Effects of Consumption of Beef from Variably Fed Cattle on Anthropometric Measurements, Serum Parameters and Fatty Acid Composition in Healthy Men and Women

Abstract

Background: Despite the large body of convincing evidence and the leaner beef cuts now available, controversy over the relationship between red meat consumption and coronary heart disease risk factors continues. Several reports have shown that, as compared with grain-fed beef, pasture-fed beef contains increased concentrations of β-carotene and α- tocopherol, high levels of long chain n-3 PUFAs, a more desirable n-6/n-3 ratio and increased levels of CLA all substances reported to have favourable biological effects on human health. Objective: The objective of the present study was to investigate the effects of lean beef from three different cattle production systems, pasture-fed beef [P], pasture and grain supplemented-beef [M] and feedlot-beef [F] on anthropometric measurements, serum parameters and fatty acid composition in healthy men and women. Design: Forty-eight apparently healthy subjects [24 men and 24 women], were randomly assigned to consume a balanced diet [from a catering service] each of the three beef types for four weeks. Each participant consumed each diet with a period of wash up of 21 days between the different diets. Three groups of 16 subjects [8 men and 8 women] rotated through the three experimental periods. Results: In men systolic blood pressure was lower in P [109.8 vs 115.8 mmHg] than in F. The other anthropometric measurements were not affected by the beef type in either sex. However, the three diets caused significant changes from the baseline values of weight, systolic pressure, BMI and PM in both men and women. No significant differences were detected in the serum parameters and fatty acid proportion between the three diets. However, significant differences with the baseline values were found. Conclusions: No significant differences were found in the different variables studied between the three experimental diets. However, all the diets significantly affected the baseline values of the variables studied which followed a similar trend but with variable intensity according to the beef diet and sex.