Effects of a Long Term Dietary Portfolio and of Sequential Removal of Food Components From the Diet
Study Details
Study Description
Brief Summary
The purpose of this study is to evaluate the long term effectiveness of the dietary portfolio, consisting of viscous fibers, soy products, nuts and plant sterols, as well as the effects of removing single food components from the dietary portfolio on cholesterol reduction and other cardiovascular risk factors.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Detailed Description
We have shown in 1-month metabolic studies that a dietary portfolio, consisting of soy products, viscous fibers, almonds and plant sterols in the form of margarine, can lower cholesterol to the same extent as first generation statins (cholesterol-lowering drugs). However, the long-term effectiveness of the dietary portfolio is not known. Furthermore, it is not known to what extent each of the food components contribute to the cholesterol reductions observed. We wish to therefore evaluate the long term effects of the dietary portfolio as well as the effects of removing single food components from the dietary portfolio on cholesterol reduction and other cardiovascular risk factors. We believe the removal of single food components will result in a reduction of the cholesterol-lowering effect to a similar extent as predicted with the cholesterol reductions observed when the food component is consumed alone.
Method:
66 subjects will be recruited for a 6-month to 5 year long-term dietary portfolio study with the option for continuation (re-consenting) at the end of 6, 12 or 24 months. The active dietary components consist of viscous fibers (including oat bran), soy products (including soy milk), almonds and plant sterols (sterol-enriched margarine). Lipids, blood pressure, body weight, and routine biochemical and hematology analyses will be performed over the 5 year period, with lipids and blood pressure measured at 2 monthly intervals. 40-50 subjects on the long term dietary portfolio study, all of whom will have been on the diet for at least 1 year, will be asked to remove a specific food component from their regular dietary portfolio for a 10 week period. After the 10 week period, subjects will be asked return to the normal dietary portfolio with all food components consumed and continue on the long-term dietary portfolio.
Bloods will be taken at weeks 0, 6 and 10 of the food component removal period; and at 2-monthly intervals for 20 weeks prior to and after the 10 week period while on the long-term dietary portfolio with all food components.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Other: A portfolio of cholesterol-lowering foods Dietary advice to consume a dietary portfolio of cholesterol-lowering foods |
Dietary Supplement: Dietary portfolio of cholesterol-lowering foods
A plant based dietary portfolio providing plant sterols (1.0g/1000 kcal), soy protein (22.5g/1000 kcal, viscous fibers 10 g/1000 kcal and almonds 22.5g/1000 kcal)
|
Outcome Measures
Primary Outcome Measures
- Total cholesterol [At weeks 0, 2,4, 8,12, 18, 24, 34, 44, 52; then every 2 months to a total of 5 years]
- LDL cholesterol [At weeks 0, 2,4, 8,12, 18, 24, 34, 44, 52; then every 2 months to a total of 5 years]
- C-reactive protein [At weeks 0, 12, 24, 34, 52; then every 6 months to a total of 5 years]
- Blood pressure [At weeks 0, 2,4, 8,12, 18, 24, 34, 44, 52; then every 2 months to a total of 5 years]
Secondary Outcome Measures
- Body Weight [At weeks 0, 2,4, 8,12, 18, 24, 34, 44, 52; then every 2 months to a total of 5 years]
- Apolipoprotein A1 and B [At weeks 0, 2,4, 8,12, 18, 24, 34, 44, 52; then every 2 months to a total of 5 years]
- Lp(a) [At weeks 0, 24, 52; then every 6 months to a total of 5 years]
- Routine Biochemistry and hematology measurements [At week 0, 12, 24 and every 6 months to 5 years]
- Compliance to dietary portfolio components [At years, 1, 2, 3, 4 and 5]
- 24 hour urinary markers and electrolytes (optional) [At week 0 and end of years 1, 2, 3, 4 and 5]
- Oxidative stress markers [week 0 and every 6 months to 5 years]
Eligibility Criteria
Criteria
Inclusion Criteria:
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Healthy adult men and postmenopausal women currently enrolled in the long-term portfolio study
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Body mass index <32 kg/m2
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Constant body weight over last 6 months preceding the onset of the study
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Fasting LDL-cholesterol concentration >4.1 mmol/L at diagnosis
Exclusion Criteria:
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women of child-bearing potential
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major cardiovascular event (stroke or myocardial infarction)
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positive molecular diagnosis of familial hypercholesterolemia
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secondary causes of hypercholesterolemia (hypothyroidism, unless treated & on a stable dose of L-thyroxine, renal or liver disease)
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use of cholesterol-lowering medications
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serum triglycerides >4.5 mmol/L
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blood pressure > 145/90 mmHg
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diabetes and/or major disorders such as liver disease, renal failure or cancer
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major surgery <6 months prior to randomization
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alcohol consumption >2 drinks per day
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Clinical Nutrition & Risk Factor Modification Centre, St. Michael's Hospital Health Centre | Toronto | Ontario | Canada | M5C 2T2 |
Sponsors and Collaborators
- University of Toronto
- Canada Research Chairs Endowment of the Federal Government of Canada
- Natural Sciences and Engineering Research Council, Canada
- Loblaw Companies Limited
- Almond Board of California
- Unilever R&D
Investigators
- Principal Investigator: David JA Jenkins, MD, PhD, DSc, Department of Nutritional Sciences, Faculty of Medicine, University of Toronto
Study Documents (Full-Text)
None provided.More Information
Publications
- Jenkins DJ, Kendall CW, Faulkner D, Vidgen E, Trautwein EA, Parker TL, Marchie A, Koumbridis G, Lapsley KG, Josse RG, Leiter LA, Connelly PW. A dietary portfolio approach to cholesterol reduction: combined effects of plant sterols, vegetable proteins, and viscous fibers in hypercholesterolemia. Metabolism. 2002 Dec;51(12):1596-604.
- Jenkins DJ, Kendall CW, Marchie A, Faulkner D, Vidgen E, Lapsley KG, Trautwein EA, Parker TL, Josse RG, Leiter LA, Connelly PW. The effect of combining plant sterols, soy protein, viscous fibers, and almonds in treating hypercholesterolemia. Metabolism. 2003 Nov;52(11):1478-83.
- Jenkins DJ, Kendall CW, Marchie A, Faulkner DA, Wong JM, de Souza R, Emam A, Parker TL, Vidgen E, Lapsley KG, Trautwein EA, Josse RG, Leiter LA, Connelly PW. Effects of a dietary portfolio of cholesterol-lowering foods vs lovastatin on serum lipids and C-reactive protein. JAMA. 2003 Jul 23;290(4):502-10.
- REB 03-043
- HC-CT#100934