The Dose-Response Effects of Lean Beef in a Mediterranean-Style Dietary Pattern on Cardiovascular Disease Risk Factors

Study Overview
=================
Brief Summary
-----------------
The objective of this study is to evaluate the effects of different quantities of lean beef (0.5, 2.5, 5.5 oz/day) on lipids, lipoproteins, and vascular health endpoints in the context of a modified Mediterranean dietary pattern that is representative of foods typically consumed in the United States.

Detailed Description
-----------------
The DASH (Dietary Approaches to Stop Hypertension) dietary pattern, the USDA Food Pattern, and the American Heart Association (AHA) Diet are all recommended for the reduction of LDL-C and blood pressure, two major risk factors for cardiovascular disease (CVD). The recommended food-based dietary patterns emphasize consumption of vegetables, fruits and whole grains; include low-fat dairy products, poultry, fish, legumes, non-tropical vegetable oils and nuts; and limit intake of sweets, sugar-sweetened beverages and red meats. The Mediterranean dietary pattern has gained widespread popularity because of an impressive evidence base showing health benefits in the prevention of many chronic diseases including CVD. The Mediterranean Diet Pyramid recommends that red meat be consumed less than 2 servings per week, with an emphasis on lean cuts. However, as the BOLD (Beef in an Optimal Lean Diet) study has demonstrated, lean beef can be included in a heart healthy dietary pattern that achieves both low density lipoprotein and blood pressure-lowering effects. The BOLD study utilized beef consumption levels of 4 or 5.4 ounces of lean beef daily, which is significantly higher than the American average of app. 3 ounces per day. This study will evaluate three levels of beef in the context of a Mediterranean diet, compared to an Average American diet.

Conditions
-----------------
Healthy Volunteers

Intervention / Treatment
-----------------
* Other: MED 0.5
* Other: MED 2.5
* Other: MED 5.5
* Other: AAD 2.5


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Body Mass Index between 20 and 40 kg/m2 Non-smoker Fasting glucose ≤ 126 mg/dl Exclusion Criteria: Low HDL-C (<15th percentile of US population) Use of cholesterol lowering medications Elevated blood pressure (systolic blood pressure > 160 mm Hg and diastolic blood pressure > 100 mm Hg) or use of medication to treat hypertension for less than 6 months Elevated triglycerides ( > 350 mg/dL) Active cardiovascular disease (such as a heart attack or procedure within the past six months or participation in a cardiac rehabilitation program within the last six months, stroke, or history/treatment for transient ischemic attacks in the past six months, or documented history of pulmonary embolus in the past six months) Presence of kidney disease, liver disease, gout, untreated or unstable hyper- or hypothyroidism, certain cancers, gastrointestinal disease, pancreatic disease, other metabolic diseases, or malabsorption syndromes Women who have given birth during the previous 12 months Pregnant women or women who plan to become pregnant or become pregnant during the study Lactating women Weight loss of ≥ 10% of body weight within 6 months prior to enrolling in the study Smokers or use of any tobacco products in past 6 months Known (self-reported) allergy or adverse reaction to study foods History of eating disorders or other dietary patterns which are not consistent with the dietary intervention (e.g., vegetarians, very low fat diets, high protein diets) Unable or unwilling to give informed consent or communicate with study staff Self-report of alcohol or substance abuse within the past 12 months and/or current acute treatment or rehabilitation program for these problems (long-term participation in Alcoholics Anonymous is not an exclusion) Other medical, psychiatric, or behavioral factors that in the judgment of the Principal Investigator may interfere with study participation or the ability to follow the intervention protocol

Ages Eligible for Study
-----------------
Minimum Age: 30 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: MED 0.5<br> | Other: MED 0.5<br>* Participants will be fed a Mediterranean diet providing 0.5 oz. per day of lean beef.<br>|
| Other: MED 2.5<br> | Other: MED 2.5<br>* Participants will be fed a Mediterranean diet providing 2.5 oz. per day of lean beef.<br>|
| Other: MED 5.5<br> | Other: MED 5.5<br>* Participants will be fed a Mediterranean diet providing 5.5 oz. per day of lean beef.<br>|
| Other: AAD 2.5<br> | Other: AAD 2.5<br>* Participants will be fed an average American diet providing 2.5 oz. per day of lean beef.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lipid/lipoprotein profile will be measured in blood | The following will be measured in the blood on 2 consecutive days at baseline (start of trial) and the end of each 4-week diet period: lipids and lipoproteins, apolipoproteins, lipoprotein particle number/size, and proprotein convertase subtilisin/kexin type 9 (PCSK9). | Week 0, end of diet period 1 (week 4), end of diet period 2 (week 9), end of diet period 3 (week 15), end of diet period 4 (week 21) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pulse Wave will be measured using Sphygmocor EXCEL | Pulse wave analysis and pulse wave velocity will be conducted. | Week 0, end of diet period 1 (week 4), end of diet period 2 (week 9), end of diet period 3 (week 15), end of diet period 4 (week 21) | 
| Markers of vascular health will be measured in blood | Adhesion molecules and endothelin-1 will be measured in the blood. | Week 0, end of diet period 1 (week 4), end of diet period 2 (week 9), end of diet period 3 (week 15), end of diet period 4 (week 21) | 
| Systemic inflammation will be measured in blood | Markers of systemic inflammation will be measured, such as fibrinogen, IL-6, TNF-alpha, serum amyloid A, and CRP. | Week 0, end of diet period 1 (week 4), end of diet period 2 (week 9), end of diet period 3 (week 15), end of diet period 4 (week 21) | 
| Fecal microbiota will be analyzed | Feces will be analyzed for bacterial typing. | Week 0, end of diet period 1 (week 4), end of diet period 2 (week 9), end of diet period 3 (week 15), end of diet period 4 (week 21) | 
| Measures of oxidative stress will be measured in urine | Urinary 8-iso-PGF-2α and urinary 15-keto-dihydro- PGF-2α will be measured. | Week 0, end of diet period 1 (week 4), end of diet period 2 (week 9), end of diet period 3 (week 15), end of diet period 4 (week 21) | 
| Blood glucose, serum insulin, and insulin c-peptide will be measured. | Blood glucose and serum insulin and insulin c-peptide will be measured. | Week 0, end of diet period 1 (week 4), end of diet period 2 (week 9), end of diet period 3 (week 15), end of diet period 4 (week 21) |