CAST Award Winner Releases New Study Showing Chitosan Dietary Supplements Fail to Block Fat Absorption

Obesity expert and University of California at Davis nutrition researcher Judith S. Stern announced today the results of a study that shows chitosan does not block the absorption of fat. Therefore, chitosan dietary supplements are not valuable weight control tools as frequently promoted to consumers who purchased more than $6 million of the products in the last 12 months. Stern made her announcement in conjunction with receiving honors from the Council for Agricultural Science and Technology (CAST).

Chitosan is a derivative of the protein chitin found in the shells of invertebrates such as shrimps and crabs. Dietary supplements from chitosan are promoted as “fat blockers” or “fat trappers.” Consumers purchased more than $6 million of the top three brands of these supplements between February 1999 and February 2000. To test the validity of marketing claims that chitosan blocks the absorption of as much as 120 grams of dietary fat per day, the District Attorney’s Office of Napa County, California provided a grant for the study in a unique partnership with the National Institutes of Medicine, which funded the University of California Davis Clinical Nutrition Research Unit. Matthew D. Gades and Charles H. Halsted collaborated with Stern on the study that will be published in the American Journal of Clinical Nutrition.

The study analyzed the fat content of feces from seven healthy males consuming more than 120 grams of fat per day. It compared a four-day baseline period to a four-day chitosan-supplemented period. “The bottom line is that the chitosan made zero difference,” Stern said.

“Stern’s work on chitosan is a prime example of her ability to use science as a guide for the public and policymakers. This, along with her ability to communicate scientific information, is why CAST chose her to receive the Charles A. Black Award,” said CAST President Harold Coble who made the presentation during CAST’s meeting in Alexandria, Virginia.

Working with the Federal Trade Commission, Stern helped establish “The Healthy Weight Partnership,” a coalition from government, industry and non-profit groups to begin establishing voluntary standards for the weight control industry. Stern co-founded the American Obesity Association (AOA), a Washington DC-based lay advocacy group and helped develop the Shape Up America! and AOA Guidelines for treating obesity. She helped found and chaired the Food and Nutrition Science Alliance (FANSA) to help scientists speak with one voice. FANSA has produced valuable resources, such as publications on how to identify junk science. She is a member of the Obesity Task Force of the National Institutes of Health’s National Institute for Diabetes Digestive and Kidney Diseases. Stern is also a member of the National Academy of Sciences Institute of Medicine.

CAST presents the Charles A. Black Award annually to a food or agricultural scientist actively engaged in research who has made significant scientific contributions to his/her scientific field, and communicates the importance of science to the public, policymakers, and news media. The award is named for Dr. Charles A. Black, professor emeritus of agronomy at Iowa State University and a past president, executive vice president, and member of the founding committee of CAST.

CAST is an international consortium of 37 scientific and professional societies representing more than 180,000 member scientists. Its mission is to assemble, interpret, and communicate science-based information regionally, nationally, and internationally on food, fiber, agricultural, natural resource, and related societal and environmental issues to stakeholders–legislators, regulators, policy makers, the media, the private sector, and the public. More information on CAST and its numerous scientific reports are available at https://cast-science.org. Copies of reports are available from CAST at (515) 292-2125 or by e-mail at cast@cast-science.org.

Contact: Dr. Judith S. Stern, 925-285-8951, sternhome@aol.com; Dr. Richard E. Stuckey, 515-292-2125, Ext. 25, rstuckey@cast-science.org; Karen Edwards, 703-502-8980, karen@kcegroup.com.