The Nutritional Sciences Department faculty at the University of California, Berkeley, is concerned about the plethora of dietary supplements being marketed to consumers and the advertising claims being made for these products. Some of these supplements are composed of combinations of substances, which are rarely, if ever, found together in food. Almost nothing is known about the long-term effects of consuming these substances solely or in combination with other compounds. Advertising claims being made for many of these products are not substantiated by scientific research. It is our opinion that this situation has gotten out-of hand. Consumers are not being protected against possible harmful effects of long term consumption of these products, and consumer fraud appears to be rampant.

We would like to support our statement with specific examples of dietary supplements that are currently available and which are being marketed to consumers via magazine ads and commercial websites. Because of the inordinate amount of time and energy it takes investigate a dietary supplement, we have had to limit our investigation to two products. However, there are dozens of similar products available that could have been investigated.

Example #1

Dietary Supplement A, Active Ingredients according to Manufacturer:

Hydroxycitric Acid (HCA)

Gamma Linolenic Acid

L-Taurine

Chromium Picolinate

L-Phenylalanine

Korean ginseng

Octacosanol

L-Carnitine

Vitamin B6

One of the advertising claims for this supplement states that it is "100% safe to take." Yet there have been no studies investigating the long term effects of feeding this combination of ingredients to human beings or even animals. We cannot predict how these 9 different compounds may interact when given to humans simultaneously. Chemical compounds can facilitate or interfere with the digestion, absorption, and metabolism of each other as well as nutrients from food. The manufacturer/distributor has failed to reveal the quantity of each ingredient found in a single dose of this product, making it even more difficult to assess the safety of long term consumption.

Some of the compounds in supplement A have been shown to have toxic effects when taken as supplements. For example, reports from the Hazardous Substances Data Bank and Shepard's Catalog of Teratogenic Agents reveal, that phenylalanine supplementation has caused mental retardation in the offspring of pregnant rhesus monkeys. Pyridoxine (Vitamin B6) toxicity was the cause of neurological symptoms in 103 women attending a private clinic who took supplements of an average of 117 mg of this nutrient for 6 months to 5 years. (Dahlton & Dahlton, Acta Neurol. Scand., 1987).

Thus the distributor/manufacturer of this supplement has no basis for the claim that this product is 100% safe for long term human consumption.

Example # 2

Supplement B, Active Ingredient according to Manufacturer:

Chitin/Chitosan

Chitin and Chitosan are the major constituents of the exoskeletons of crustaceans such as crab, shrimp, and lobster. These compounds are also produced by fungi and brown algae. Chitin and Chitosan are biopolymers composed of glucosamine and N-acetylated glucosamine linked by glycosidic bonds.

Chitosan has been shown to markedly increase the fecal excretion of dietary fat in laboratory rats in direct proportion to the degree of deacetylation. (Deuchi, Kanauchi, Imasato, & Kobayashi, Biosci Biotch and Biochem, 1994; Ikeda, Sugano, Yoshida, et al, J Agri Food Chem, 1993) The addition of ascorbic acid to chitosan caused a significantly larger increase in fecal fat excretion, again in rats. (Kanauchi, Deuchi, Imasato et al, Biosci Biotch and Biochem, 1994) In these studies, there was a significant reduction in fat digestibility. The rats' weights and body composition before and after chitosan supplementation were not reported.

An extensive computer search of the scientific literature revealed only two scientific studies examining the effect of feeding chitin/chitosan to humans. In the first study, 8 adult healthy males were given 3-6 grams of chitin per day for two weeks. (Maesaki, Tsuji, Nakagawa, et al, Biosci Biotch and Biochem, 1993) The investigators reported a significant decrease in total serum cholesterol (188 mg/dl to 177 mg/dl) and an increase in serum HDL- cholesterol (51 mg/dl to 56 mg/dl). Although the results were statistically significant, the decreases were not remarkable. There was no mention of any changes in weight or body composition of the subjects in this study.

In the second study, two weeks of ingesting chitosan resulted in a significant increase in the fecal excretion of primary bile acids as cholic acid and chemodexoycholic acid, and a significant decrease of coprostanol. (Terada, Hara, Sato, et al, Microbial Ecology in Health and Dis, 1995) This demonstrated that chitosan had changed the bacterial flora of the intestinal tract. The researchers concluded that chitin had antimicrobial activity that could prove useful in preventing infection of wounds by direct application. As in the previous study, there was no mention of any changes in weight or body composition of the subjects. Further in vitro research has shown that chitin and chitosan have bacteriostatic, bactericidal, and candidacidal activities.

Manufacturers/distributors for dietary supplements, which include, chitin/chitosan as an ingredient generally claim that this compound causes weight loss in individuals who do not change their food intake and/or their exercise habits. There is not a single scientific study published in a peer reviewed journal to substantiate this claim. In fact, there is concern about the possible toxic effects of long term chitin/chitosan ingestion. S.S. Koide, a scientist at the Center for Biomedical Research in New York reviewed published scientific research on chitin and chitosan and summarized the findings in a 1998 article entitled "Chitin-Chitosan: Properties, Benefits and Risks" in the journal, Nutrition Research. In this article he points out that "Chitosan acts by forming gels in the intestinal tract which entrap lipids (fats) and other nutrients including the fat soluble vitamins A, D, E and K, thus interfering with their absorption." (Razdan & Petterson, British J of Nutri, 1994). Thus the long term ingestion of chitosan could result in a deficiency of one or more of these fat soluble nutrients. He also points out that dietary chitosan may influence calcium metabolism by accelerating its urinary excretion. (Wada, Nishimura. Watanabe, Takita, et al, Biosci Biotch and Biochem, 1997) This could possibly result in growth retardation in children, and reduction in bone mineral content of adults.

Koide states that, "A comprehensive study of the metabolic effect of long-term dietary supplement use of chitosan in human subjects needs to be performed." Although Koide acknowledges that chitin and chitosan lower plasma cholesterol, improve HDL-cholesterol, and promotes wound healing in short-term studies in humans, he believes there may be serious health risks associated with long-term ingestion. The two human studies that examined the effect of feeding chitin/chitosan to humans were of two weeks duration. Therefore, the effect of giving these compounds to humans for longer than two weeks is not known.

The faculty of this Department would like to go on record in support of the "Report of the Commission on Dietary Supplement Labels" submitted to The President of the United States on November 24, 1997, by Malden C. Nesheim,PhD, Chair of the Commission. This report contains recommendations for regulations and provides guidance to government agencies and the dietary supplement industry relative to safety, label statements, health claims, substantiation of claims and botanical supplements. It concerns us that no action appears to have been taken to ensure that these recommendations are implemented. We would also like to see stricter enforcement of current regulations regarding the safety of dietary supplements and advertising claims being made for these supplements.