Abstract
Background:
Many different dietary supplements are being sold in North America. The quality of the evidence supporting their efficacy covers a wide spectrum: Some are based on solid science (such as vitamin D and fish oil), whereas with most supplements there is little or no supporting evidence. Types of supplements commonly sold include exotic fruit juices (such as goji juice) and single herbs or mixture of herbs. Common claims made in support of particular supplements are that they are rich in antioxidants, induce detoxification, stimulate the immune system, and cause weight loss. Supplements are commonly sold through health food stores and by multilevel marketing. Sales may be promoted using bulk mail (“junk mail”), spam e-mails, and Web sites. A large part of marketing is based on claims that are blatantly dishonest.
Conclusions:
Whereas supplements for which good supporting evidence exists generally cost around $3–$4 per month, those that are heavily promoted for which there is little supporting evidence cost about $20–$60 per month. The major cause of this problem in the United States is weakness of the law. There is an urgent need for stricter regulation and for giving better advice to the general public.
Introduction
DSHEA allows manufacturers to make health-related claims (referred to as structure/function claims) but they are not permitted to state explicitly that the product will cure or prevent a disease. They must also state that the FDA has not evaluated the product. What this all means, in practice, is that a manufacturer may now claim that a supplement “boosts the immune system,” “makes you lose weight,” or “fights cholesterol,” provided they do not explicitly state that the supplement prevents infectious disease, cures obesity, or prevents heart disease. However, the distinction between these two sets of claims is unlikely to be meaningful to most consumers.
After the passage of DSHEA, the supplement industry in the United States took full advantage of its much wider freedom to conduct dishonest marketing. 2 Such marketing has been highly successful because most of the population has a weak grasp of science. 3 As a result, there has been a rapid increase in recent years in the sale of supplements: between 1994 and 2000, sales doubled to almost $18 billion 4 and have been steadily increasing since. Surveys reveal that around half of adults in the United States take supplements regularly. 2,5
Common Supplements
A wide variety of supplements are sold. Here are some examples.
Supplements with strong supporting evidence
Supplements where the case for benefit is strong include vitamin D, calcium, and fish oil. Multivitamins (i.e., pills containing a broad spectrum of vitamins and minerals) can be especially valuable for various groups of people, such as many elderly persons and many women during their reproductive years in order to achieve an adequate intake of iron and folic acid. But most of the marketing of supplements is concentrated on those where the supporting evidence is far weaker but the profit potential far stronger. The next section examines some of the major classes of supplements.
Exotic fruit juices
A novel type of dietary supplement is exotic fruit juices. The most common ones are acai, goji, mangosteen, and noni. They are being sold by multilevel marketing and through health food stores. Sellers claim that these products are highly beneficial. My local health food store in Edmonton, Canada charges $50 to $60 per liter for these juices. By contrast, the local supermarket sells fruit and vegetable juices for less than $3 per liter. Despite this enormous price differential, there is an absence of solid evidence that exotic fruit juices are nutritionally superior to inexpensive juices.
Herbs and herbal cocktails
Herbs are a heavily promoted class of supplements. One common problem is that there can be much variation between different brands of what is supposedly the same herb. For example, in studies of commercial samples of preparations of ginseng or St. John's Wort purchased in Canada or the United States, there were extremely wide variations in the concentration of active ingredients. 6,7 This may be due to such factors as the actual species of plant used, the part of the plant used, and the extraction method. It is also entirely possible that some manufacturers may simply be using inexpensive ingredients in place of expensive herbs. As a result, there is a lack of standardization of active ingredients.
Many products consist of a mixture of herbs, often a dozen or so. The potential customer is presented with a label that is a list of Latin names. As very little research has been conducted on mixtures of herbs, we must be skeptical as to the clinical value of such herbal cocktails. If harmful side effects occur, it will be very difficult to relate these to any specific herb or herb combination. Polypharmacy is always hazardous, whether it is based on conventional drugs or herbal cocktails.
Claimed Action of Dietary Supplements
The marketing of supplements is accompanied by claims for a wide variety of actions in the body and of health benefits. Here are some examples.
Antioxidants
It is well established that antioxidants are important for the body's defenses. Based on that fact, many supplements are marketed with a claim of being “rich in antioxidants”; the obvious implication is that such products will improve health or prevent disease. However, evidence from randomized clinical trials (RCT) has provided meager support for the concept that higher intake of antioxidants is protective against disease.
Several large RCT have been conducted in which the three major antioxidant vitamins—β-carotene or vitamins C or E—have been tested on volunteers. The major goal of most trials has been the prevention of either heart disease or cancer. The dose has typically been several times higher than the Recommended Daily Allowance. A recent major meta-analysis concluded that supplementing with these vitamins leads to an increase of about 5%–6% in all-cause mortality. 8,9 These findings strongly suggest that while foods naturally rich in antioxidants and phytochemicals, such as fruit and vegetables, are excellent for health, this benefit does not extend to purified antioxidants. The reasons for this are complex and poorly understood.
