June 24, 1992

Oat Products and Lipid LoweringA Meta-analysis

Author Affiliations

From the Department of Family Practice and Community Health (Ms Ripsin and Dr Keenan) and the Division of Epidemiology (Drs Jacobs and Elmer), University of Minnesota, Minneapolis; the Department of Biological and Biomedical Sciences, University of Ulster at Jordanstown, Northern Ireland (Dr Welch); the Department of Community Health and Preventive Medicine, Northwestern University Medical School, Chicago, Ill (Drs Van Horn and Liu); the Department of Nutrition and Dietetics, King's College, London, England (Dr Turnbull); the Department of Human Nutrition and Foods, Virginia Polytechnic Institute, Blacksburg (Dr Thye); the Cancer Prevention Research Program, Fred Hutchinson Cancer Research Center, Seattle, Wash (Dr Kestin); the School of Human Ecology, Louisiana State University Agricultural Center, Baton Rouge (Dr Hegsted); the Preventive Cardiology Program, Department of Medicine, University of California, Irvine (Dr D. M. Davidson); Chicago (Ill) Center for Clinical Research, Rush-Presbyterian-St Luke's Medical Center (Dr M. H. Davidson and Ms Dugan); the Cancer Control Research Program, Duke Comprehensive Cancer Center, Duke University, Durham, NC (Dr Demark-Wahnefried); and Canyon Ranch Health Center, Lenox, Mass (Dr Beling).

JAMA. 1992;267(24):3317-3325. doi:10.1001/jama.1992.03480240079039

Objectives.  —To test the a priori hypothesis that consumption of oats will lower the blood total cholesterol level and to assess modifiers and confounders of this association.

Data Sources.  —A computerized literature (MEDLINE) search and the Quaker Oats Co identified published and unpublished trials as of March 1991. Raw data were requested for all trials.

Study Selection.  —Trials were included in summary effect size estimates if they were randomized and controlled, if a formal assessment of diet and body weight changes occurred, and, if raw data were not received, if there was enough information in the published report to perform calculations.

Data Synthesis.  —Twenty trials were identified. Using the methods of DerSimonian and Laird, a summary effect size for change in blood total cholesterol level of -0.13 mmol/L (-5.9 mg/dL) (95% confidence interval [Cl], -0.19 to -0.017 mmol/L [-8.4 to -3.3 mg/dL]) was calculated for the 10 trials meeting the inclusion criteria. The summary effect size for trials using wheat control groups was -0.11 mmol/L (-4.4 mg/dL) (95% Cl, -0.21 to -0.01 mmol/L [-8.3 to -0.38 mg/dL]). Calculation of Keys scores demonstrated that substituting carbohydrates for dietary fats and cholesterol did not account for the majority of blood cholesterol reduction. Larger reductions were seen in trials in which subjects had initially higher blood cholesterol levels (≥5.9 mmol/L [≥229 mg/dL]), particularly when a dose of 3 g or more of soluble fiber was employed.

Conclusion.  —This analysis supports the hypothesis that incorporating oat products into the diet causes a modest reduction in blood cholesterol level.(JAMA. 1992;267:3317-3325)