Anthocyanins have gained significant popularity in recent years for their diverse health benefits, yet their limited bioavailability poses a challenge. To address this concern, technologies have emerged to enhance anthocyanin concentration, often isolating these compounds from other food constituents. However, the extent to which isolated anthocyanins confer health benefits compared to their whole-food counterparts remains unclear. This review explores the current literature on anthocyanin bioavailability and metabolism in the body, with a focus on comparing bioavailability when consumed as extracts versus whole foods rich in anthocyanins, drawing from in vitro, in vivo, and human clinical studies. While direct comparisons between anthocyanin bioavailability in whole foods versus isolates are scarce, prevailing evidence favours whole-food consumption over anthocyanin extracts. Further clinical investigations, preferably with direct comparisons, are needed to validate these findings and elucidate the nuanced interplay between anthocyanins and food matrices, informing future research directions and practical recommendations.

Polyphenols, particularly anthocyanins, are associated with metabolic health benefits; however, whether anthocyanin extracts provide greater bioaccessibility than whole foods remain unclear. This study investigated the role of the food matrix in açaí berry, one of the richest natural sources of anthocyanins, by comparing polyphenol and anthocyanin bioaccessibility across freeze-dried whole fruit, crude extract, and purified extract. All samples underwent standardised INFOGEST in vitro digestion, and total polyphenol content (TPC), anthocyanins (ACN), and antioxidant activity were quantified using Folin–Ciocalteu, pH-differential, and DPPH assays, respectively. Intestinal-phase TPC % bioaccessibility was similar in whole fruit (58%) and crude extract (58%) but significantly lower in pure extract (43%). ACN bioaccessibility showed a pronounced matrix effect, with the highest retention in whole fruit (44%), followed by crude extract (32%), and the lowest retention in pure extract (12%). Antioxidant activity after intestinal digestion mirrored these patterns. Overall, these findings demonstrate that the natural açaí food matrix substantially preserves anthocyanin stability during digestion, resulting in higher bioaccessible levels than matrix-free extracts, suggesting that incorporating matrix components into anthocyanin-rich nutraceuticals may help support greater functional recovery during gastrointestinal digestion.

Pancreatic β-cell dysfunction is the key driver of type 2 diabetes, and anthocyanins have been proposed as dietary compounds that may help preserve β-cell health. This systematic review aimed to synthesise evidence on the direct effects of anthocyanins on β-cell viability, apoptosis, oxidative stress, and insulin secretion across in vitro models. Four databases were searched in March–April 2025, and eighteen studies met the inclusion criteria. Purified anthocyanins—including cyanidin-3-glucoside (C3G), cyanidin-3-rutinoside (C3R), malvidin-3-glucoside (M3G), and delphinidin-3-glucoside (D3G)—as well as anthocyanin-rich berry extracts, were tested in INS-1, MIN6, RIN-m5F cells and primary mouse or human islets under glucotoxic, lipotoxic, oxidative, cytokine, and amyloidogenic stress. Anthocyanins consistently improved β-cell viability, reduced apoptosis, and lowered reactive oxygen species (ROS), nitric oxide (NO), and thiobarbituric acid reactive substances (TBARSs) levels while enhancing antioxidant enzyme activities. Multiple studies showed upregulation of insulin secretion-related genes and proteins, and both acute and chronic treatments increased glucose-stimulated insulin secretion under normal and stressed conditions. Mechanistic pathways involved modulation of mitogen-activated protein kinase (MAPK) signalling, endoplasmic reticulum (ER) stress responses, inflammatory mediators, and mitophagy (PINK1/PARKIN). While effective in vitro concentrations were higher than typical circulating levels, the collective evidence highlights anthocyanins as promising β-cell protective agents and underscores the need for studies examining their metabolites and physiologically relevant exposure.

Amid growing consumer interest in the health benefits of anthocyanins, the market for anthocyanin-based dietary supplements has expanded substantially. However, data on product composition and health claims in the Australian online market remains limited. This study characterises anthocyanin-based dietary supplements available online in Australia (July–August 2024), examining product origin, botanical sources, formulation, extract concentration, delivery formats, anthocyanin content disclosure, health claims, serving sizes and pricing patterns. Among the 121 products analysed, bilberry, elderberry, and tart cherry were the most commonly used anthocyanin sources, collectively representing 47% of the market. Capsules were the dominant delivery format (86%), and reported extract concentrations varied widely, with lower ratios (1–10:1) being most prevalent. Only 18% of products disclosed anthocyanin content (0.1–36%), with bilberry supplements accounting for the majority of reported values. Health claims were present on 69% of products and varied by source, with bilberry products most frequently promoting vision health, elderberry emphasising immune support, tart cherry targeting joint and exercise recovery, and cranberry focusing on urinary tract health. Declared extract (mg per serving) ranged from 10 mg to >1500 mg. Pricing varied substantially across products (AUD 0.02–7.40 per gram; mean AUD 0.78/g), with bilberry supplements consistently among the most expensive. Overall, these findings highlight considerable variability in formulation, disclosure, and health claim practices, underscoring the need for improved transparency and evidence-aligned representation of anthocyanins as bioactive pigments in the Australian nutraceutical market.