Blueberries’ Impact on Insulin Resistance and Glucose Intolerance

Abstract

Blueberries are a rich source of polyphenols, which include anthocyanin bioactive compounds. Epidemiological evidence indicates that incorporating blueberries into the diet may lower the risk of developing type 2 diabetes (T2DM). These findings are supported by pre-clinical and clinical studies that have shown improvements in insulin resistance (i.e., increased insulin sensitivity) after obese and insulin-resistant rodents or humans consumed blueberries. Insulin resistance was assessed by homeostatic model assessment-estimated insulin resistance (HOMA-IR), insulin tolerance tests, and hyperinsulinemic-euglycemic clamps. Additionally, the improvements in glucose tolerance after blueberry consumption were assessed by glucose tolerance tests. However, firm conclusions regarding the anti-diabetic effect of blueberries cannot be drawn due to the small number of existing clinical studies. Although the current evidence is promising, more long-term, randomized, and placebo-controlled trials are needed to establish the role of blueberries in preventing or delaying T2DM.

Beneficial effects of Aronia melanocarpa berry extract on hepatic insulin resistance in type 2 diabetes mellitus rats

“…Previous studies have shown that consumption of polyphenol compounds from berries has a hypoglycemic effect (Stull, 2016; Vendrame, Del Bo, Ciappellano, Riso, & Klimis‐Zacas, 2016). A. melanocarpa contains high levels of polyphenol compounds, including anthocyanins, proanthocyanidins, flavonoids, and phenolic acid, which have therapeutic properties against diabetes (Sidor, Drożdżyńska, & Gramza‐Michałowska, 2019).…”

Antioxidant, antihyperglycemic, and antidyslipidemic effects of Brazilian-native fruit extracts in an animal model of insulin resistance

“…The total phenolic and flavonoid contents of small fruits, such as blackberries, blueberries, and strawberries, are 100-820 and 14-290 mg/100 g, respectively [24]. These compounds may have various antidiabetic effects such as modification of glucagon-like peptide-1 (GLP-1), alteration of peroxisome proliferator-activated receptor (PPAR) activities, protection against glucolipotoxicity, and modification of endogenous antioxidants [25]. Khoo and collaborators [26] demonstrated that an extract of Canarium odontophyllum, a fruit rich in anthocyanins, inhibited oxidative stress, further inhibited binding of low-density lipoprotein to endothelial cells, and showed protective effect against lipid peroxidation.…”

“…In addition, anthocyanins have been reported to enhance the endogenous antioxidant defense system [25]. The purified anthocyanin C3G increased glutathione (i.e.…”

Protective Effects of Anthocyanins in Obesity‐Associated Inflammation and Changes in Gut Microbiome

“…Among these, anthocyanin‐rich foods have attracted significant attention due to their popularity among commonly consumable food worldwide and have appeared as a promising therapeutic tool for obesity and metabolic diseases, with minimal reported side effects . Anthocyanins belong to a class of polyphenolic compounds called flavonoids, and regulate cellular signaling pathways and modulate numerous health conditions . Studies have demonstrated improvements in adipose tissue inflammation after consumption of anthocyanins in humans and animal models of obesity .…”

“…[11] Anthocyanins belong to a class of polyphenolic compounds called flavonoids, [12] and regulate cellular signaling pathways and modulate numerous health conditions. [13,14] Studies have demonstrated improvements in adipose tissue inflammation after consumption of anthocyanins in humans and animal models of obesity. [15][16][17][18] Moreover, in vitro studies using various cell models have also confirmed anti-inflammatory and lipid metabolizing effects of anthocyanins.…”