(P10-34-26) Adding Processed or Unprocessed Lean Red Meat to a US-Style Healthy Vegetarian Dietary Pattern Influence Fasting Plasma Trimethylamine N-oxide (TMAO) in Young Healthy Adults

Objectives: Cardiometabolic diseases, including cardiovascular disease, chronic kidney disease, and diabetes, are leading causes of death in the United States. Observational studies have associated increased risk of these cardiometabolic diseases with red meat intake and elevated plasma Trimethylamine N-oxide (TMAO) concentrations. We assessed the effects of adding 3 ounces/d of cooked unprocessed or processed lean red meats (pork and beef, URM, PRM) to a Healthy U.S.-Style lacto-ovo vegetarian (LOV) dietary pattern on TMAO. We hypothesized that the LOV intervention would lower TMAO compared to baseline, while the URM and PRM intervention would attenuate the reduction in TMAO.

Methods: The results presented are from a secondary, retrospective objective of a crossover, randomized, controlled trial with 19 young, healthy participants (42% female; age 26 ± 4 y; BMI 23 ± 3 kg/m², mean ± SD) who self-reported to consume an omnivorous dietary pattern. The study included three 3-week dietary interventions with all food provided, each separated by a 5-week washout period, where self-chosen unrestricted diets resumed. Intervention effects were analyzed using mixed-effects models adjusting for age, sex, and BMI. Data were Box–Cox transformed (λ = -0.25) for analysis, and LS mean values are presented. During the interventions, participants consumed either the LOV (control, N=15), URM (N=15), or PRM (N=16) diet.

Results: Within intervention, LOV did not change TMAO (-0.19 ± 0.38 µmol/L, LS-mean ± SE, p = 0.62), while URM and PRM increased TMAO (0.75 ± 0.38, p = 0.046 and 0.73 ± 0.37, p=0.013, respectively; time x diet, p=0.066).

Conclusions: These findings suggest that changing a Healthy U.S.-Style vegetarian dietary pattern to a Healthy U.S.-Style omnivorous dietary pattern by adding lean unprocessed or processed red meats may increase TMAO.

Funding Sources: Pork Checkoff, Beef Checkoff, North Dakota Beef Commission, and Meat Foundation