Comparing postprandial inflammatory responses to a plant-based meat alternative, grass-finished beef, and grain-finished beef in healthy middle-aged adults: a 3-group randomized crossover trial

BACKGROUND: Consumer interest in grass-finished meat and plant-based meat alternatives is growing because of concerns about health and environmental sustainability. Although these options differ in nutrient composition, their acute effects on postprandial inflammation remain unclear. OBJECTIVES: This study aimed to compare acute postprandial inflammatory responses after the consumption of grass-finished beef, a plant-based meat alternative, and grain-finished beef. Secondary outcomes included subjective measures of hunger, fullness, and thirst. METHODS: (mean ± SD: 29.6 ± 3) consumed 3 dietary interventions: ground grass-finished beef, plant-based meat alternative, and ground grain-finished beef. Blood was collected at baseline and multiple time points over 5 h after eating to measure C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Hunger, fullness, and thirst were assessed using visual analog scales. Data were analyzed using linear mixed models, adjusting for baseline inflammation. RESULTS: No significant differences in postprandial inflammatory markers were observed across interventions (P = 0.64). CRP increased slightly (+0.05 to +0.38 mg/L), TNF-α decreased moderately (-0.75 to -1.08 pg/mL), and IL-6 increased slightly (+1.29 to +1.92 pg/mL) across interventions (all P > 0.05). Exploratory analyses indicated a marginal association between age and inflammatory responses (P = 0.12), with no effects of BMI or sex (P = 0.60 and 0.56). Subjective ratings of hunger, fullness, and thirst did not differ between interventions. CONCLUSIONS: Despite differences in nutrient composition, acute consumption of grass-finished beef, a plant-based meat alternative, and grain-finished beef did not elicit significantly different postprandial inflammatory responses. These findings suggest that, in the short term, the choice between these protein sources may not meaningfully impact inflammation. Further research is needed to explore potential long-term health implications. CLINICAL TRIAL REGISTRY: This was registered at https://clinicaltrials.gov/study/NCT05690061.