Chapter 10: The Role of Berry Bioactive Compounds in Diabetes Mellitus

Over 90% of cases of diabetes mellitus (DM) are type 2 (T2DM), the preventable form caused by peripheral insulin resistance and progressive pancreatic β-cell insufficiency. Two key modifiable risk factors for T2DM are physical inactivity and a Western-style diet with excessive calories, dietary fat, and processed foods. Dietary modification is critical to preventing, delaying, and treating the disease. Specifically, the American Diabetes Association recommends eating more plant-based foods that are rich in complex carbohydrates, fiber, and antioxidant vitamins and minerals. Dietary berries are a promising addition to the diet because they contain these nutrients and are especially rich in health-promoting bioactive phytochemicals, the most notable of which are flavonoids. This chapter introduces readers to DM and provides a review of the last 20 years of observational and clinical studies on the relationship between the intake of dietary berries and T2DM risk and outcomes in humans. The data indicate that dietary berry intake is associated with a lower risk of T2DM and that long-term berry supplementation has improved glycemia, lipidemia, and biomarkers of oxidative stress and inflammation in adults with T2DM. Additionally, acute berry supplementation has reduced post-prandial glycemia, oxidative stress, and inflammation in people with diabetes. Therefore, the data support recommending dietary berries to prevent, delay, and treat T2DM.