People with type-II diabetes who drank the fermented tea drink kombucha for four weeks had lower fasting blood glucose levels compared to when they consumed a similar-tasting placebo beverage, according to results from a clinical trial conducted by researchers at Georgetown University’s School of Health, the University of Nebraska-Lincoln and MedStar Health. This finding, from a pilot 12-person feasibility trial, points to the potential for a dietary intervention that could help lower blood sugar levels in people with diabetes and also establishes the basis for a larger trial to confirm and expand upon these results.

This finding was reported in Frontiers in Nutrition on August 1, 2023.

Kombucha is a tea fermented with bacteria and yeasts and was consumed as early as 200 B.C. in China, but it did not become popular in the U.S. until the 1990s. Its popularity has been bolstered by anecdotal claims of improved immunity and energy and reductions in food cravings and inflammation, but proof of these benefits has been limited.

“Some laboratory and rodent studies of kombucha have shown promise and one small study in people without diabetes showed kombucha lowered blood sugar, but to our knowledge this is the first clinical trial examining effects of kombucha in people with diabetes,” says study author Dan Merenstein, M.D., professor of Human Sciences in Georgetown’s School of Health and professor of family medicine at Georgetown University School of Medicine. “A lot more research needs to be done but this is very promising.”

Merenstein continued, “A strength of our trial was that we didn’t tell people what to eat because we used a crossover design that limited the effects of any variability in a person’s diet.”

The crossover design had one group of people drinking about eight ounces of kombucha or placebo beverage daily for four weeks and then after a two-month period to ‘wash out’ the biological effects of the beverages, the kombucha and placebo were swapped between groups with another four weeks of drinking the beverages. Neither group was told which drink they were receiving at the time.

Kombucha appeared to lower average fasting blood glucose levels after four weeks from 164 to 116 milligrams per deciliter while the difference after four weeks with the placebo was not statistically significant. Guidelines from the American Diabetes Association recommended blood sugar levels before meals should be between 70 to 130 milligrams per deciliter.

The researchers also looked at the makeup of fermenting micro-organisms in kombucha to determine which ingredients might be the most active. They found that the beverage was mainly comprised of lactic acid bacteria, acetic acid bacteria, and a form of yeast called Dekkera, with each microbe present in about equal measure; the finding was confirmed with RNA gene sequencing.

The kombucha used in this study was produced by Craft Kombucha, a commercial manufacturer in the Washington, DC, area. It has been re-branded as Brindle Boxer Kombucha.

“Different studies of different brands of kombucha by different manufacturers reveal slightly different microbial mixtures and abundances,” says Robert Hutkins, Ph.D., University of Nebraska-Lincoln and the study’s senior author. “However, the major bacteria and yeasts are highly reproducible and likely to be functionally similar between brands and batches, which was reassuring for our trial.”

“An estimated 96 million Americans have pre-diabetes — and diabetes itself is the eighth leading cause of death in the U.S. as well as being a major risk factor for heart disease, stroke and kidney failure,” says Chagai Mendelson, M.D., lead author who was working in Merenstein’s lab at Georgetown while completing his residency at MedStar Health. “We were able to provide preliminary evidence that a common drink could have an effect on diabetes. We hope that a much larger trial, using the lessons we learned in this trial, could be undertaken to give a more definitive answer to the effectiveness of kombucha in reducing blood glucose levels, and hence prevent or help treat type-II diabetes.”

Eating healthy is a priority for many people but knowing where to start and with what foods may be a little trickier. One way to level up the nutritional value of your meals is to better understand whole grains and why they are important for a heart-healthy diet.

As a key feature of heart-healthy diets, whole grains like sorghum, oatmeal and brown rice are rich sources of dietary fiber, may improve blood cholesterol levels and provide nutrients that help the body form new cells, regulate the thyroid and maintain a healthy immune system.

