The #1 Whole Grain to Eat to Decrease High Blood Sugar, Recommended by a Dietitian

It can feel like there are a lot of rules when it comes to managing a chronic disease like high blood pressure or diabetes. A common misconception about diabetes is that you should be avoiding all carbs. While carbs do raise your blood sugar levels, not all foods with carbs affect the body the same way. In fact, experts agree that you can (and should) eat carbs when you have diabetes. 

Your blood sugar naturally rises and falls as you eat meals and snacks throughout the day. Digestion breaks down the carbs in your food into glucose—the body’s primary energy source. When glucose enters the bloodstream, your body responds by making insulin so that the glucose can enter cells for energy use. But when a person has diabetes, this process is disrupted, and blood sugar levels rise above a healthy level.

Carbohydrate foods' unique sugar, starch and fiber content drives your body’s response. Refined carbs (think baked goods, pasta and white bread) are generally lower in fiber and higher in sugar. Since they are easily digested, glucose rushes into your bloodstream. Eating a lot of refined carbohydrates can send your blood sugar on a roller coaster and can lead to dangerous diabetes complications over time. On the other hand, complex carbohydrates like whole grains, fruits, vegetables and legumes have the opposite effect. Thanks to their fiber content, digestion takes longer, so glucose enters the bloodstream gradually rather than all at once. 

Rather than avoiding all carbs to keep your blood sugar in check, a smarter approach is to focus on including high-fiber carbs in your meals throughout the day. Read on to find out our favorite whole grain for lowering blood sugars. 

What’s the Relationship Between Whole Grains and Diabetes?

A “whole” grain still contains all the parts of the plant—the bran, germ and endosperm. By consuming the grain whole, you reap the benefits of all the nutrients packed inside, like fiber, antioxidants, B vitamins and healthy fats. This combination of nutrients makes whole grains such a boon for disease prevention. In fact, a large study from 2020 published in the British Medical Journal that included data from almost 200,000 individuals found that people who ate whole grains had a 29% lower risk of developing diabetes than those who rarely ate them. 

If whole grains can lower your risk of developing diabetes, can they also help you manage your blood sugar? We think so. A 2020 analysis of over 20 studies published in the Journal of the Academy of Nutrition and Dietetics noted that replacing refined grains with whole grains could significantly lower hemoglobin A1C (a measure of blood sugar). 

Plus, the digestion-slowing effects of fiber aren’t the only reason whole grains are a blood sugar superhero. A small 2019 study from Molecular Nutrition & Food Research found that when participants were eating a whole-grains-based diet, their beta cell function (the cells that secrete insulin) was better than when they were on the refined-grain diet. When more insulin is available, your cells have more access to the glucose in your bloodstream for energy. 

Have we convinced you to start adding whole grains to your plate yet? While all whole grains can be enjoyed when living with diabetes, our top pick for lowering high blood sugar is barley—here’s why.

Why Barley Is Great for Lowering High Blood Sugar

Barley has a similar nutrition profile to oats, which research shows may help manage your weight, lower blood pressure and improve blood sugar. Pearled barley has been partially refined, so choose whole-grain barley when possible since it will digest more slowly. 

According to the USDA, 1 cup (157 grams) of cooked pearled barley provides:

• Calories: 193
• Total carbohydrates: 44g
• Dietary fiber: 6g
• Added sugar: 0g
• Protein: 4g
• Total fat: <1g
• Saturated fat: 0g
• Cholesterol: 0mg
• Sodium: 5mg
• Potassium: 146 mg
• Phosphorus: 85mg
• Magnesium: 35mg

Researchers have seen positive improvements in blood sugar by replacing just a portion of the refined grains on your plate with barley. For example, a 2019 study, published in Clinical Nutrition Research, with people without diabetes found that replacing half of a serving of white rice with barley improved post-meal blood glucose and 24-hour glucose control versus consuming the white rice alone. A second study from 2022 published in Diabetology International that included individuals with diabetes found similar results: mixing barley with white rice improved post-meal blood sugar levels. So, if the thought of saying goodbye to your favorite white pasta and bread forever is unsustainable for you, you might not have to go 100% on whole grains. You can always mix a whole grain with a refined one. 

Rich in Soluble Fiber

There are two types of dietary fiber—soluble and insoluble—and barley offers both. Soluble fiber is particularly beneficial for blood sugar management. According to a 2020 review in Nutrients, soluble fiber helps lower blood sugar in two ways: 1) by forming a thick gel in the digestive tract so less glucose can be absorbed, and 2) by slowing down digestion, preventing spikes in blood sugar. 

Beta-glucan is a type of soluble fiber that has been well-studied for its health benefits. Although oats get all the attention for their beta-glucan content, barley contains just as much of this fabulous fiber. A 2021 intervention trial published in the Journal of Functional Foods found that consuming just 5 grams of beta-glucan daily for 12 weeks was enough to significantly improve hemoglobin A1C.

Source of Antioxidants

Chronic inflammation and diabetes have a complicated relationship. There’s evidence that chronic inflammation can increase one's risk of developing diabetes, but on the flip side, inflammation is also a complication of diabetes. Incorporating foods rich in antioxidants (like whole grains) can help neutralize the free radicals to blame for chronic inflammation. Barley is rich in phytochemicals like phenolic acid, flavonoids, phytosterols and tocols (a form of vitamin E), all of which fight oxidative stress, per a 2020 article from Nutrients. 

Versatile

Barley is a budget-friendly pantry staple that can be used in a variety of dishes, from soups to salads. Amp up the fiber content of your soup by combining barley with beans—this  Bean & Barley Soup has a whopping 12 grams of fiber per serving. You can also incorporate more fiber into classic soup recipes by swapping noodles for barley; try our Instant Pot Chicken Soup with Root Vegetables & Barley. This grain’s chewy texture and mild flavor also make it a great option for grain-based salads like our Roasted Beet & Barley Salad.

The Bottom Line

Carbs don’t have to be the bad guy when you have diabetes. In fact, they can help you manage your condition. Working closely with your health care provider and dietitian can help determine how many carbs you should eat daily. Prioritizing fiber-rich carbohydrates like fruits, vegetables, whole grains and legumes is a solid strategy for lowering blood sugars. Whole grains, like barley, are not only packed with fiber but also offer essential nutrients that support optimal blood sugar control and overall health.