Dietary protein and beef consumption predict for markers of muscle mass and nutrition status in older adults.

Objective: To determine the relationship of beef and protein intake to nutrition status, body composition, strength, and biochemical measures of vitamin and mineral status, inflammation and blood lipids in older adults.

Design: Cross-sectional observational study.

Setting: State of Ohio, U.S.A.

Participants: 142 adults ages 60-88.

Measurements: Subjects completed a Diet History Questionnaire, and questionnaires related to nutrition status and activity. Subjects also underwent measurements of body composition and strength, and a subset took part in a blood draw for biochemical measurements.

Results: Beef intake (g/d) was positively correlated to muscle mass measured by mid-arm muscle area (R=0.128, p=0.030). From multiple linear regression analysis, a 1oz/d (~28g/d) increase in beef consumption predicts for a 2.3cm(2) increase in mid-arm muscle area. Beef intake was negatively correlated to total (R=-0.179, p=0.035) and HDL (R=-0.247, p=0.004) cholesterol, and there was no association between beef and LDL-cholesterol, triglycerides, liver enzymes, or inflammatory markers. Protein intake (% of total energy) was positively correlated to nutrition status measured by the Mini Nutrition Assessment (R=0.196, p=0.020), and calf circumference (R=0.190, p=0.024), and these correlations remained when potential confounders were accounted for in multiple linear regression models. Protein intake was also positively correlated with BMI when analyzed with multiple linear regression.

Conclusions: Beef intake was positively associated with mid-arm muscle area, and protein intake was positively associated with nutrition status, calf circumference, and BMI in older adults. Consuming lean cuts of beef in moderation may be a healthy way in which older adults can increase protein intake, preserve muscle mass and improve nutrition status.