Red Raspberries and Their Bioactive Polyphenols: Cardiometabolic and Neuronal Health Links

Abstract

Diet is an essential factor that affects the risk of modern-day metabolic diseases, including cardiovascular disease, diabetes mellitus, obesity, and Alzheimer disease. The potential ability of certain foods and their bioactive compounds to reverse or prevent the progression of the pathogenic processes that underlie these diseases has attracted research attention. Red raspberries (Rubus idaeus L.) are unique berries with a rich history and nutrient and bioactive composition. They possess several essential micronutrients, dietary fibers, and polyphenolic components, especially ellagitannins and anthocyanins, the latter of which give them their distinctive red coloring. In vitro and in vivo studies have revealed various mechanisms through which anthocyanins and ellagitannins (via ellagic acid or their urolithin metabolites) and red raspberry extracts (or the entire fruit) could reduce the risk of or reverse metabolically associated pathophysiologies. To our knowledge, few studies in humans are available for evaluation. We review and summarize the available literature that assesses the health-promoting potential of red raspberries and select components in modulating metabolic disease risk, especially cardiovascular disease, diabetes mellitus, obesity, and Alzheimer disease-all of which share critical metabolic, oxidative, and inflammatory links. The body of research is growing and supports a potential role for red raspberries in reducing the risk of metabolically based chronic diseases.

Keywords: anthocyanins; cardiovascular disease; diabetes; ellagic acid; inflammation; oxidative stress; polyphenols; red raspberries.

FIGURE 1

Structures of major polyphenols in red raspberries: anthocyanidins and anthocyanins (A), ellagic acid (B), sanguiin H6 (C), and lambertianin C (D).

FIGURE 2

The physiological consequences of poor diet and obesity promote metabolic, oxidative, and immune system imbalances, resulting in clinically relevant changes that affect peripheral and central processes that over time lead to chronic diseases, such as cardiovascular disease, diabetes mellitus, and Alzheimer disease. Red raspberries and their predominant polyphenols have been studied in a variety of models for their potential direct and indirect effects on chronic disease mechanisms. The growing literature suggests that red raspberry fruit, including various extracts and individual components, have anti-inflammatory, antioxidative, and metabolic-stabilizing activity. These effects are associated with improvements in blood pressure and lipid profiles, decreased atherosclerotic development, improved vascular function, stabilization of uncontrolled diabetic symptoms (e.g., glycemia), and improved functional recovery from brain injury in preclinical models.