Randomized, double-blind trial of chitosan for body weight reduction

Abstract

Background: Overweight and obesity is a prevalent and costly threat to public health. Compelling evidence links overweight and obesity with serious disorders such as cardiovascular diseases and diabetes. Dietary regimen are notoriously burdened with poor compliance. Chitosan is promoted in the US and other countries as an oral remedy to reduce fat absorption and has now been incorporated as a major constituent into several overthe-counter remedies. The primary aim of this study is to investigate the clinical effectiveness of oral chitosan for body weight reduction. Methods: Thirty-four overweight volunteers were included in a randomized placebo-controlled double-blind trial. Subjects were assigned to receive either four capsules of chitosan or indistinguishable placebo twice daily for 28 consecutive days. Measurements were taken at baseline, after 14 and 28 d of treatment. Subjects maintained their normal diet and documented the type and amount of food consumed. Adverse effects were assessed and compliance monitored. Results: Data from 30 subjects were entered into an intention-to-treat analysis. After four weeks of treatment, body mass index, serum cholesterol, triglycerides, vitamin A, D, E and b-carotene were not signi®cantly different in subjects receiving chitosan compared to those receiving placebo. Vitamin K was signi®cantly increased after four weeks in the chitosan group compared with placebo (P`0.05). Compliance was 91.5% and 96.0% for chitosan and placebo groups respectively. Conclusion: The above data suggest that chitosan in the administered dosage, without dietary alterations, does not reduce body weight in overweight subjects. No serious adverse effects were reported.

Chitosan supplementation does not affect fat absorption in healthy males fed a high-fat diet, a pilot study

“…The second line of evidence comes from two recent trials where chitosan use without energy restriction for 4 or 8 weeks failed to increase weight loss over placebo. 21,22 The final, and most conclusive, line of evidence comes from the data reported here: chitosan did not increase fecal fat excretion and thus failed to act via its proposed mechanism. We did not test multiple chitosan products, but we do conclude that the central claim associated with this particular chitosan supplement, fat malabsorption, is false and the associated claims for weight loss are therefore misleading.…”

“…In two more recent studies, chitosan was used at 2 g=day for 4 weeks or 2.4 g=day for 8 weeks without dietary energy reduction and no effects on body weight were observed. 21,22 In advertising materials for chitosan, it is claimed that it can prevent the absorption dietary fat, up to 120 g per day with this particular product, and can thus be used as a weight control aid for individuals maintaining a high fat diet. 4 There are three lines of evidence that contradict this claim.…”

“…On an energetic basis, if this weight loss were attributed to fecal fat loss alone, excretion of more than 100 g dietary fat=day would be required. Because the studies used chitosan in conjunction with a reduced energy diet (4.18 -5.02 MJ=day) containing only about 34% of energy from fat, 21,22 we calculated that subjects were eating only 38 -45 g of fat per day. Therefore, if chitosan contributed to weight loss, one must conclude that it acted through mechanism(s) other than lipid malabsorption.…”

Chitosan decreases total cholesterol in women: a randomized, double-blind, placebo-controlled trial

“…Studies in rats also demonstrated the cholesterol-reducing activity of dietary chitosan (Sugano et al, 1980;Gallaher et al, 2000). However, a double-blind, randomized, placebo-controlled clinical study did not find significant differences in body mass index, serum cholesterol or triglycerides in subjects receiving chitosan for four weeks, compared to those receiving placebo (Pittler et al, 1999). In contrast, other authors reported that chitosan significantly lowered serum LDL cholesterol after 8 weeks of treatment (Wuolijoki et al, 1999).…”

Effects of a Stimulant-Free Dietary Supplement on Body Weight and Fat Loss in Obese Adults: A Six-Week Exploratory Study

“…Chitosan, a deacetylated derivative of chitin that is found in the exoskeleton of shrimp and crabs, is a unique, indigestible, nonplant fiber that may aid weight loss by reducing fat absorption in the intestinal tract. Whether chitosan can cause weight loss is inconclusive, as results vary from no effects 55 on body weight loss to mild 27 or moderate effects. [45][46][47] The unique positive charge of chitosan allows it to bind to negatively charged lipids and form a chitosan-fat gel 4-to 5-fold its original weight, causing the lipids to be trapped and excreted.…”