Fiber and Polyphenols May Improve Post-Prandial Insulin Response
Eating a lot of foods with a high glycemic index has been linked to an increased risk of cardiovascular disease, type-2 diabetes, metabolic syndrome, stroke, and depression. A recent study suggests that consuming more polyphenol and fiber-rich foods in the form of dried fruit and green tea may delay glucose absorption and lower the glycemic index of some foods.
Participants in the study included 22 people. They all consumed four meals: two control meals, one test meal with a low dose of polyphenol and fiber-rich foods and one test meal with a high dose of polyphenol and fiber-rich foods. All of the meals contained 109 g of white bread with 50 g available carbohydrate. The polyphenol and fiber-rich ingredients used in the study included alpha-glucosidase inhibitor from green tea, alpha-anylase inhibitors from green tea, blackberry, blackcurrant, and strawberry, and glucose transport inhibitors from apple peel and strawberry.
The higher dose meal included 1 gram of green tea powder in 200 ml of water as well as 20 g each of apple peel, blackberry, blackcurrant, and strawberry freeze-dried powders mixed with water in order to make a paste that was spreadable on bread.
The lower dose meal had the same ingredients but half the amounts of fruits and green tea, including half the amounts of balancing sugars, dissolved in 200 ml of water in order to equalize the amount of sugars in all of the doses.
The control meal included 0.8 g of sucrose, 5.4 g of glucose, and 8.6 g of fructose dissolved in 200 ml of water.
The researchers found that both test meals resulted in significant dose-dependent decreases on post-prandial glucose and insulin response. There were no significant differences in glucose reduction between the high and low dose meals.
Researchers from the University of Leeds conducted the study. it was published in the August 2016 issue of the British Journal of Nutrition.
Polyphenol intake has been linked with a variety of health benefits, including helping with weight management, fighting certain cancers, and reducing inflammation. Polyphenols can be found naturally in many foods, including honey, a variety of fruits and vegetables, red wine, chocolate, tea, certain oils and many types of grain.
Previous studies have linked fiber consumption with lowering total and LDL cholesterol, and regulating blood sugar for people with diabetes There are two type of fiber: soluble and insoluble. Soluble fiber can be found naturally in oats, peas, beans, apples, citrus fruits, carrots, barley and psyllium. Insoluble fiber can be found in whole wheat and grains, brown rice, fruit, broccoli, cabbage and dark leafy vegetables.