EAL

DLM: Fiber (2001)

Citation:

Van Horn L. Fiber, lipids, and coronary heart disease. Circulation. 1997;95:2701-2704.

Worksheet created prior to Spring 2004 using earlier ADA research analysis template.

Study Design:

Consensus statement

Class:

R - Click here for explanation of classification scheme.

Quality Rating:

NEUTRAL: See Quality Criteria Checklist below.

Research Purpose:

Inclusion Criteria:

Exclusion Criteria:

Description of Study Protocol:

Epidemiological Studies: 1. Zutphen Study 2. 20-yr cohort study of 1001 middle-aged men in Ireland & Boston. 3. 12-yr follow up study of 859 men and women 50-79 yrs old. 4. 850 men in Yi province of China Clinical/Metabolic Studies: 1. 30 clinical studies over the past decade evaluated the impact of oats and other fiber-rich foods as part of a Step I or similar fat-modified diet in outpatient, free-living and controlled settings.

Data Collection Summary:

Description of Actual Data Sample:

Summary of Results:

Men in the lowest quintile of dietary fiber intake exhibited a 4x rate of CHD mortality compared with men in the highest quintile, even though total calories were about the same. Significant inverse association between fiber intake and risk of CHD, but the association diminished when other risk factors were controlled. A 6-g increment in daily fiber intake was associated with 25% ¯ in ischemic heart disease mortality, independent of calories, fat, and other dietary variables. Lower serum cholesterol and blood pressure were associated with intakes of fiber from oats and buckwheat. Total fat and dietary cholesterol intakes were also significantly ¯ in those with the highest fiber intakes, but caloric intakes were similar across all fiber groups. The greatest lipid-lowering benefits occur among persons with baseline cholesterol levels. Fiber from 2 servings of oats enhanced cholesterol reduction an additional 2% to 3% beyond what was achieved by fat modification. Fiber supplements containing psyllium have reported greater reductions of 15% in LDL-Chol as part of the usual American diet and 9% as part of a Step I diet. Observational epidemiological evidence consistently demonstrates lower incidence of CHD and other long-term diseases among those with the highest intakes of fruits, vegetables, and grains. Such a dietary pattern appears to offer protective effects that transcend lipid lowering and overall is typically lower in total fat, saturated fat and cholesterol. The greatest impact in ¯ total and LDL-Chol is derived from ¯ intakes of saturated fat and cholesterol as well as weight reduction in obese persons. Diets high in complex carbohydrates and fiber are associated with reduced mortality rates from CHD and other chronic diseases. Fiber found in oats, barley and pectin-rich fruits and vegetables provides adjunctive lipid-lowering benefits beyond those achieved by reductions in total and saturated fat alone. The AHA recommends a total dietary fiber intake of 25 to 30 g/d from foods, not supplements, to ensure nutrient adequacy and maximize the cholesterol-lowering impact of a fat-modified diet. Current dietary fiber intakes among adults in the US average about 15 g or half the recommended amount

Author Conclusion:

Funding Source:

Not-for-profit

Foundation associated with industry:

Reviewer Comments:

Quality Criteria Checklist: Review Articles
Relevance Questions
	1.	Will the answer if true, have a direct bearing on the health of patients?	Yes
	2.	Is the outcome or topic something that patients/clients/population groups would care about?	Yes
	3.	Is the problem addressed in the review one that is relevant to dietetics practice?	Yes
	4.	Will the information, if true, require a change in practice?	Yes

Validity Questions
	1.	Was the question for the review clearly focused and appropriate?	No
	2.	Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described?	No
	3.	Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified andappropriate? Wereselectionmethods unbiased?	No
	4.	Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methodsspecified,appropriate, andreproducible?	No
	5.	Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined?	Yes
	6.	Was the outcome of interest clearly indicated? Were other potential harms and benefits considered?	Yes
	7.	Were processes for data abstraction, synthesis, and analysis described? Were they applied consistently acrossstudies and groups? Was thereappropriate use of qualitative and/or quantitative synthesis? Was variation in findings among studies analyzed? Were heterogeneity issued considered? If data from studies were aggregated for meta-analysis, was the procedure described?	No
	8.	Are the results clearly presented in narrative and/or quantitative terms? If summary statistics are used, are levels ofsignificance and/or confidence intervals included?	No
	9.	Are conclusions supported by results with biases and limitations taken into consideration? Are limitations ofthe review identified anddiscussed?	Yes
	10.	Was bias due to the review's funding or sponsorship unlikely?	No