Barley is a whole grain that has been a staple food for centuries. For individuals monitoring carbohydrate intake, the question of its impact on blood sugar is important, especially when managing conditions like diabetes. The way the human body processes the complex carbohydrates in barley determines its overall metabolic effect. This grain contains specific components that distinguish its glycemic response from many other commonly consumed starches.
The Direct Answer: Barley’s Glycemic Impact
Barley generally has a modest effect on blood sugar compared to many refined grains. Scientists quantify this using the Glycemic Index (GI), which ranks foods based on how quickly they raise blood glucose levels. Foods scoring 55 or less are considered low-GI. Whole-grain barley, specifically the hulled variety, is consistently classified in the low-GI range. Boiled whole-grain barley has a remarkably low GI of approximately 21, placing it among the lowest of all staple grains. Even processed pearled barley, which has had some fiber removed, maintains a moderate GI value, often around 58.
The Glycemic Load (GL) offers a more complete picture by factoring in the typical serving size. A low GL is 10 or less. Boiled whole-grain barley typically has a GL of just 9 per standard serving, confirming its mild effect on blood glucose. This contrasts sharply with high-GI staples like white rice, which lead to faster and more pronounced blood sugar spikes.
The Role of Beta-Glucan Fiber
The favorable blood sugar response from barley is directly attributable to beta-glucan, a type of soluble fiber. Barley contains high concentrations of beta-glucan, typically between 4% and 10% by weight. This fiber slows down the body’s processing of the grain’s starches.
When beta-glucan reaches the digestive tract, it absorbs water and forms a thick, viscous gel. This increased viscosity slows the movement of the food mixture through the stomach and intestines. The physical barrier created by this gel limits the access of digestive enzymes to the starch molecules.
By slowing the breakdown of carbohydrates, beta-glucan facilitates a more gradual and sustained release of glucose into the bloodstream. This prevents the sharp spike in blood sugar and the corresponding large insulin release often seen after consuming high-GI foods. The effect is beneficial for maintaining stable energy levels and managing long-term glucose control.
Maximizing Glycemic Control Through Preparation
The way barley is processed and prepared significantly influences its final glycemic impact. The two most common forms are hulled barley and pearled barley. Hulled barley is a true whole grain because only the inedible outer husk is removed, leaving the nutrient-rich bran and germ intact, which retains the highest fiber content and the lowest GI.
Pearled barley is polished to remove the bran layer, which reduces the overall fiber content and slightly elevates the GI, though it offers quicker cooking time. For the best glycemic control, choosing hulled barley or pot barley (which is pearled for a shorter time) is the preferred option due to their higher natural fiber.
A simple preparation technique can further enhance barley’s blood sugar benefits by increasing its resistant starch content. Resistant starch is a carbohydrate that resists digestion in the small intestine, acting much like fiber. When barley is cooked and then cooled, a process called retrogradation occurs, changing the starch structure.
Cooling cooked barley in the refrigerator overnight causes some of the starch to reorganize into this resistant form. This process can significantly reduce the effective carbohydrate load of the meal, resulting in an even smaller blood glucose response when the barley is consumed, even if it is reheated. For portion control, remember that barley expands considerably during cooking.