Title

Low-fat dietary pattern and risk of cardiovascular disease: the Women's Health Initiative Randomized Controlled Dietary Modification Trial

Authors

Barbara V. Howard, Medstar Research Institute
Linda Van Horn, Northwestern University
Judith Hsia, George Washington University
JoAnn E. Manson, Harvard Medical School
Marcia L. Stefanick, Stanford University
Sylvia Wassertheil-Smoller, Albert Einstein College of Medicine
Lewis H. Kuller, University of Pittsburgh
Andrea Z. LaCroix, University of Washington
Robert D. Langer, Geisinger Health System
Norman L. Lasser, University of California at San Diego
Cora E. Lewis, University of Alabama
Marian C. Limacher, University of Florida
Karen L. Margolis, HealthPartners Research Foundation
W. Jerry Mysiw, The Ohio State University
Judith K. Ockene, University of Massachusetts Medical SchoolFollow
Linda M. Parker, University of Miami
Michael G. Perri, University of Florida
Lawrence Phillips, Emory University
Ross L. Prentice, Fred Hutchinson Cancer Research Center
John Robbins, University of California at Davis School of Medicine
Jacques E. Rossouw, National Heart, Lung, and Blood Institute
Gloria E. Sarto, University of Wisconsin–Madison
Irwin J. Schatz, University of Hawaii - Honolulu
Linda G. Snetselaar, University of Iowa
Victor J. Stevens, Kaiser Permanente
Lesley F. Tinker, Fred Hutchinson Cancer Research Center
Maurizio Trevisan, University at Buffalo
Mara Z. Vitolins, Wake Forest University School of Medicine
Garnet L. Anderson, Fred Hutchinson Cancer Research Center
Annlouise R. Assaf, Brown University
Tamsen Bassford, University of Arizona
Shirley A. A. Beresford, University of Washington - Seattle Campus
Henry R. Black, Rush University Medical Center
Robert L. Brunner, University of Nevada School of Medicine
Robert G. Brzyski, University of Texas
Bette J. Caan, Kaiser Permanente
Rowan T. Chlebowski, University of California
Margery Gass, University of Cincinnati College of Medicine
Iris A. Granek, State University of New York at Stony Brook
Philip Greenland, Northwestern University
Jennifer Hays, Baylor Medical College
David Heber, University of California
Gerardo Heiss, University of North Carolina
Susan L. Hendrix, Wayne State University School of Medicine
F. Allan Hubbell, University of California, Irvine
Karen C. Johnson, University of Tennessee
Jane Morley Kotchen, Medical College of Wisconsin

UMMS Affiliation

Department of Medicine, Division of Preventive and Behavioral Medicine

Date

2-8-2006

Document Type

Article

Subjects

Aged; Cardiovascular Diseases; Coronary Disease; *Diet, Fat-Restricted; Energy Intake; Fatty Acids; Female; Follow-Up Studies; Humans; Incidence; Middle Aged; Outcome Assessment (Health Care); Postmenopause; Primary Prevention; Proportional Hazards Models; Risk; Risk Factors; Stroke

Disciplines

Life Sciences | Medicine and Health Sciences | Women's Studies

Abstract

CONTEXT: Multiple epidemiologic studies and some trials have linked diet with cardiovascular disease (CVD) prevention, but long-term intervention data are needed. OBJECTIVE: To test the hypothesis that a dietary intervention, intended to be low in fat and high in vegetables, fruits, and grains to reduce cancer, would reduce CVD risk.

DESIGN, SETTING, AND PARTICIPANTS: Randomized controlled trial of 48,835 postmenopausal women aged 50 to 79 years, of diverse backgrounds and ethnicities, who participated in the Women's Health Initiative Dietary Modification Trial. Women were randomly assigned to an intervention (19,541 [40%]) or comparison group (29,294 [60%]) in a free-living setting. Study enrollment occurred between 1993 and 1998 in 40 US clinical centers; mean follow-up in this analysis was 8.1 years.

INTERVENTION: Intensive behavior modification in group and individual sessions designed to reduce total fat intake to 20% of calories and increase intakes of vegetables/fruits to 5 servings/d and grains to at least 6 servings/d. The comparison group received diet-related education materials.

MAIN OUTCOME MEASURES: Fatal and nonfatal coronary heart disease (CHD), fatal and nonfatal stroke, and CVD (composite of CHD and stroke).

RESULTS: By year 6, mean fat intake decreased by 8.2% of energy intake in the intervention vs the comparison group, with small decreases in saturated (2.9%), monounsaturated (3.3%), and polyunsaturated (1.5%) fat; increases occurred in intakes of vegetables/fruits (1.1 servings/d) and grains (0.5 serving/d). Low-density lipoprotein cholesterol levels, diastolic blood pressure, and factor VIIc levels were significantly reduced by 3.55 mg/dL, 0.31 mm Hg, and 4.29%, respectively; levels of high-density lipoprotein cholesterol, triglycerides, glucose, and insulin did not significantly differ in the intervention vs comparison groups. The numbers who developed CHD, stroke, and CVD (annualized incidence rates) were 1000 (0.63%), 434 (0.28%), and 1357 (0.86%) in the intervention and 1549 (0.65%), 642 (0.27%), and 2088 (0.88%) in the comparison group. The diet had no significant effects on incidence of CHD (hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.90-1.06), stroke (HR, 1.02; 95% CI, 0.90-1.15), or CVD (HR, 0.98; 95% CI, 0.92-1.05). Excluding participants with baseline CVD (3.4%), the HRs (95% CIs) for CHD and stroke were 0.94 (0.86-1.02) and 1.02 (0.90-1.17), respectively. Trends toward greater reductions in CHD risk were observed in those with lower intakes of saturated fat or trans fat or higher intakes of vegetables/fruits.

CONCLUSIONS: Over a mean of 8.1 years, a dietary intervention that reduced total fat intake and increased intakes of vegetables, fruits, and grains did not significantly reduce the risk of CHD, stroke, or CVD in postmenopausal women and achieved only modest effects on CVD risk factors, suggesting that more focused diet and lifestyle interventions may be needed to improve risk factors and reduce CVD risk.

CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov Identifier: NCT00000611.

Rights and Permissions

Citation: JAMA. 2006 Feb 8;295(6):655-66. Link to article on publisher's site

Related Resources

Link to article in PubMed

PubMed ID

16467234