Sugar Promotes Chronic Inflammation in Horses

by Juliet M. Getty, Ph.D.

Inflammation. The very word triggers images of pain, redness and swelling. But in the case of injury or infection, acute inflammation is actually a beneficial means of restoring the body to health. Specific cells are called into action to remove the source of injury or infection and repair damaged tissue. It’s when inflammation becomes chronic that areas of the body may lose function.

Any part of the body can be impacted by inflammation, including joints, feet, lungs, muscles, skin, digestive tract, reproductive function, heart, nervous system, pancreas, liver, as well as the hypothalamic brain centers responsible for releasing dopamine and recognizing leptin.

This article focuses on the inflammatory impact that sugar has on your horse’s health. There are several other causes of inflammation, such as stress and obesity, high dietary levels of linoleic acid (an omega 6), free-radical consumption from poorly stored fatty feeds, and trans fat (partially hydrogenated oils); however, the damaging impact of high sugar/high starch diets is commonplace. Sweet feeds and diets high in cereal grains (e.g., oats, barley, corn, wheat, rice, and millet) can lead to health problems over time. Research suggests that this type of diet actually promotes high blood concentrations of pro-inflammatory molecules known as cytokines.

Cytokines can be problematic

Two cytokines in particular, known as interleukin (IL)-1β and IL-6, are stimulated by insulin secretion in response to elevated blood glucose from sugar and starch digestion. Furthermore, overconsumption of oats or other starchy feed, beyond what is digested in the small intestine, can result in hindgut microbial fermentation to organic acids, lowering the cecal pH, and increasing blood lipopolysaccharide (LPS). Elevated LPS induces insulin resistance and increases proinflammatory cytokines.[iii] These scenarios start a cycle of whole-body, low-grade chronic inflammation that further exacerbates insulin resistance. Even the healthy horse may develop endocrine-related disorders as he ages.

In addition to cytokines, hyperglycemia (high blood glucose) also causes the body to generate inflammatory free radicals. These highly volatile, destructive molecules can overwhelm the horse’s antioxidant defenses, alter DNA, accelerate aging, and lead to diseases throughout the body, including the cell’s lessened sensitivity to key hormones.