I have written at least 7 blogs and countless ECIR Group and social media posts on this subject but confusion continues to reign, in large part because of the persistence in using NSC to evaluate the safety of forages for horses with hyperinsulinemia.
Just this month (April, 2023), the vet and professional version of a large, well-recognized magazine for horse owners came out with an article packed with reference to NSC. NSC is nonstructural carbohydrates — things that are not part of the fibrous cellulose or hemicellulose, which are also carbohydrates.
A carbohydrate is any molecule consisting of carbon, hydrogen, and oxygen, usually with an oxygen to hydrogen ratio of 1:2. This includes all fibers, glycogen, fructan, the woody lignan in trees and bushes, as well as simple sugars and starches.
For equines with metabolic syndrome (EMS), the only dietary carbohydrate elements of concern are those that can be digested and cause an insulin spike. This includes simple sugars (ESC or enzymatically determined on the hay/pasture analysis) and starch. That’s it.
Fructan is also included in NSC but fructan is a fermentable fiber. It cannot cause an insulin spike.
For more details see this open letter to the AAEP from this time last year https://wp.me/p2WBdh-1i4 and this article on the AAEP website https://aaep.org/horsehealth/why-fructan-not-issue-pasture-laminitis .
Fructan is a storage form of sugar, like glycogen in meat. It is not the sugar itself. In humans, carb-restricted diets include plenty of meat because it does not cause an insulin spike like sugars or starch.
Huge amounts of pure fructan, given to a horse on an empty stomach all at once, by stomach tube, can cause laminitis. To date, there is no evidence that naturally ingested grass fructan causes laminitis. In 2006, van Eps and Pollitt found that 8.25 pounds of pure fructan pumped into an empty equine stomach induced profuse diarrhea, fever and laminitis in at least one foot. A higher dose of 13.8 pounds induced a systemic inflammatory response (SIRS) multi-foot laminitis caused by endotoxemia. (500 kg horse).
By comparison, a horse eating an average North American hay takes in about 7 oz of fructan over the course of an entire day, diluted by all the other compounds in the diet. It’s just not an issue.
For more reading go to http://www.ecirhorse.org.
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About ECIR Group Inc.
Started in 1999, the ECIR Group is the largest field-trial database for PPID and EMS in the world and provides the latest research, diagnosis, and treatment information, in addition to dietary recommendations for horses with these conditions. Even universities do not and cannot compile and follow long term as many in-depth case histories of PPID/EMS horses as the ECIR Group.
In 2013 the Equine Cushing's and Insulin Resistance Group Inc., an Arizona nonprofit corporation, was approved as a 501(c)3 public charity. Tax deductible contributions and grants support ongoing research, education, and awareness of Equine Cushing's Disease/PPID and EMS.
THE MISSION of the ECIR Group Inc. is to improve the welfare of equines with metabolic disorders via a unique interface between basic research and real-life clinical experience. Prevention of laminitis is the ultimate goal. The ECIR Group serves the scientific community, practicing clinicians, and owners by focusing on investigations most likely to quickly, immediately, and significantly benefit the welfare of the horse.