Effects of a Short‐Term Vegan Challenge in Older Adults on Metabolic and Inflammatory Parameters—A Randomized Controlled Crossover Study

Abstract

ScopeA long‐term vegan diet carries the risk of insufficient protein and micronutrient intake for older adults. However, even a short‐term (48 h) vegan diet exerts positive metabolic effects in younger adults. In this study, we investigate the feasibility and effects of a short‐term vegan challenge on metabolic and inflammatory markers in older adults.Method and resultsIn this randomized controlled crossover‐study, 30 healthy older adults (≥65 years) are assigned to either a 48 h ad libitum vegan or omnivorous diet. During the vegan diet, participants exhibit lower protein (p = 0.001) and fat intake as well as higher carbohydrate and dietary fiber intake, resulting in a lower caloric intake (all p < 0.001). Insulin concentrations (p = 0.042) and insulin resistance (p = 0.036) decline only after the vegan diet. The study observes reductions in serum glucose (p < 0.001), triglyceride (p = 0.005), and hsCRP (p = 0.044) concentrations and weight (p < 0.001), independent of the diet. Participants with low‐grade inflammation exhibit notable metabolic improvements after the vegan diet.ConclusionImprovements in insulin homeostasis are observed after the vegan diet, but meeting protein requirements are not feasible during the short‐term vegan challenge despite dietary counseling, which warrants concern.