A Plant-Based Meal Reduces Postprandial Oxidative and Dicarbonyl Stress in Men with Diabetes or Obesity more than an Energy- and Macronutrient-Matched Conventional Meal in a Randomized Crossover Study

Abstract Background: Increased oxidative/dicarbonyl stress and chronic inflammation are considered key pathological mediators in the progression of complications in type 2 diabetes (T2D) and obesity. Lifestyle and diet composition have a major impact. In this study, we tested the effects of a vegan (V) and a conventional meat containg (M) meal, matched for energy and macronutrients, on postprandial oxidative and dicarbonyl stress, inflammatory markers and appetite hormones. Methods: A randomised crossover design was used to evaluate T2D, obese and control participants (n=20 in each group), with serum concentrations of analytes determined at 0, 120 and 180 minutes. Repeated-measures ANOVA was used for statistical analysis.Results: Postprandial glucose, triglycerides and free fatty acid responses were similar after both meals. After the V-meal consumption, we observed decreased postprandial concentrations of oxidised glutathione (p˂0.001) and increased glutathione peroxidase activity (p=0.045) compared with the M-meal in T2D subjects. In obese participants, V-meal consumption increased postprandial concentrations of reduced glutathione (p=0.041) and decreased methylglyoxal concentrations (p=0.023). There were no differences in postprandial secretion of TNFa, MCP-1 or ghrelin, but we did observe higher postprandial secretion of leptin after the V-meal in T2D subjects (p=0.002) compared with the M-meal. Conclusions: The results show that a plant-based meal is efficient in ameliorating the postprandial oxidative and dicarbonyl stress compared to a conventional energy- and macronutrient-matched meal, indicating the therapeutic potential of plant-based nutrition in improving the progression of complications in T2D and obese patients.Registered under ClinicalTrials.gov Identifier No. NCT02474147.