However, according to a survey by The Harris Poll on behalf of the American Heart Association, U.S. adults are least knowledgeable about refined vs. whole grains compared to other foods like fruits, vegetables and proteins. Also, when asked to identify whole grains and refined grains, most adults incorrectly believe multi-grain bread is a whole grain and only 17% believe sorghum is an example of a whole grain when it is, in fact, a nutritious whole-grain option.

If you’re looking to try more whole grains, sorghum is a primary ingredient in these heart-healthy recipes for Pancakes with Blueberry Vanilla Sauce, Raspberry Streusel Muffins and Garden Vegetable Stir-Fried Sorghum. These flavorful dishes can be part of an overall healthy diet as recommended by the American Heart Association’s Healthy for Good initiative, supported by the Sorghum Checkoff.

Find more heart-healthy meal ideas at Heart.org/healthyforgood.

Raspberry Streusel Muffins
Recipe courtesy of the American Heart Association and Sorghum Checkoff
Servings: 12 (1 muffin per serving)

Muffins:
            Nonstick cooking spray
1 1/2    cups whole grain sorghum flour
1          teaspoon ground cinnamon
3/4       teaspoon baking soda
3/4       cup low-fat buttermilk
1/3       cup firmly packed light brown sugar
3          large egg whites
1/4       cup canola or corn oil
2          teaspoons grated lemon zest
1          teaspoon vanilla extract
1          cup fresh or frozen unsweetened raspberries, thawed if frozen

Streusel:
2          tablespoons whole grain sorghum flour
2          tablespoons light brown sugar
2          tablespoons uncooked quick-cooking rolled oats
2          tablespoons chopped pecans
2          tablespoons light tub margarine
1/2       teaspoon ground cinnamon

To make muffins: Preheat oven to 400 F. Lightly spray 12-cup muffin pan with nonstick cooking spray.

In large bowl, stir sorghum flour, cinnamon and baking soda.

In medium bowl, whisk buttermilk, brown sugar, egg whites, oil, lemon zest and vanilla. Stir into flour mixture until batter is just moistened and no flour is visible without overmixing. Spoon batter into muffin cups. Top each muffin with raspberries.

To make streusel: In small bowl, stir sorghum flour, brown sugar, oats, pecans, margarine and cinnamon to reach texture of coarse crumbs. Sprinkle over muffins, gently pushing into batter. Bake 16 minutes, or until wooden toothpick inserted in center comes out clean. The USDA recommends cooking egg dishes to 160 F.

Transfer pan to cooling rack. Let stand 5 minutes. Carefully transfer muffins to rack. Let cool completely, about 20 minutes.

Garden Vegetable Stir-Fried Sorghum
Recipe courtesy of the American Heart Association and Sorghum Checkoff
Servings: 4 (1 1/2 cups per serving)

1          cup uncooked whole-grain sorghum
2          teaspoons toasted sesame oil
2          medium garlic cloves, minced
1          teaspoon gingerroot, peeled and minced                   
1          cup fresh or frozen broccoli florets, chopped, thawed if frozen
1          cup snow peas, trimmed and halved   
1/2       cup carrot strips, sliced into matchsticks
1/2       cup red bell pepper, diced
1/2       cup button mushrooms, thinly sliced
1/2       cup frozen shelled edamame, thawed
2          large eggs
2          tablespoons low-sodium soy sauce, divided
1/2       cup water chestnuts, rinsed and drained
1/4       cup green onions, diagonally sliced

Prepare sorghum using package directions, omitting salt. Once cooked, spread sorghum in even layer on rimmed baking sheet or 13-by-9-by-2-inch baking dish. Let stand 5-10 minutes at room temperature. Refrigerate, uncovered, 20 minutes, or until cool.

In large nonstick skillet over medium heat, heat oil, swirling to coat bottom. Cook garlic and gingerroot 30 seconds, stirring frequently. Increase heat to medium-high. Cook broccoli, snow peas, carrots, bell pepper, mushrooms and edamame 10-12 minutes, or until vegetables are tender-crisp, stirring frequently.

In small bowl, using fork, beat eggs and 1 tablespoon soy sauce.

