Contents

Page 1
Chitosan versus Xenical.
Chitosan patents.
The synergistic effect of vitamin C.
Page 2
Sprague-Dawley rats and human rats.
Page 3
What they don't tell you about Xenical.
Page 4
My chitosan experiment and price comparison.
Page 5
Possible long-term side effects.
Possible long-term benefits.
Discussion.

"One editor said to him that it would be harmful to the journal to publish a useful treatment for the common cold. He stated that medical journals depend for their existence on the support of their advertisers, and that more than twenty-five percent of the advertisements in the journals relate to patented drugs for the alleviation of cold symptoms or for the treatment of complications of colds." -- Linus Pauling "How to Live Longer and Feel Better"

A recent issue of the medical journal, Obesity Research (June 2001), contained an interesting study that compared chitosan and Xenical: "Comparative Evaluation Of Fecal Fat Excretion Induced by Orlistat [Xenical] And Chitosan" (1). Unfortunately, it became less intriguing as I looked at the study design.

There were no problems with the inclusion/exclusion criteria or the meals: "Standardized meals were supplied throughout the 21 day study. Caloric intake was 2500 Kcal/day, of which 50% was carbohydrate, 20% protein, and 30% fat." Okay, so far. The problem with this study, however, is that they used such a LOW dose of chitosan (890 mg three times daily). Interestingly, the authors acknowledge that it is already known that low doses of chitosan do not work:

"In one study of 34 overweight volunteers, chitosan (1000 mg twice daily) had no effect on body weight after 4 weeks of treatment [2]. Similarly, chitosan (1200 mg twice daily for 8 weeks) failed to reduce body weight in a study of 51 obese women [3]. In addition, chitosan had no significant effect on total serum cholesterol in either study."

Even more suspicious is the fact that this study did not include vitamin C with the chitosan. Vitamin C (ascorbic acid) is known to have a synergistic effect on the fat blocking ability of chitosan (4-NA, 5, 6). Thus, the super high doses used in animal experiments are probably not necessary -- IF they would have used the chitosan/vitamin C combination. But they didn't. You can call me a cynic, but it looks like this study was *designed* to make chitosan look bad. Remember all the studies that used pathetically low doses of vitamin C combined with a healthy dose of misinformation to try to discredit Linus Pauling?

Interestingly, although this study used a low dose of chitosan without vitamin C, the authors unequivocally state that chitosan has "no effect on fecal fat excretion." Hmm . . . it is odd to see scientists make such a definitive statement based on VERY questionable research. I have no doubt that Spock would say "Insufficient data, Captain."

Perhaps the design of this Xenical/chitosan study and the authors comments are not so odd when you take into account the fact that "Funding for this study was provided by F. Hoffman-La Roche" (The maker of Xenical.). So this study is really like McDonald's doing a study comparing their Big Mac to the Burger King Whopper. Oh well, at least the "study" was upfront about it -- the affiliations of the scientists were also listed:

Quality chitosan & vitamin C is available at very competitive prices at WebVitamins:

Natrol Chitosan: 360 capsules (500 mg).

Twinlab C-1000: 250 capsules (1000 mg).

Written
Sep 2001
Last Update
Dec 2001

Chitosan Patents

Okay, well if that seems pretty far out then buckle your seat belts because it gets even more strange. Believe it or not, Hoffmann-La Roche Inc. (Nutley, NJ) has a patent (# 6,030,953) on a "Pharmaceutical Composition Containing Chitosan." I kid you not, click the link and you can read all the details of the patent. In fact, chitosan is such a useful substance that if you do a search you'll find that there are over 70 patents pending.

I've seen chitosan advertisements that imply that Hoffmann-La Roche patented chitosan because of its amazing fat blocking efficacy. However, the truth of the matter is that they patented it because chitosan can prevent or reduce the side effects of Xenical. Here's a quote from the patent (# 6,030,953):

"Anal leakage of oil (oily spotting) is an adverse effect [of Xenical] which is occasionally observed in patients treated with lipase inhibitors. It results from physical separation of some liquid unabsorbed dietary fat from the bulk of the fecal mass in the lower large intestine . . . Surprisingly, it has now been found that by combining a lipase inhibitor with low amounts of chitosan or a derivative or a salt thereof, the phenomenon of anal leakage of oil can be strongly reduced."