The obvious conclusion from these findings is that when sellers of supplements state in their marketing that a product has a high content of antioxidants, that is weak evidence that it will improve health or prevent disease.
Detoxification
In some areas of complementary and alternative medicine, practitioners appear to have invented an alternative scientific reality. Detoxification is an example of this. Much like antioxidants, it offers a plausible rationale for why a particular supplement will boost health. Herbal supplements, in particular, are often sold with the claim that they will stimulate the liver and thereby speed up the process of detoxification and thereby help cleanse the body. This will then, supposedly, lead to assorted health benefits, such as more energy. Detoxification is, of course, a well-established biochemical process. However, the claims being made that particular supplements will induce detoxification and lead to enhanced health are without any supporting evidence.
Immune boosters
Many supplements are marketed based on the claim that they stimulate the immune system. As with detoxification, this is most often associated with herbs. In the case of Echinacea and some other herbs, there is indeed some supporting evidence, 10,11 but in most cases the claims lack credibility. Like antioxidants and detoxification, we see a sales strategy based on a biomedical mechanism sufficiently simple that it can appeal to many people, especially those with some interest in health issues.
Weight-loss products
There is heavy marketing of supplements touted as being able to induce weight loss. Frequently, the sales promotion will display the photo of a young woman with a body mass index of about 20; the implicit message is obvious. This marketing is scarcely surprising in view of the huge obesity epidemic that has swept North America. The evidence is thin that such supplements are effective. Such supplements pose a significant risk of toxicity, as illustrated by the case of ephedra. 12 In 2003, its sale was banned by the FDA. 13
Evidence Used in the Marketing of Dietary Supplements
In recent years I have examined hundreds of sales claims made when supplements are being marketed. Several themes are consistently seen. One of the most common, as several of the above examples indicate, is weak evidence presented as established facts. The marketers of supplements like to use scientific evidence the way a drunk uses a lamp-post: more for support than illumination. Sometimes marketers go to the extreme and claim that their product cures almost everything, even cancer.
The following are the types of evidence frequently referred to and that are used to promote the sale of supplements: (1) a physiologic or biochemical change in the body (e.g., altered functioning of the immune system and therefore the body will be less susceptible to infections; or the supplement contains antioxidants and will therefore prevent disease). Often this is nothing but speculation (e.g., a supplement induces detoxification and this will improve health); (2) weak clinical evidence (e.g., a particular herb has been used for centuries as a treatment and therefore it must be effective; or evidence based on one or two small studies of dubious importance); and (3) anecdotal evidence, often from an unqualified person with a serious conflict of interest (“Many of my customers have taken [this product] and the results are fantastic.”). A slight variation of anecdotal evidence is the use of testimonials (“Harry from Chicago says: ‘Thanks to Slim Quick I have lost 35 pounds in 6 weeks.’ ”). Unfortunately, what is noticeably missing from these claims, in the great majority of cases, is hard scientific evidence, especially consistent evidence from well-conducted RCTs, with clinical endpoints, showing health benefits, and published in peer-reviewed journals.
Marketing Methods for Dietary Supplements
Direct contact with consumers
Most sales of supplements are done directly in pharmacies, supermarkets, and health food stores (HFS). Staff in HFS seldom have any proper scientific expertise. Nevertheless, whenever a customer asks for advice, the staff is usually uninhibited in recommending the purchase of one or more supplements. Studies done in the United States, Canada, and the United kingdom have shown that most recommendations lack credible supporting evidence. Moreover, when the same question is asked in different HFS, there is a huge variation in the advice given. 14 –17
This problem occurs much less often in pharmacies. As pharmacists are trained health professionals and must abide by a code of ethics, customers requesting advice are far less likely to be recommended to buy useless supplements. This was recently confirmed in a study conducted in visits made to 260 HFS and pharmacies across Canada. 18 The results of that study reveal that in 88% of times that questions were asked in HFS, the recommendations made were either unscientific (6%) or were poorly supported by the scientific literature (82%). By contrast, this occurred for only 27% of questions in pharmacies. Conversely, in two thirds of visits to pharmacies, staff gave advice considered to be fairly accurate or accurate, but this seldom occurred in HFS (68% versus 7%, p < 0.01).
Multilevel marketing
This form of marketing is practiced by many commercial enterprises, such as Avon (cosmetics). The actual salespeople, as well as everyone up the chain, receive a commission. There are many companies that sell supplements using this form of marketing. Their primary goal is the same as it is in HFS: profit, not consumer health.
