Clinical trial NCT00438893: Effects of a Long Term Dietary Portfolio and of Sequential Removal of Food Components From the Diet
Official title: The Long-Term Effect of Viscous Fibers, Soy Protein, and Plant Sterol Foods in Combination on Serum Cholesterol and Other Risk Factors for Cardiovascular Disease
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hyperlipidemia
Cardiovascular Diseases
Hypercholesterolemia
Keywords: Viscous dietary fiber
Soy protein
Nuts
Plant sterols
Dietary Portfolio
Compliance
Blood lipids
Blood pressure
Lead sponsor: University of Toronto
Sponsor class: OTHER
Collaborators: name: Canada Research Chairs Endowment of the Federal Government of Canada
name: Natural Sciences and Engineering Research Council, Canada
name: Loblaw Companies Limited
name: Almond Board of California
name: Unilever R&D
First posted: 2007-02-22
Enrollment: 66
Sex: ALL
Minimum age (years): 21
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

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.

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.

Eligibility criteria: Inclusion Criteria:

* Healthy adult men and postmenopausal women currently enrolled in the long-term portfolio study
* Body mass index \<32 kg/m2
* Constant body weight over last 6 months preceding the onset of the study
* Fasting LDL-cholesterol concentration \>4.1 mmol/L at diagnosis

Exclusion Criteria:

* women of child-bearing potential
* major cardiovascular event (stroke or myocardial infarction)
* positive molecular diagnosis of familial hypercholesterolemia
* secondary causes of hypercholesterolemia (hypothyroidism, unless treated \& on a stable dose of L-thyroxine, renal or liver disease)
* use of cholesterol-lowering medications
* serum triglycerides \>4.5 mmol/L
* blood pressure \> 145/90 mmHg
* diabetes and/or major disorders such as liver disease, renal failure or cancer
* major surgery \<6 months prior to randomization
* alcohol consumption \>2 drinks per day

Primary outcomes:
measure: Total cholesterol
timeFrame: At weeks 0, 2,4, 8,12, 18, 24, 34, 44, 52; then every 2 months to a total of 5 years
measure: LDL cholesterol
timeFrame: At weeks 0, 2,4, 8,12, 18, 24, 34, 44, 52; then every 2 months to a total of 5 years
measure: C-reactive protein
timeFrame: At weeks 0, 12, 24, 34, 52; then every 6 months to a total of 5 years
measure: Blood pressure
timeFrame: At weeks 0, 2,4, 8,12, 18, 24, 34, 44, 52; then every 2 months to a total of 5 years
Secondary outcomes:
measure: Body Weight
timeFrame: At weeks 0, 2,4, 8,12, 18, 24, 34, 44, 52; then every 2 months to a total of 5 years
measure: Apolipoprotein A1 and B
timeFrame: At weeks 0, 2,4, 8,12, 18, 24, 34, 44, 52; then every 2 months to a total of 5 years
measure: Lp(a)
timeFrame: At weeks 0, 24, 52; then every 6 months to a total of 5 years
measure: Routine Biochemistry and hematology measurements
timeFrame: At week 0, 12, 24 and every 6 months to 5 years
measure: Compliance to dietary portfolio components
timeFrame: At years, 1, 2, 3, 4 and 5
measure: 24 hour urinary markers and electrolytes (optional)
timeFrame: At week 0 and end of years 1, 2, 3, 4 and 5
measure: Oxidative stress markers
timeFrame: week 0 and every 6 months to 5 years
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Clinical Nutrition & Risk Factor Modification Centre, St. Michael's Hospital Health Centre
state: Ontario
Study officials:
affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto
name: David JA Jenkins, MD, PhD, DSc
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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. doi: 10.1053/meta.2002.35578.
citation: 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. doi: 10.1001/jama.290.4.502.
citation: 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. doi: 10.1016/s0026-0495(03)00260-9.
citation: Jenkins DJ, Kendall CW, Faulkner DA, Nguyen T, Kemp T, Marchie A, Wong JM, de Souza R, Emam A, Vidgen E, Trautwein EA, Lapsley KG, Holmes C, Josse RG, Leiter LA, Connelly PW, Singer W. Assessment of the longer-term effects of a dietary portfolio of cholesterol-lowering foods in hypercholesterolemia. Am J Clin Nutr. 2006 Mar;83(3):582-91. doi: 10.1093/ajcn.83.3.582.
citation: Jenkins DJ, Kendall CW, Nguyen TH, Marchie A, Faulkner DA, Ireland C, Josse AR, Vidgen E, Trautwein EA, Lapsley KG, Holmes C, Josse RG, Leiter LA, Connelly PW, Singer W. Effect of plant sterols in combination with other cholesterol-lowering foods. Metabolism. 2008 Jan;57(1):130-9. doi: 10.1016/j.metabol.2007.08.016.