Reduce heat to medium. Stir water chestnuts and sorghum into vegetable mixture. Push mixture to sides of skillet. Pour egg mixture into center of skillet. Using heatproof rubber scraper, stir 1-2 minutes, or until partially set.

Stir vegetable mixture into partially cooked egg mixture. Cook 1 minute, or until eggs are cooked through and sorghum is heated through, stirring constantly. The USDA recommends cooking egg dishes to 160 F.

Remove from heat. Stir in remaining soy sauce. Sprinkle with green onions.

Pancakes with Blueberry Vanilla Sauce
Recipe courtesy of the American Heart Association and Sorghum Checkoff
Servings: 4 (2 pancakes, 1/4 cup sauce and 2 tablespoons yogurt per serving)

Sauce:
2          teaspoons cornstarch
1/3       cup water
1          cup blueberries
1          tablespoon sugar
1 1/2    teaspoons vanilla extract

Pancakes:
1/2       cup quick-cooking rolled oats
1/2       cup whole grain sorghum flour
1 1/2    tablespoons firmly packed light brown sugar
1 1/2    teaspoons baking powder
1/2       teaspoon ground cinnamon
1/2       cup fat-free milk
1/2       cup unsweetened applesauce
1          large egg
1          tablespoon canola or corn oil

Topping:
1/2       cup fat-free plain Greek yogurt

To make sauce: Put cornstarch in medium saucepan. Add water, stirring to dissolve. Stir in blueberries and sugar. Bring to boil over medium-high heat. Boil 1-2 minutes, or until sauce thickens slightly. Remove from heat. Stir in vanilla. Cover to keep warm. Set aside.

To make pancakes: In medium bowl, stir oats, sorghum flour, brown sugar, baking powder and cinnamon.

In small bowl, whisk milk, applesauce, egg and oil. Stir into flour mixture until batter is just moistened and no flour is visible without overmixing.

Heat nonstick griddle over medium heat. Test temperature by sprinkling drops of water on griddle. Griddle is ready when water evaporates quickly.

Pour 1/4 cup batter for each pancake on griddle. Cook 2-3 minutes, or until tiny bubbles appear on surface and bottoms are golden brown. Flip pancakes. Cook 1-2 minutes, or until cooked through and golden brown on bottoms. The USDA recommends cooking egg dishes to 160 F. 

Transfer pancakes to plates. Spoon sauce over pancakes. Top each serving with 2 tablespoons yogurt.

Summertime celebrations with friends, family and neighbors are a perfect way to enjoy the sunshine, warm weather and camaraderie. To satisfy a hungry crowd, though, you’ll need recipes fit for the occasion.

Turn to a versatile signature ingredient like Grapes from California, which can be used in dishes of all kinds from refreshing salads and entrees to flavorful condiments and sweet desserts. Grapes are crisp, juicy and sweet, making them a fantastic addition of flavor and texture for a wide range of recipes. Whether fresh, sauteed, roasted, grilled or even pickled, grapes make it easy to take meals to the next level.

For example, you can start the festivities with grapes as an easy, portable and healthy snack perfect for summer days or use them as a juicy addition to this all-in-one Honey-Lime Quinoa and Grape Salad that’s ideal as a light appetizer or a meal all on its own. Follow it up (or pair it) with a summertime staple – hot dogs – given a sweet-tart twist from pickled grape relish that takes these Sweet and Tangy Pickled Grape Hot Dogs to new heights.

Dessert can’t be much easier than Creamy Vegan Grape Ice Cream as a dairy-free alternative to traditional summer sweets. Oat coffee creamer and pureed grapes are all you need to create this delicious frozen treat. Simply freezing whole grapes also makes for an easy and healthy frozen dessert.

Visit GrapesFromCalifornia.com to discover more summer entertaining inspiration.

