Effects of Various Higher Fat and Lower Fat Snacks on Cardiovascular Risk Factors in Men and Women.

Cardiovascular Health Effects of Isocaloric Substitution of Polyunsaturated Fat Rich Snacks for Saturated and Trans Fat or Refined Carbohydrate Snacks in Moderately Hypercholesterolemic Individuals.

The purpose of this study is to determine whether snacks differing in fat amount and type result in changes in cardiovascular disease risk factors in men and women who have mildly elevated cholesterol levels. Our hypothesis is that a diet containing snacks rich in polyunsaturated fats lead to a more favorable cardiovascular disease risk profile than a diet containing snacks rich in saturated and trans fats or one containing low-fat snacks.

Study Overview

• Status: Completed
• Conditions: Hypercholesterolemia
• Intervention / Treatment: Behavioral: higher fat, high polyunsaturated fat diet; Behavioral: higher fat, high saturated and trans fat diet; Behavioral: lower fat diet

Detailed Description

The overall goals of this study are to determine whether snack foods rich in polyunsaturated fats (PUFA) produce beneficial effects on cardiovascular disease risk compared to snacks rich in saturated fats (SFA) and trans fats and snacks rich in refined carbohydrates. The primary objective of this study is to determine the effects of substituting n-6 PUFA (linoleic acid) from snack chips for SFA/trans fat and refined carbohydrate on serum lipids -principally LDL-C - and lipoproteins in moderately hypercholesterolemic men and women. A secondary objective is to assess effects on lipoprotein subclass particle size, intramyocellular lipids, and C-reactive protein (CRP). Forty-two men and women will be recruited to participate in a randomized, crossover, controlled feeding experiment for 3 periods of 4 weeks each. Each feeding phase will be separated by an 8-week washout period. The control diet will be a National Cholesterol Education Program Step 1 diet consisting of approximately 30% energy from total fat, <10% energy from SFA, 5% energy from PUFA, 15% energy from monounsaturated fatty acids (MUFA), 1% energy from trans fat, 55% energy from carbohydrates, and 15% energy from protein. To achieve an isocaloric substitution with PUFA, 300 kcal coming from low-fat, high-carbohydrate snacks will be removed from the Step 1 diet (NCEP diet) and replaced with 300 kcal of PUFA-rich snacks (LO diet). Similarly, 300 kcal from snacks rich in SFA/trans fat will replace the same 300 kcal from the high-carbohydrate from the Step 1 diet for the high SFA diet (SF diet). Subjects will consumed all foods provided by the GCRC and nothing else during each feeding phase. Breakfast and lunch meals will be consumed at the GCRC on weekdays and breakfast on Saturdays. All other meals will be packed and consumed at home. The primary study variable will be serum/plasma LDL-cholesterol. Secondary variables will include lipids and lipoproteins including total cholesterol (TC), HDL-cholesterol, VLDL-cholesterol, and triglycerides, and intramyocellular lipids. Exploratory variables will include assessment of lipid subclass particle size and CRP, a marker of systemic inflammation. Supportive variables will include fasting blood glucose and insulin, percent body fat mass, blood pressure and demographic information. All variables will be measured at baseline and endpoint of each feeding phase.

• Study Type: Interventional
• Enrollment: 42
• Phase: Phase 2

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• age 19-65
• body mass index 20-35
• weight stable for at least 3 months
• low-density lipoprotein cholesterol 130-180 mg/dL
• triglycerides < 150 mg/dL
• glucose < 126 mg/dL

Exclusion Criteria:

• smokers
• type 1 diabetes
• type 2 diabetes
• use of lipid-lowering medications
• hypertension
• pregnancy
• lactation
• planning to become pregnant during the period of the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
total cholesterol
triglycerides
low-density lipoprotein cholesterol
high-density lipoprotein cholesterol

Secondary Outcome Measures

Outcome Measure
blood pressure
waist circumference
C-reactive protein
body fat
lipoprotein a
very low-density lipoprotein cholesterol
LDL pattern A or B
intramyocellular lipid

Collaborators and Investigators

• Sponsor: University of Alabama at Birmingham
• Collaborators: SmartFoods, Inc.
• Investigators: Principal Investigator: Marie-Pierre St-Onge, PhD, University of Alabama at Birmingham

Publications and helpful links

General Publications

• St-Onge MP, Aban I, Bosarge A, Gower B, Hecker KD, Allison DB. Snack chips fried in corn oil alleviate cardiovascular disease risk factors when substituted for low-fat or high-fat snacks. Am J Clin Nutr. 2007 Jun;85(6):1503-10. doi: 10.1093/ajcn/85.6.1503.

Study record dates

Study Major Dates

• Study Start: March 1, 2005
• Study Completion: February 1, 2006

Study Registration Dates

• First Submitted: June 30, 2006
• First Submitted That Met QC Criteria: July 6, 2006
• First Posted (Estimate): July 10, 2006

Study Record Updates

• Last Update Posted (Estimate): September 14, 2007
• Last Update Submitted That Met QC Criteria: September 12, 2007
• Last Verified: September 1, 2007

More Information

Terms related to this study

• Keywords: cardiovascular disease; saturated fat; diet; trans fat; polyunsaturated fat; intramyocellular lipid
• Additional Relevant MeSH Terms: Metabolic Diseases; Lipid Metabolism Disorders; Hyperlipidemias; Dyslipidemias; Hypercholesterolemia
• Other Study ID Numbers: X041217008