Scientific Abstract

Background

A Mediterranean-Style Eating Pattern (Med Pattern) is associated with decreased risk of chronic disease and improved quality of life. Among the Med Pattern guidelines, it is suggested to limit red meat consumption.

Objective

This study assessed the effects of including higher amounts of unprocessed lean red meat in a Med Pattern on cardiometabolic disease (CMD) risk factors and emotional well-being including perceived quality of life and indexes of sleep. Based on previous randomized controlled feeding studies using healthy eating patterns, we hypothesized that consuming higher amounts of red meat would not influence Med Pattern-induced improvements in CMD risk factors and emotional well-being.

Materials & Methods

In a randomized investigator-blinded crossover study, 41 participants (aged 46±2 y, BMI 30.5±0.6 kg/m2) who were not already following a healthy eating pattern consumed a weight-maintenance Med Pattern for two 5-wk periods separated by a 4-wk washout period. The Med Patterns were either rich or restricted in lean unprocessed red meat (6 or 18 oz of beef/pork per week, respectively). Both diets contained 20/40/40% of total energy from protein/carbohydrate/fat, respectively, with a fatty acid ratio of 22/11/7% of total energy from monounsaturated/polyunsaturated/saturated fats, respectively. At baseline and during the last week of each intervention fasting blood pressure (BP), blood lipids and lipoproteins, glucose, and insulin were measured. Additionally, subjects wore an ambulatory BP monitor for 24 hours, a wrist-worm actiwatch for 4 days, and completed subjective questionnaires about perceived quality of life (SF-36) and indexes of sleep (Pittsburgh Sleep Quality Index), and daily mood (Profile of Mood States; POMS). Data were analyzed by a doubly repeated measures ANOVA adjusted for age, body mass, and sex using Tukey-Kramer adjusted p values (p<0.05). Data are presented as LS means and SEM.

CMD risk factor results

Consumption of a Med Pattern decreased BP parameters over time, except during sleep, and inclusion of higher amounts of unprocessed lean red meat did not influence these improvements (~3-6 and ~3-5 mmHg reduction for systolic and diastolic BPs, respectively). Consumption of a Med Pattern decreased all lipoprotein concentrations over time but greater reductions in total cholesterol (TC), LDL, and ApoB occurred with consumption of the Med Pattern higher in red meat [TC: -17 ± 4 and -9 ± 4 (time*diet p=0.029), LDL: -11 ± 4 and -3 ± 3 (time*diet p=0.023), -0.1   ±  0.0 vs 0.0  ±  0.0 mg/dL (time*diet p=0.041) for Med Pattern rich and restricted in red meat, respectively]. Fasting glucose and insulin did not change throughout the study.

Emotional well-being results

Consumption of a Med Pattern improved physical role, vitality, and subjective sleep quality, regardless of the amount of red meat consumed. No changes in daily mood occurred throughout the study, as indicated the POMS scores. Conclusion: Consumption of a Mediterranean-style eating pattern positively influenced cardiometabolic disease risk factors and perceived quality of life and indexes of sleep which were not blunted by the inclusion of a daily serving of lean unprocessed red meat.

Publications

ScienceDirect: https://www.sciencedirect.com/science/article/pii/S0022316622109624?via%3Dihub