Short-term, but not acute, intake of New Zealand blackcurrant extract improves insulin sensitivity and free-living postprandial glucose excursions in individuals with overweight or obesity

Abstract: Impaired postprandial glucose handling and low-grade systemic inflammation are risk factors for developing insulin resistance in individuals with overweight or obesity. Acute ingestion of anthocyanins improves postprandial glucose responses to a single carbohydrate-rich meal under strictly controlled conditions. Purpose: Examine whether acute and short-term supplementation with anthocyanin-rich New Zealand blackcurrant (NZBC) extract can improve postprandial glucose responses to mixed-macronutrient meals. Methods: Twenty-five overweight (BMI > 25 kg m2) sedentary individuals participated in one of the following double-blinded, randomised controlled trials: (1) ingestion of 600 mg NZBC extract or placebo prior to consumption of a high-carbohydrate, high-fat liquid meal (n = 12); (2) 8-days supplementation with NZBC extract (600 mg day−1) or placebo, with insulin sensitivity and markers of inflammation assessed on day-7, and free-living postprandial glucose (continuous glucose monitoring) assessed on day-8 (n = 13). Results: A single dose of NZBC extract had no effect on 3 h postprandial glucose, insulin or triglyceride responses. However, in response to short-term NZBC extract supplementation insulin sensitivity was improved (+ 22%; P = 0.011), circulating C-reactive protein concentrations decreased (P = 0.008), and free-living postprandial glucose responses to both breakfast and lunch meals were reduced (− 9% and − 8%, respectively; P < 0.05), compared to placebo. Conclusion: These novel results indicate that repeated intake, rather than a single dose of NZBC extract, is required to induce beneficial effects on insulin sensitivity and postprandial glucose handling in individuals with overweight or obesity. Continuous glucose monitoring enabled an effect of NZBC extract to be observed under free-living conditions and highlights the potential of anthocyanin-rich supplements as a viable strategy to reduce insulin resistance

Anti-inflammatory Components from Functional Foods for Obesity

Obesity, defined as excessive fat accumulation that may impair health, has been described throughout human history, but it has now reached epidemic proportions with the WHO estimating that 39% of the world’s adults over 18 years of age were overweight or obese in 2016. Obesity is a chronic low-grade inflammatory state leading to organ damage with an increased risk of common diseases including cardiovascular and metabolic disease, non-alcoholic fatty liver disease, osteo-arthritis and some cancers. This inflammatory state may be influenced by adipose tissue hypoxia and changes in the gut microbiota. There has been an increasing focus on functional foods and nutraceuticals as treatment options for obesity as drug treatments are limited in efficacy. This chapter summarises the importance of anthocyanin-containing fruits and vegetables, coffee and its components, tropical fruit and food waste as sources of phytochemicals for obesity treatment. We emphasise that preclinical studies can form the basis for clinical trials to determine the effectiveness of these treatments in humans