THE EFFECTS OF A DIET RICH IN LEAN BEEF ON MULTIPLE RISK FACTORS FOR CARDIOVASCULAR DISEASE: THE BEEF IN AN OPTIMAL LEAN DIET (BOLD) STUDY

Open Access
- Author:
- Roussell, Michael A
- Graduate Program:
- Nutrition
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- September 22, 2010
- Committee Members:
- Penny Margaret Kris Etherton, Dissertation Advisor/Co-Advisor
Penny Margaret Kris Etherton, Committee Chair/Co-Chair
Trent Gaugler, Committee Member
Sheila Grace West, Committee Member
Peter Gillies, Committee Member
John Patrick Vanden Heuvel, Committee Member - Keywords:
- lean beef
saturated fat
cardiovascular disease
nutrition
red meat - Abstract:
- Background: Beef often is excluded in cholesterol-lowering diets as a means of controlling saturated fatty acids (SFA). However, the effects of a dietary pattern that meets dietary recommendations for SFA (<7% calories) and includes lean beef on cardiovascular disease (CVD) risk factors have not been evaluated. Objective: To examine the effects of a cholesterol-lowering diet containing lean beef (BOLD 4.0 oz/d; BOLD+ 5.4 oz/d) on low density lipoprotein cholesterol (LDL-C), and compare these effects to an Average American Diet (AAD). Design: Thirty six moderately hypercholesterolemic individuals (LDL-C >110 mg/dL) completed a randomized crossover controlled feeding study. Participants were fed 4 interventions diets; AAD [33% total fat, 12% SFA, 49% carbohydrate (CHO), 19% protein (PRO), 0.7 oz beef/d], DASH (27% total fat, 6% SFA, 50% CHO, 19% PRO, 1.0oz beef/d), BOLD (28% total fat, 6% SFA, 54% CHO, 19% PRO, 4.0 oz beef/d), and BOLD+ (28% total fat, 6% SFA, 46% CHO, 28% PRO, 5.4 oz beef/d) for five weeks with a 1 week washout between diets. Lipids, lipoproteins, apolipoproteins, blood pressure (BP), blood vessel function, C-Reactive Protein (CRP), Heme oxgense-1 (HO-1) were measured at the beginning of the intervention and at the end of each diet period. Equations were developed to predict TG and high density lipoprotein cholesterol (HDL-C) changes from AAD based on changes in food group intakes (recommended by MyPyramid.gov and the DASH diet) between DASH, BOLD, BOLD+ and AAD. Results: There were significant reductions (p<0.05) in total cholesterol (TC) and LDL-C in response to the DASH (-19.0 ±4.3 and -14.4 ±3.7 mg/dL), BOLD (-18.6 ±4.1 and -13.5 ±3.6 mg/dL), and BOLD+ (-19.6±4.1 and -13.5 ±3.8 mg/dL) diets versus the AAD (-8.5 ±4.1 and -5.5 ±3.9 mg/dL). Systolic BP (SBP) was only significantly reduced following the BOLD+ diet compared to AAD (-4.24 mm Hg). Significant reductions also were observed for Apo A1, Apo C-III, and Apo C-III bound to Apo A1 particles following the BOLD and BOLD+ (p<0.05) compared to AAD. Arterial stiffness was reduced following the BOLD (10.37 ± 3.0%) diet compared to AAD (14.47 ± 3.6%), with no other changes in vascular function. There were no significant differences between the HDL-C changes predicted using previously validated equations, and the MyPyramid.gov food group model or the DASH diet food group model. HO-1 levels remained unchanged throughout the intervention. No significant changes were observed in relative gene expression of HO-1, monocyte chemotactic protein-1, chemokine (C-C motif) receptor 2, gp91phox, or Biliverdin IXα reductase mRNA in response to the dietary treatments. Conclusions: In conclusion, lean beef can be included in a cholesterol-lowering diet that is controlled for SFA; this dietary pattern elicits reductions in TC and LDL-C that are equivalent to heart-healthy plant protein-rich diets, such as the DASH diet. In addition, increasing total dietary protein by including lean beef and other animal proteins also is an effective strategy for reducing BP.