Effects of Egg Consumption and Choline Supplementation on Plasma Choline and Trimethylamine-N-Oxide in a Young Population

Background: Plasma trimethylamine-N-oxide (TMAO) concentrations have been associated with cardiovascular disease risk. Eggs are a rich source of choline, which is a precursor of TMAO. Objective: The effects of egg intake versus daily choline supplementation were evaluated on plasma choline and TMAO in a young, healthy population. Methods: Thirty participants (14 males, 16 females; 25.6 +/- 2.3 years; body mass index = 24.3 +/- 2.9 kg/m(2)) were enrolled in this 13-week crossover intervention. After a 2-week washout, participants were randomized to consume either 3 eggs/d or a choline bitartrate supplement (similar to 400 mg choline total in eggs or supplement) for 4 weeks. Following a 3-week washout, participants were switched to the alternate treatment. Dietary records were measured at the end of each period. Plasma TMAO and choline were measured at baseline and at the end of each dietary intervention. Gene expression of scavenger receptors associated with plasma TMAO were quantified at the end of each intervention. Results: Compared to the choline supplement, intake of total fat, cholesterol, selenium, and vitamin E were higher (p < 0.05), whereas carbohydrate intake was lower (p < 0.001) with consumption of 3 eggs/d. Fasting plasma choline increased 20% (p = 0.023) with egg intake, while no changes were observed with choline supplementation. Plasma TMAO levels were not different between dietary treatments or compared to baseline. Conclusions: Dietary choline appears to be more bioavailable via egg consumption when compared to a choline supplement. Plasma TMAO concentrations were not affected in healthy participants after 4 weeks of taking similar to 400 mg/d choline either via eggs or choline supplementation.