Observational Assessments of Chicken, Beef, and Seafood Proportions with a Mediterranean-Style Healthy Dietary Pattern and Cardiovascular Risk Factor Changes: Post Hoc Analysis of a Controlled Feeding Trial

Background: We previously reported that consuming a Mediterranean-style healthy dietary pattern (MED-HDP) with lower vs. higher glycemic index foods differentially changed indices of postprandial glucose control and daily glycemic variability but did not influence improvements in cardiovascular health indices. Methods: Fifty-two adults (31 females, 21 males; aged 49 ± 11 y, BMI 31 ± 3.1 kg/m2, mean ± SD) with two or more features of metabolic syndrome participated for 12 weeks in the randomized, controlled trial with all foods provided. At dinner only, participants could select from protocol-approved foods, including unprocessed chicken breast, unprocessed lean beef, and unprocessed salmon and shrimp (seafood). Objective: Herein, we retrospectively assessed whether the frequency of consuming different sources of meat (i.e., the exposures) was associated with MED-HDP-induced changes in cardiovascular health indices (i.e., the outcomes). Results: Among all participants, consuming the MED-HDP foods (88% adherence) reduced fasting systolic (SBP) and diastolic (DBP) blood pressures and serum total cholesterol (TC), triglycerides (TGs), and HDL. More frequent consumption of chicken at dinner, in place of beef and seafood, was associated with greater reductions in SBP (p = 0.034 and p = 0.047 for replacing beef and seafood, respectively) and DBP (p = 0.021 and p = 0.043, respectively). Frequency of chicken, beef, and seafood intakes at dinner did not associate with the reductions in serum TC, TG, HDL, or LDL. Conclusions: These results support that adoption of a MED-HDP improved multiple cardiovascular risk factors among middle-aged and older adults at elevated cardiovascular risk. The observed modest associations between more frequent consumption of unprocessed chicken at dinner and greater blood pressure reductions, which do not mean that eating more chicken at dinner causes lower blood pressure, warrant independent replication.