Table 1.
Clinical studies on the effects of berries on glycemia and insulin resistance in healthy adults
| Reference (year) | Participants | Study design | Intervention | Significant findings |
|---|---|---|---|---|
| Stote et al. (2019)26 | Healthy adults sample size: n = 17 | Randomized, placebo-controlled, crossover, 2 h-postprandial study | Standardized high-CHO breakfast with whole blueberries 140 g (Tx1); or calorie, sugars-, and fiber-matched placebo gel devoid of polyphenols (Cx1) | ↑Pancreatic polypeptide concentrations in Tx1 |
| Bell et al. (2017)27 | Healthy young adults sample size: n = 17 | Double-blind, five crossover studies of 2.5 h-postprandial studies | Blueberry powder 34 g beverages with anthocyanin contents 310 mg (Tx1), with sugar-matched variant (Tx2); or blueberry powder 80 g sugar-matched beverage with anthocyanin contents 724 mg (Tx3); or no-added-sugar control beverage (Cx1); or sugar-matched control beverage (Cx2) | Delayed postprandial phase of glucose response in Tx1, Tx2, and Tx3 |
| Törrönen et al. (2013)40 | Healthy adult females sample sizes: n = 13–20 | Three single-blinded, randomized, controlled, crossover 2 h -postprandial studies | Study 1: Strawberry, bilberry, or lingonberry puree 150 g with white bread 50 g (Tx1) or rye bread 50 g (Tx2) Study 2: Raspberry, cloudberry, or chokeberry puree 150 g with white bread 50 g (Tx3) or rye bread 50 g (Tx4) Study 3: Strawberry, bilberry, cranberry, and blackcurrant mixture at 37.5 g per berry with white bread 50 g (Tx5) or rye bread 50 g (Tx6) |
↓Postprandial insulin response in Tx1, Tx3, Tx5, and Tx6 ↑Glycemic profile improvements in Tx5 and Tx6 |
| Törrönen et al. (2012)39 | Healthy adult females sample size: n = 20 | Randomized, controlled, crossover five 2 h-postprandial meal studies | Whole blackcurrant puree 150 g (Tx1); or whole lingonberry puree 150 g (Tx2); or blackcurrant nectar 300 mL with added sucrose 35 g (Tx3); or lingonberry nectar 300 mL with added sucrose 35 g (Tx4); or sucrose 35 g control meal (Cx1) | ↓Insulin, glucose, FFA rebound and ↑glycemic profile improvements in all Tx groups |
| Granfeldt et al. (2011)47 | Healthy young adults sample sizes: n = 9–11 | Two series 2 h-postprandial meal studies | Series 1: Bilberry and fermented oatmeal drink 302 g with reference bread ∼70 g (Tx1); or rose-hip and fermented oatmeal drink 300 g with reference bread ∼70 g (Tx2) | ↓Insulin index in Tx1 |
| Series 2: Bilberry and fermented oatmeal drink 270.3 g with reference bread 70 g (Tx3); or fermented oatmeal drink 270.3 g with reference bread 70 g (Tx4); or bilberry and fermented oatmeal drink 270.3 g with added whole homogenized bilberries 127.5 g and reference bread 70 g (Tx5) | ↑Insulin sensitivity in Tx3 ↓insulin response Tx4 and Tx5 |
CHO: Carbohydrate, Cx: control group, FFA: free fatty acid, Tx: treatment group.