Natural Carbohydrate Absorption Inhibitors

There are also natural medicines that lower blood glucose levels by decreasing or slowing absorption of carbohydrates in the gut, although they work using a different mechanism. Most of these types of natural medicines are fiber based. Examples include:

Blond psyllium (Plantago ovata) seed

This substance is used in Metamucil, Fiberall, Konsyl, and other fiber products. Several small-scale clinical trials show that consuming blond psyllium lowers postprandial blood glucose concentrations by 14% to 20%. Best results seem to occur when psyllium is taken with a meal. Psyllium also has the added benefit of reducing total and low-density lipoprotein (LDL) cholesterol in diabetes patients.

Glucomannan (Amorphophallus konjac).

Glucomannan is an insoluble polysaccharide from the tubers of a plant called konjac. Glucomannan has shown that it can delay glucose absorption. When taken daily at doses between 3.6 grams and 7.2 grams for 90 days, it can reduce mean fasting glucose levels by 29% and lead to decreases in the dose of insulin or oral hypoglycemics needed to control blood sugar. Glucomannan can also reduce serum cholesterol and improve glucose tolerance and lipid profiles in people with diabetes.

Guar gum (Cyamopsis tetragonoloba).

Guar gum is a soluble fiber from the guar plant. Small clinical trials show that it reduces fasting and postprandial blood glucose levels in patients with both type 1 and type 2 diabetes.

Oat bran (Avena sativa).

Oat bran is high in beta-glucan, which is a soluble fiber. Consuming oat bran as part of the diet can significantly reduce blood glucose levels.

Soy (Glycine max).

Some researchers believe soy is beneficial for diabetes because of the fiber contained in soy, however there is other research that point to other mechanisms, including a direct effect of soy isoflavones. Postmenopausal women with type 2 diabetes who take soy protein 30 grams/day (providing 132 mg isoflavones) seem to have decreased insulin resistance, lower fasting blood glucose, and lower HbA1c. Other preliminary evidence shows that an extract of a fermented soy product called touchi acts as an alpha-glucosidase inhibitor. It modestly lowers blood glucose, HbA1c, and triglycerides in type 2 diabetes patients.