of the leaders in the clean living movement from 1880 to 1920 identified by Ruth Eng were John Harvey Kellogg, Horace Fletcher, and Harvey Wiley. We remember Kellogg because of the spa and sanitarium he established in Michigan, as well as for the corn flakes he served to people who participated in his programs at the sanitarium. They liked these corn flakes so much that he sent participants home with the cereal, and he started a mail order business, sending breakfast cereal. The breakfast cereals we eat today are decendents of this earlier movement. Fletcher, however, is largely forgotten. He advocated that everybody

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The Richard and Hinda Rosenthal Lectures 2001: Exploring Complementary and Alternative Medicine chew their food until it was absolutely liquid before swallowing, though there are not many proponents of that approach. Harvey Wiley is remembered for studying toxins in foods, particularly substances added to foods as preservatives and colors, as well as other purposes, and also for his advocacy for the Pure Food and Drug Act passed in 1906.The Pure Food and Drug Act established the regulatory framework under which dietary supplements were regulated up until 1994. Supplements then and now were regulated as food. Thus, the only criterion on which FDA can regulate is on the basis of safety. In 1994, Congress passed a new law, the Dietary Supplements Health and Education Act, which carved out a special niche for dietary supplements within the regulatory purview of the FDA for foods. Safety determination for dietary supplements rests with the manufacturer, and the substantiation of label claims also rests with the manufacturer. The law provides FDA no authority for premarket approval for dietary supplements with one single exception: new dietary ingredients. Lastly, there is no requirement for any manufacturer of dietary supplements to register with FDA. Thus, there is no list of companies manufacturing these particular products. The responsibility for safety of dietary supplements rests with the manufacturer, and FDA has no authority to review for safety or for effectiveness prior to marketing. In fact, effectiveness of products does not enter into FDA’s regulatory decision at all. Once a supplement is on the market, FDA must show that the supplement is unsafe before it can take any regulatory action. Unlike drugs, manufacturers of dietary supplements are not required to record, investigate, or forward to FDA reports of any injuries or illnesses that are associated with dietary supplements. There are some general concerns associated with the safety of dietary supplements. One is the toxicity of the products or ingredients within those products. A second is the potential for nutrient/nutrient interactions; this is the case where a large level of intake of one nutrient interferes with the absorption and/or metabolism of another nutrient. For example, high levels of zinc intake interfere with iron metabolism and with copper metabolism. A third category of problems is drug/nutrient interactions, to which Dr. Eisenberg referred, that I will mention again shortly. Last, is the problem of contamination with pathogens or toxins, particularly in herbal products and other animal products, such as glandular products. There is a growing history of illnesses and injuries associated with dietary supplements (Table 5). Three of the herbal products currently of

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The Richard and Hinda Rosenthal Lectures 2001: Exploring Complementary and Alternative Medicine TABLE 5 Supplements Associated with Illnesses and Injuries • Herbal and Botanicals —Chaparaal - liver disease —Comfrey - obstruction of blood flow to liver —Ephedra (Ma huang) - elevatned blood pressure, irregular heartbeat, nerve damage • Vitamins, minerals, and amino acids —Vitamins A, Niacin, Selenium —L-tryptophan -eosinophilia myalgia syndrome concern to the Food and Drug Administrations are Chaparral, which has been associated with liver disease; Comfrey, with obstruction of blood flow to the liver; and Ma Huang, associated with elevated blood pressure, irregular heartbeat, and nerve damage. Vitamins, minerals, and amino acids can also cause adverse health outcomes if taken in inappropriate amounts (Table 6). For example, vitamin A can cause birth defects, as well as acute and chronic toxicity. Niacin causes flushing of the face and heart-related symptoms. High selenium intakes are associated with toxicity and with cancer. Well over 10 years ago, there was a very large outbreak of eosinophilia myalgia syndrome linked to an amino acid supplement, tryptophan. It was marketed as being a sleep inducer, and something “natural” that one should take at bedtime to induce sleep. Under current law, the only recourse that FDA has to detect health effects from dietary supplements is adverse events reports. There is no responsibility on the part of the manufacturer to report adverse events to the Food and Drug Administration. TABLE 6 Adverse Event Reports   Dietary Supplement Foods Types Many Limited Etiologies Multiple Pathogens Sensitivities Duration Acute Chronic Acute Information source Health care providers Consumer Evaluation Extensive followup Limited

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The Richard and Hinda Rosenthal Lectures 2001: Exploring Complementary and Alternative Medicine The types of adverse events reported for dietary supplements are many and varied, compared to the types of adverse events that are related to foods. The etiologies, with respect to dietary supplements, are multiple. With respect to foods, they tend to cluster in food-borne illnesses, pathogen-related problems, as well as sensitivities and allergies. The duration of effects associated with dietary supplements can be either acute or chronic. With respect to food products, they tend to be very acute, again, because of the relationship of pathogens and adverse effects. The information source of the adverse event reports for dietary supplements are predominantly healthcare providers; whereas, for foods, they tend to be consumers. The nature of the adverse events are so severe that people go to their healthcare providers who, in turn, report to FDA. Lastly, FDA is finding that follow-up on dietary supplements is very expensive and requires far more resources than the usual follow-up on food reports, which tend to be much more limited and much easier for them to do. We are faced with a public health dilemma. Dietary supplements are now very widely used. There is a lack of industry safety and effectiveness research, largely because there is no incentive to conduct research. Under the law, as it now exists, if a substance was present in a traditional product prior to the year 1994, it is not a new ingredient. Therefore, there is no incentive for supplement manufacturers to do any research as to the safety or the effectiveness of the dietary supplement. The medical community and FDA lack knowledge about the safety of these products, their efficacy, and the substantiation for label claims. Lastly, FDA is confined to reliance on post-market surveillance and its own resource-constrained ability to investigate adverse events, which further complicates the medical community’s ability to assemble a substantial database on the safety and efficacy of these products. When a good base of science helps to inform legislation in areas of public health, we have a good public health policy. In the case of dietary supplements, excluding vitamin and mineral supplements, we do not have a sufficient base of knowledge about their safety or efficacy to inform our current policies. In fact, we have a situation where legislation has created a very perverse incentive against industry investment into the types of research that would lead to wise public policy on dietary supplements.

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