Other methods of marketing
There are several other commonly employed methods for marketing supplements. Infomercials are one. These are TV advertisement that typically last for 30 minutes and air during the night. Bulk mail (“junk mail”) is another common form of advertising. Spam e-mails are an inexpensive and easy way for manufacturers to promote their dietary supplements to tens of thousands, if not millions, of people. As a result, large numbers of products are being touted, most of them of highly dubious value. In recent years, vast numbers of spam e-mails have been sent out promoting sex-related nutritional supplements. Spam e-mails typically work by directing the person to a Web site. There are large numbers of Web sites selling all types of supplements; they are, in effect, virtual HFS. They often flout U.S. law. 19
Misleading claims
Dishonesty or wild exaggerations are frequent occurrences in the marketing of supplements. In 2002, flyers were distributed in Edmonton promoting a particular product where the person behind it, Dr. Jesse Stoff, was described as “the world's leading viroimmunologist.” I could find no evidence that he had ever published a scientific article. In another case, Dr. Earl Mindell, the person behind the sale of goji juice by multilevel marketing, was referred to as “[w]idely regarded as the world's #1 nutritionist” and the product as “The biggest discovery in nutrition in the last 40 years!” ImmuGo is a product that is claimed to stimulate the immune system. During 2008 it was heavily advertised on American TV. According to the company Web site: “[it] was created by Vitamin Gene Arnold, the vitamin guru to Hollywood stars. For over 15 years, celebrities have been coming to Vitamin Gene for the latest breakthrough vitamins.” 20
This quote comes from an advertisement for apple cider vinegar capsules that was mailed to residents of Edmonton, Alberta in 2002: You can even eat as much as you like and still lose weight! … An intake of 4000 calories a day can actually help you to lose weight; each day you'll feel better, more energized, and lose weight … .(the capsules) really do help to drain off your fat deposits and eliminate that extra weight once and for all.
The object of the exercise
The purpose of all this huge marketing enterprise is, of course, to maximize sales. As mentioned earlier, there are some supplements for which solid evidence exists justifying their value; examples include vitamin D, calcium, and fish oil. Each of these costs around $3 to $4 per month. But a large part of the marketing of supplements is the diametric opposite in terms of cost-effectiveness. For example, a person inquiring in a HFS about not having enough energy, having headaches, and fear of dying of cancer will probably be advised to take several different supplements, each costing between $20 and $60 per month. This could easily add up to $100 to $200 per month. And the beneficial effect on health is likely to be trivial at best.
Regulations on the Marketing of Supplements
United States
As mentioned earlier, in 1994 Congress passed a law regulating the marketing of dietary supplements: the Dietary Supplement and Health Education Act (DSHEA). This law allows sellers of supplements to make unscientific claims, unsupported by any good evidence, and claim that these are established facts. The law is, in effect, a Bill of Rights for modern day snake-oil salesmen. This is no accident: Nestle 1 has documented that DSHEA was the result of heavy lobbying by the supplement industry. The present state of affairs has been strongly criticized in editorials in both the Journal of the American Medical Association 21 and the New England Journal of Medicine. 22
Canada
The situation in Canada was for years as deplorable as that in the United States. However, Canada has carried out a radical reform of the system. 2 A new organization, the Natural Health Products Directorate, was established with the mandate of regulating dietary supplements. By 2010, when the new system is scheduled to be fully operational, all manufacturers, importers, packagers, and labelers of natural health products (NHPs) must have site licenses, and any new NHP must have a product license. The regulations require a premarket review of products to assure that label information is truthful and that health claims are supported by appropriate types of scientific evidence. It would appear, however, that the same level of significant economies of truth apply in Canada as they do in the United States.
Conclusions
The sale of dietary supplements is highly lucrative. This has attracted many unscrupulous entrepreneurs. There is widespread use of deceptive marketing. This exploits the desire of most people for better health coupled with poor understanding of biomedical science.
Another concern is that supplements are not without risks. Some supplements induce harmful side-effects; indeed, many deaths have been reported, especially from herbs. 23 Another potential problem is that supplements may cause a person to delay taking appropriate action to deal with a treatable condition. For example, trying to lose weight or lower blood cholesterol with supplements that have little or no value may cause people to delay starting treatments that have proven value (diet and exercise, and statins, respectively).
Clearly, there is a pressing need for stricter regulation of the supplement industry. In this respect, Canadian regulations are far superior to the laissez faire laws of the United States. The general population should be advised that before buying supplements, they should seek the advice of a qualified health professional, such as a pharmacist.
Persons engaged in the marketing of supplements, including those working in HFS and pharmacies, should base their advice on credible sources of information. Several health-related organizations supply information on supplements at their Web sites. These include Mayo Clinic (
Footnotes
Disclosure Statement
No competing financial interests exist.