From The October 2001 Issue of Nutrition Science News

Chitosan: The Next Weight-loss Agent?

by Anthony Almada

Can a processed extract derived from shrimp and crab skeletons actually peel pounds off the human frame? The molecule derived from processed shrimp and crab shells is called chitosan, which has been shown to effectively adhere to fat in the test tube. If this works in humans, one would expect more fat in the stool and less on the body.

In a recent study, 88 overweight Asian women and men took chitosan supplements (Absorbitol) for four months without changing their diets. The results showed no greater changes in body weight, leanness, blood pressure, or a marker of insulin resistance compared with placebo.¹ In a previous one-month study, researchers found chitsoan did not affect body weight. ² Another six-month study (the longest to date) was presented at a conference this past June. Researchers restricted subjects' diets to 1,000 calories per day and they showed no weight-loss benefit with chitosan. The study also did not support the assertion that chitosan prevents muscle loss.³

However, in a more recent study, researchers found a specific brand of chitosan (Chitosol) produces significantly greater weight loss than placebo.⁴

Although it is unclear whether chitosan helps with weight loss, it is clear that all chitosan products are not equal.

Anthony Almada is a nutritional and exercise biochemist and has collaborated on more than 50 university-based clinical trials. He is the co-founder of EAS and founder and chief scientific officer of IMAGINutrition.

References

1. Ho SC, et al. In the absence of dietary surveillance, chitosan does not reduce plasma lipids or obesity in hypercholesterolaemic obese Asian subjects. Singapore Med J 2001;42:006-10.

2. Pittler MH, et al. Randomized, double-blind trial of chitosan for body weight reduction. Eur J Clin Nutr 1999;53:379-81.

3. Krotkiewski M, et al. Chitosan as an adjunct to dietary treatment of obesity. Int J Obes 2001;25 (Suppl. 2):S105.

4. Schiller RN, et al. A randomized, double-blind, placebo-controlled study examining the effects of a rapidly soluble chitosan dietary supplement on weight loss and body composition in overweight and mildly obese individuals. J Am Nutraceut Assn 2001;4:42-9.