So as you can see, Hoffmann-La Roche is interested in chitosan's ability to *hold* the fat that is unabsorbed due to lipase inhibition (Xenical). So it's not quite accurate to say that this patent is a formal acknowledgment of the fat *blocking* ability of chitosan. But it IS pretty darn close. In fact, given the huge doses of chitosan discussed in the patent, it is not unfair to wonder if they were secretly thinking of using chitosan as a Xenical booster: "The chitosan compound is preferably present in the unit dosage form in an amount of from about 500 mg to about 20 g." However, the fact that they didn't mention vitamin C in the patent argues against the booster theory. At any rate, we need to take an objective look at chitosan and the synergistic effect of vitamin C.

The Synergistic Effect Of Vitamin C

More research is needed, but scientists at the Applied Bioresearch Center in Japan have made a lot of progress in determining how chitosan works (4-NA). Chitosan is dissolved by gastric acid (HCL) in the stomach resulting in an emulsion of fat and chitosan. The chitosan gels in the small intestine, entrapping the fat droplets and preventing their digestion. However, this chitosan-HCL gel must make it through the intestines without breaking or leaking the enveloped fat.

Vitamin C reduces the viscosity of chitosan and improves its ability to mix with fat in the stomach. Scientists also believe it may increase the oil holding capacity of the chitosan gel (5). In addition, vitamin C (AsA) also improves the ability of chitosan to successfully carry fat through the intestine:

"The mechanical properties of the chitosan gels indicate that the chitosan-AsA-HCL gel was more flexible than the chitosan-HCL gel, although the hardness of the latter was higher than that of the former. In other words, the chitosan-HCL gel exhibited brittle fracture like breaking biscuits, while the chitosan-AsA-HCL gel exhibited ductal fracture like that of cheese. It is reasonable to assume that the more brittle the chitosan gel, the greater the release of alimentary fat from chitosan due to breakage of the gel while being transported in the intestines" (5).

   
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1.) Guerciolini R; Radu-Radulescu L; Boldrin M; Dallas J, and Moore R. "Comparative evaluation of fecal fat excretion induced by orlistat and chitosan." Obes Res, 2001 Jun; Vol: 9; Number: 6; Page: 364-7; PMID: 11399783.

2.) Pittler MH; Abbot NC; Harkness EF, and Ernst E. "Randomized, double-blind trial of chitosan for body weight reduction." Eur J Clin Nutr, 1999 May; Vol: 53; Number: 5; Page: 379-81; PMID: 0010369493.

3.) Wuolijoki E; Hirvela T, and Ylitalo P. "Decrease in serum LDL cholesterol with microcrystalline chitosan." Methods Find Exp Clin Pharmacol, 1999 Jun; Vol: 21; Number: 5; Page: 357-61; PMID: 0010420392.

4-NA.) Kanauchi O; Deuchi K; Imasato Y; and Kobayashi E. "Increasing effect of a chitosan and ascorbic acid mixture on fecal dietary fat excretion." Biosci Biotechnol Biochem, 1994; Vol: 58; Page: 1617-20.

5.) Kanauchi O; Deuchi K; Imasato Y; Shizukuishi M, and Kobayashi E. "Mechanism for the inhibition of fat digestion by chitosan and for the synergistic effect of ascorbate." Biosci Biotechnol Biochem, 1995 May; Vol: 59; Number: 5; Page: 786-90; PMID: 0007787293.

6.) Deuchi K; Kanauchi O; Imasato Y, and Kobayashi E. "Effect of the viscosity or deacetylation degree of chitosan on fecal fat excreted from rats fed on a high-fat diet." Biosci Biotechnol Biochem, 1995 May; Vol: 59; Number: 5; Page: 781-5; PMID: 0007787292.

7-BK.) Fox, Arnold and Adderly, Brenda. "The Fat Blocker Diet." New York: St. Martin's Press; 1997; ISBN: 0-312-17102-1.

8.) Sugano M; Fujikawa T; Hiratsuji Y; Nakashima K; Fukuda N, and Hasegawa Y. "A novel use of chitosan as a hypocholesterolemic agent in rats." Am J Clin Nutr, 1980 Apr; Vol: 33; Number: 4; Page: 787-93; PMID: 0007361697.

9.) Razdan A; Pettersson D, and Pettersson J. "Broiler chicken body weights, feed intakes, plasma lipid and small- intestinal bile acid concentrations in response to feeding of chitosan and pectin." Br J Nutr, 1997 Aug; Vol: 78; Number: 2; Page: 283-91; PMID: 0009301417.

