Abstract
This feeding trial evaluated the impact of the Dietary Approaches to Stop Hypertension diet on changes in plasma choline, choline metabolites, and ceramides in obese older adults; 28 adults consumed 3oz (n = 15) or 6oz (n = 13) of beef within a standardized DASH diet for 12 weeks. Plasma choline, betaine, methionine, dimethylglycine (DMG), phosphatidylcholine (PC), lysophosphotidylcholine (LPC), sphingomyelin, trimethylamine-N-oxide (TMAO), L-carnitine, ceramide, and triglycerides were measured in fasted blood samples. Plasma LPC, sphingomyelin, and ceramide species were also quantified. In response to the study diet, with beef intake groups combined, plasma choline decreased by 9.6% (p = 0.012); DMG decreased by 10% (p = 0.042); PC decreased by 51% (p < 0.001); total LPC increased by 281% (p < 0.001); TMAO increased by 26.5% (p < 0.001); total ceramide decreased by 22.1% (p < 0.001); and triglycerides decreased by 18% (p = 0.021). All 20 LPC species measured increased (p < 0.01) with LPC 16:0 having the greatest response. Sphingomyelin 16:0, 18:0, and 18:1 increased (all p < 0.001) by 10.4%, 22.5%, and 24%, respectively. In contrast, we observed that sphingomyelin 24:0 significantly decreased by 10%. Ceramide 22:0 and 24:0 decreased by 27.6% and 10.9% (p < 0.001), respectively, and ceramide 24:1 increased by 36.8% (p = 0.013). Changes in choline and choline metabolites were in association with anthropometric and cardiometabolic outcomes. These findings show the impact of the DASH diet on choline metabolism in older adults and demonstrate the influence of diet to modify circulating LPC, sphingomyelin, and ceramide species.