OmniHeart Trial: Macronutrients and Cardiovascular Risk

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00051350
Recruitment Status : Completed
First Posted : January 13, 2003
Last Update Posted : April 23, 2008
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)

Brief Summary:
To compare the effects on blood pressure and plasma lipids of three different diets--a carbohydrate-rich diet, a protein-rich diet, or a diet rich in unsaturated fat.

Condition or disease Intervention/treatment Phase
Cardiovascular Diseases Heart Diseases Atherosclerosis Hypertension Behavioral: Diet therapy Not Applicable

Detailed Description:


While there is widespread consensus that the optimal diet to reduce cardiovascular risk should be low in saturated fat, the type of macronutrient that should replace saturated fat (carbohydrate, protein or unsaturated fat) is a major, unresolved research question with substantial public health implications. The study will evaluate these three dietary approaches by studying their effects on established coronary risk factors and a selected group of emerging risk factors.


The study design was a randomized, three period cross-over feeding study that compared the effects on blood pressure and plasma lipids of a carbohydrate-rich diet patterned after the DASH diet (CARB) to two other diets, one rich in protein (PROTEIN) and another rich in unsaturated (UNSAT) fat, predominantly monounsaturated fat. The DASH diet has been shown to reduce blood pressure and LDL-cholesterol substantially, and is currently recommended by policy makers. During a one week run-in, all participants were fed samples of the three study diets (CARB, PROTEIN and UNSAT). Using a three period cross-over design, participants were then randomly assigned to the CARB, PROTEIN or UNSAT diet. Each feeding period lasted six weeks; a washout period of at least two weeks separated each feeding period. Throughout feeding (run-in and the three intervention periods), participants were fed sufficient calories to maintain their weight. Trial participants were 30 years of age or older, with systolic blood pressure of 120-159 mmHg or diastolic blood pressure of 90-99 mmHg. Primary outcomes variables were blood pressure and the established plasma lipid risk factors (LDL-C, HDL-C and triglycerides). Secondary outcomes include total cholesterol, apolipoproteins VLDL-apoB, VLDL-apoCIII, apolipoprotein B, non-HDL cholesterol, and lipoprotein(a).

Study Type : Interventional  (Clinical Trial)
Allocation: Randomized
Intervention Model: Crossover Assignment
Study Start Date : May 2002
Actual Primary Completion Date : March 2008
Actual Study Completion Date : March 2008

Information from the National Library of Medicine

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Ages Eligible for Study:   30 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Trial participants were generally healthy adults, aged 30 years and older, with a systolic blood pressure of 120 to 159 mm Hg or a diastolic blood pressure of 80 to 99 mm Hg. This range includes individuals with prehypertension (systolic, 120-139 mm Hg or diastolic, 80-89 mm Hg) and stage 1 hypertension (systolic, 140-159 mm Hg or diastolic, 90-99 mm Hg). Prehypertensive individuals are a group at high risk of developing hypertension and CVD, justifying special attempts to lower blood pressure.

Major exclusion criteria were diabetes, active or prior CVD, LDL cholesterol greater than 220 mg/dL (>5.70 mmol/L), fasting triglycerides greater than 750 mg/dL (>8.48 mmol/L), weight more than 350 lb (>159 kg), taking medications that affect blood pressure or blood lipid levels, unwillingness to stop taking vitamin and mineral supplements, and alcoholic beverage intake of more than 14 drinks per week.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00051350

Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
OverallOfficial: Lawrence Appel Johns Hopkins University

Publications automatically indexed to this study by Identifier (NCT Number): Identifier: NCT00051350     History of Changes
Other Study ID Numbers: 1192
First Posted: January 13, 2003    Key Record Dates
Last Update Posted: April 23, 2008
Last Verified: April 2008

Additional relevant MeSH terms:
Cardiovascular Diseases
Heart Diseases
Arterial Occlusive Diseases
Vascular Diseases