10.) Kondo H and Osada A. "Influence of dietary fiber on the bioavailability of zinc in rats." Biomed Environ Sci, 1996 Sep; Vol: 9; Number: 2-3; Page: 204-8; PMID: 0008886332.

11.) Deuchi K; Kanauchi O; Shizukuishi M, and Kobayashi E. "Continuous and massive intake of chitosan affects mineral and fat- soluble vitamin status in rats fed on a high-fat diet." Biosci Biotechnol Biochem, 1995 Jul; Vol: 59; Number: 7; Page: 1211-6; PMID: 0007670180.

12.) Wada M; Nishimura Y; Watanabe Y; Takita T, and Innami S. "Accelerating effect of chitosan intake on urinary calcium excretion by rats." Biosci Biotechnol Biochem, 1997 Jul; Vol: 61; Number: 7; Page: 1206-8; PMID: 0009255987.

13.) Razdan A and Pettersson D. "Hypolipidaemic, gastrointestinal and related responses of broiler chickens to chitosans of different viscosity." Br J Nutr, 1996 Sep; Vol: 76; Number: 3; Page: 387-97; PMID: 0008881711.

14.) Zacour AC; Silva ME; Cecon PR; Bambirra EA, and Vieira EC. "Effect of dietary chitin on cholesterol absorption and metabolism in rats." J Nutr Sci Vitaminol (Tokyo), 1992 Dec; Vol: 38; Number: 6; Page: 609-13; PMID: 0001304604.

15.) Hollander PA; Elbein SC; Hirsch IB; Kelley D; McGill J; Taylor T; Weiss SR; Crockett SE; Kaplan RA; Comstock J; Lucas CP; Lodewick PA; Canovatchel W; Chung J, and Hauptman J. "Role of orlistat in the treatment of obese patients with type 2 diabetes. A 1-year randomized double-blind study." Diabetes Care, 1998 Aug; Vol: 21; Number: 8; Page: 1288-94; PMID: 0009702435.

16.) Melia AT; Koss-Twardy SG, and Zhi J. "The effect of orlistat, an inhibitor of dietary fat absorption, on the absorption of vitamins A and E in healthy volunteers." J Clin Pharmacol, 1996 Jul; Vol: 36; Number: 7; Page: 647-53; PMID: 0008844448.

17.) Ormrod DJ; Holmes CC, and Miller TE. "Dietary chitosan inhibits hypercholesterolaemia and atherogenesis in the apolipoprotein E-deficient mouse model of atherosclerosis." Atherosclerosis, 1998 Jun; Vol: 138; Number: 2; Page: 329-34; PMID: 0009690916.

18.) Gallaher CM; Munion J; Hesslink R Jr; Wise J, and Gallaher DD. "Cholesterol reduction by glucomannan and chitosan is mediated by changes in cholesterol absorption and bile acid and fat excretion in rats." J Nutr, 2000 Nov; Vol: 130; Number: 11; Page: 2753-9; PMID: 11053517.

19.) LeHoux JG and Grondin F. "Some effects of chitosan on liver function in the rat." Endocrinology, 1993 Mar; Vol: 132; Number: 3; Page: 1078-84; PMID: 0007679967.

20.) Kondo Y; Nakatani A; Hayashi K, and Ito M. "Low molecular weight chitosan prevents the progression of low dose streptozotocin-induced slowly progressive diabetes mellitus in mice." Biol Pharm Bull, 2000 Dec; Vol: 23; Number: 12; Page: 1458-64; PMID: 11145178.

21.) Miura T; Usami M; Tsuura Y; Ishida H, and Seino Y. "Hypoglycemic and hypolipidemic effect of chitosan in normal and neonatal streptozotocin-induced diabetic mice." Biol Pharm Bull, 1995 Nov; Vol: 18; Number: 11; Page: 1623-5; PMID: 0008593495.

22.) Jennings CD; Boleyn K; Bridges SR; Wood PJ, and Anderson JW. "A comparison of the lipid-lowering and intestinal morphological effects of cholestyramine, chitosan, and oat gum in rats." Proc Soc Exp Biol Med, 1988 Oct; Vol: 189; Number: 1; Page: 13-20; PMID: 0003186761.