Honey-Lime Quinoa and Grape Salad
Prep time: 15 minutes, plus at least 1 hour chill time
Cook time: 22 minutes          
Servings: 6 (1 1/3 cups per serving)

Lime Vinaigrette:
1/2       cup extra-virgin olive oil
1/3       cup lime juice
2          tablespoons honey
3/4       teaspoon sea salt
            freshly ground pepper, to taste

Salad:
1 1/2    cups quinoa
2          cups vegetable broth
2          cups halved Grapes from California
1/2       cup minced red onion
1/4       cup chopped fresh cilantro
2          tablespoons minced jalapeno pepper
1          large firm, ripe avocado, peeled, pitted and cut into bite-size pieces
1/2       cup chopped peanuts (optional)

To make lime vinaigrette: In medium bowl, whisk olive oil, lime juice, honey, sea salt and pepper, to taste.

To make salad: In fine mesh strainer, rinse quinoa; drain well. In medium saucepan, bring broth and quinoa to boil; reduce heat and simmer, covered, 12 minutes. Remove from heat and let stand 10 minutes then fluff with fork and let cool. Transfer to large bowl.

Pour vinaigrette over quinoa; stir well to coat. Add grapes, onion, cilantro and jalapeno pepper; cover and chill at least 1 hour.

Lightly stir in avocado and transfer to decorative bowl. Sprinkle with nuts, if desired.

Notes: Salad may be prepared and refrigerated up to 2 days ahead without avocado and peanuts. Add avocado and peanuts just before serving.

Nutritional information per serving: 520 calories; 10 g protein; 52 g carbohydrates; 32 g fat (55% calories from fat); 4 1/2 g saturated fat (8% calories from saturated fat); 0 mg cholesterol; 490 mg sodium; 7 g fiber.

Sweet and Tangy Pickled Grape Dogs
Prep time: 15 minutes, plus 1 hour marinating time
Cook time: 5 minutes
Servings: 8 (1/4 cup relish per serving)

1/2       teaspoon mustard seeds
1/2       teaspoon coriander seeds
1/2       teaspoon black peppercorns
1/2       cup wine vinegar
1/4       cup packed brown sugar
2 1/4    cups quartered or coarsely chopped Grapes from California (red, green, black or combination)
1/4       cup thinly sliced red onion
8          turkey or chicken hot dogs
8          hot dog buns, lightly toasted

Place mustard seeds, coriander seeds and black peppercorns in small resealable bag. Using meat mallet or rolling pin, crush seeds and peppercorns.

In small saucepan, stir vinegar, sugar, seeds and peppercorns; bring to boil. Remove from heat and stir to dissolve sugar; let cool. Stir in grapes and onion; set aside to cool and marinate 1 hour, stirring occasionally.

Heat grill to medium heat.

Grill hot dogs 5 minutes, turning occasionally, or until charred and heated through.

Place hot dogs in buns. Using slotted spoon, top with pickled grapes.

Nutritional information per serving: 280 calories; 10 g protein; 39 g carbohydrates; 10 g fat (32% calories from fat); 2 g saturated fat (6% calories from saturated fat); 35 mg cholesterol; 630 mg sodium; 1 g fiber.

Creamy Vegan Grape Ice Cream
Prep time: 20 minutes
Cook time: 10-15 minutes
Servings: 8 (1/2 cup per serving)

1          pound stemmed black Grapes from California
12        ounces vanilla oat coffee creamer, well chilled
12        ounces unsweetened oat coffee creamer, well chilled

In high-speed blender, puree grapes until smooth. Transfer to medium saucepan and bring to simmer. Reduce heat to low and cook 10-15 minutes, or until reduced to 1 cup. Cover and refrigerate until well chilled.

Stir creamer into pureed grapes and pour into bowl of ice cream maker. Freeze according to manufacturer’s directions. Transfer to freezer-safe container; cover and freeze until firm.

Substitution: For lighter color, use 3/4 pound black grapes and 1/4 pound red.

Note: Make sure ice cream maker bowl is well chilled or frozen before making ice cream.

Nutritional information per serving: 140 calories; 0 g protein; 22 g carbohydrates; 6 g fat (39% calories from fat); 0 g saturated fat; 0 mg cholesterol; 45 mg sodium; 1 g fiber.