Nutrients and botanicals in the treatment of diabetes in veterinary practice - Diabetes In Veterinary Practice

Alternative Medicine Review,  Sept, 2001  by Susan Wynn

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Abstract

Diabetes mellitus can be frustrating to treat in veterinary practice, but botanical and nutritional supplements may offer assistance in stabilizing difficult patients. While dogs are typically subject to type 1 diabetes, cats develop type 2 diabetes as much as 70 percent of the time. Whereas treatment adjuncts to insulin may address carbohydrate metabolism from glucose absorption to insulin receptor function, success may depend on the type of diabetes present in the patient.

(Altern Med Rev 2001;6 (Suppl):S17-S23)

Regulators of Glucose Absorption

Dietary therapy has been and will remain a mainstay of diabetes treatment. Dietary fiber has been shown to reduce glucose absorption from the gut, increasing glycemic control. Insoluble fiber (in the form of 12-percent cellulose incorporated into the diet) was shown to reduce glucose absorption in cats (1) and dogs (2) in randomized, crossover trials. Another study in dogs with insulin-dependent diabetes compared fiber content of several diets and their effect on insulin dosage and blood glucose concentrations. Dogs were randomly assigned either a low-fiber diet, a high insoluble-fiber diet, or a high soluble-fiber diet. While there was no significant difference in insulin requirements among the three groups, the insoluble-fiber diet resulted in significantly lower blood glucose concentrations, compared to the low-fiber and soluble-fiber diets. (3)

On the other hand, another study found soluble fibers, such as guar gum, to offer possible protection for diabetes and hyperlipidemia. Healthy beagles were fed a diet of seven-percent fiber: either guar gum, inulin, or sugar beet fiber. While neither sugar beet fiber nor inulin had a metabolic effect on the dogs, guar gum resulted in decreased postprandial insulin and fasting cholesterol. The researchers concluded that "Guar gum would be a suitable ingredient for dietary therapy of chronic diseases such as diabetes mellitus or hyperlipidemia in the dog." (4) Some of these same researchers found both sugar beet fiber and fructo-oligosaccharides (fermentable fibers) fed to healthy beagles resulted in a significant decrease in triglycerides and postprandial glucose. (5) Sources of soluble fiber are legumes (one of the best), whole grains, vegetables, and fruits -- most of which also contain some insoluble fiber. Insoluble fiber supplementation may be supplied via vegetables and whole grains.

In humans it appears insulin resistance may develop (in part) from a high carbohydrate diet, (6) a theory particularly interesting considering the typical dry diet fed veterinary patients. Cats (obligate carnivores) and dogs (facultative carnivores) may, in fact, have innate insulin resistance mechanisms, making them less tolerant of the highly digestible carbohydrate diets recommended in principle for humans, and provided by typical dry commercial diets. It is well to remember that cats have no requirement for carbohydrates whatsoever; therefore, insulin resistance may have developed in this species as a mechanism for coping with exogenous glucose shortages. It is possible the progression of diabetes is hastened by feeding diabetic cats and dogs a high-carbohydrate dry diet.

While the role of obesity in the development of diabetes is well recognized, the connection between veterinary weight loss diets and obese diabetic pets has not received sufficient attention. The development of insulin resistance is seen particularly in cats, possibly due to a lifetime of dry, high-carbohydrate commercial foods. On the other hand, the overweight (and normal weight) diabetic cat is usually fed a low-fat, free choice, high-carbohydrate weight loss diet. Since many overweight cats return to a non-diabetic state when their weight is normalized, dietary management of these cats is of particular concern. Managing overweight cats is often complicated, as hepatic lipidosis occurs easily and is potentially fatal. A discussion of weight management in these cats is beyond the scope of this paper, but should be undertaken with care.

In any event, the time has come to reevaluate dietary recommendations for the overweight diabetic veterinary patient. To this end, some are feeding a high-quality maintenance diet -- prescription or homemade -- with quality meat protein and lower digestible carbohydrate levels, adding insoluble fibers (vegetables, wheat bran) to take advantage of fiber's effect on glycemic control. This is particularly important when a pet is a so-called "picky" eater or has nutritional needs not covered by a commercial, high-fiber, weight-loss diet (e.g., food allergies, renal failure, etc.). Recently, one pet food manufacturer introduced a low-carbohydrate diet specifically for managing diabetes in cats.

Regulators of Insulin Availability or Release

Botanicals

Gymnema sylvestre is an herb that has been used in Ayurvedic medicine for 2,000 years in treating diabetes. Recent clinical and experimental studies suggest this use is warranted. Numerous case series reports indicate that Gynmema improves glucose tolerance and clinical status in human diabetics. Gymnema extract was shown to increase insulin secretion in pancreatic beta-cell lines by increasing membrane permeability. (7) In streptozocin-treated rats, administration of Gymnema extract was observed to increase serum insulin levels as well as the absolute number of pancreatic islet cells. The same group showed Gymnema improved glucose uptake in target tissues. (8,9) Clinical use suggests Gymnema must be administered for two to three months for maximum effect. Although the herb is available alone, it is more often used in combination with other herbs traditionally used in the treatment of diabetes, including Momordica charantia (bitter melon), fenugreek, and ginseng.