Study: Starch Limitation Key for Short-Term Blood Sugar Control

To better control blood sugar and insulin levels, horse owners are encouraged to limit starch intake in their animals, rather than only supplementing their horse's diet with fats, recommends Ingrid Vervuert, DrMedVet, PhD, and colleagues from the Institute of Animal Nutrition in Leipzig, Germany.

"Controlling post-prandial (post-feeding) sugar and insulin levels is hypothesized to be an important factor in limiting the development of metabolic disorders and insulin resistance," explained Vervuert. "Previous studies have shown that either decreasing starch intake or replacing the starch with fat can avoid post-prandial sugar and insulin surges."

To further evaluate the impact of fat supplementation on sugar and insulin responses in horses, Vervuert and colleagues sequentially fed four horses three different diets:

  • A cracked corn diet (with a starch intake of 2 g/kg);
  • The same diet supplemented with soybean oil (0.2 ml/kg), and;
  • The same diet supplemented with fish oil (0.2 ml/kg).

According to Vervuert, "Unlike previous studies performed in both humans and horses, we found that supplementing a starchy diet with moderate amounts of either soybean or fish oil did not impact glucose or insulin responses."

"That is, the increase in post-prandial blood glucose and insulin levels was similar, regardless of the diet," she continued.

Based on these findings, the authors concluded that limiting the intake of starches is more important for the short-term control of sugar and insulin levels than supplementing the diet with fats.

"Further research on the effect of long-term supplementation with fats, particularly fish oil, in horses to improve insulin sensitivity is needed, considering the increased recognition of the importance of insulin resistance and metabolic syndrome in the equine industry," said Vervuert.

The study, "Short-term effects of a moderate fish oil or soybean oil supplementation on postprandial glucose and insulin responses in healthy horses," is scheduled to be published in an upcoming edition of The Veterinary Journal. The abstract is currently available on PubMed.  

About the Author

Stacey Oke, DVM, MSc

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More