Postprandial Glycemic and Lipidemic Effects of Anthocyanins in Food Matrices of Differing Macronutrient Compositions

Abstract

ObjectivesWhile a diet rich in anthocyanins is encouraged as a strategy against metabolic disorders, the postprandial benefits of anthocyanin in commonly consumed meals of varying macronutrient compositions and food matrices are unknown. Using a well-characterized source of anthocyanin from black rice, we investigate the postprandial effects of black rice anthocyanin extract (BRAE) enrichment on the glycemic and lipidemic responses to a high-carbohydrate (HC) food and a high-fat (HF) meal challenge. MethodsIn two separate human trials of 24 participants each, the postprandial glycemic and lipidemic responses to HC BRAE-enriched bun, or HF BRAE-enriched burger meal were assessed. Clinically relevant blood biochemical markers for glucose, insulin, and lipids were measured. In addition, we simulated in-vitro digestion models to understand the mechanistic effects of anthocyanins on starch digestibility and lipase activity in the food matrices. ResultsIn-vivo, BRAE enrichment presented a 27-point glycemic index reduction of the HC bun. Significant improvements in postprandial HDL cholesterol and lipoproteins were observed in response to the HF BRAE-burger, while postprandial triglyceride levels did not differ. In-vitro, BRAE enrichment significantly reduced starch digestibility for the BRAE-bun, but not the burger. However, pancreatic lipase activity was greatly reduced in the burger with BRAE enrichment. Altogether, our work has demonstrated improvements in glycemic control with BRAE enrichment, via mechanisms inhibiting starch digestibility. BRAE enrichment also improved lipidemic control, in which our work suggests a modulatory effect of anthocyanins on lipoproteins in-vivo. ConclusionsFindings from this study suggest potential in using BRAE in food enrichment, for improved glycemic and lipidemic control via GI-lowering and lipoprotein modulatory effects. However, the benefits reaped from anthocyanin intake is food matrix-specific, and results should be adapted according to its food application. Funding SourcesThis research is supported by National University Health System and National University of Singapore under the Health Innovation Programme grants C-172–000-064–091 and N-172–000-120–001. Additional funding was provided by the Ministry of Education, via the Academic Research Fund Tier 1 grant R-143–000-A85-114.