Effects of High Fruit, Vegetable, and Dairy Intake on Plasma Lipids and Blood Pressure in Healthy Individuals

Effects of a Modified Lower Carbohydrate, Higher Fat DASH Diet Plan on Plasma Lipids, Lipoprotein Particle Size, and Blood Pressure in Healthy Adults

The Dietary Approaches to Stop Hypertension (DASH) trial has been shown to reduce blood pressure and plasma total and LDL-cholesterol (C) compared to a Western diet, but shows no benefit on other blood lipid variables associated with cardiovascular disease (CVD) risk, namely HDL-cholesterol and triglycerides. The overall objective of this study is to determine whether modification of the DASH diet by substituting carbohydrate with fat will result in improvements in multiple biomarkers of CVD risk. Specifically, the investigators will test the hypotheses that modification of the DASH diet by reducing carbohydrate, primarily in the form of simple sugars and glycemic starches, and allowing for a more liberal intake of total and saturated fat, primarily from dairy foods, will: (1) improve lipoprotein markers of CVD risk (reduced total/HDL-C ratio, apolipoprotein B, small LDL particles, and increased HDL-C, apoAI, and large HDL particles); and (2) result in comparable reductions of systolic and diastolic blood pressure to those achieved with the standard DASH diet. The investigators will also assess the effects of the modified DASH diet on markers of insulin resistance and inflammation. Our main hypotheses will be tested by a controlled dietary intervention conducted in 40 healthy men and women who will be randomly allocated to consume, for 3 weeks each, a control Western diet, a standard DASH diet, and a modified low-carbohydrate DASH diet, separated by 2-week washout periods.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Disease; Dyslipidemia; Blood Pressure
• Intervention / Treatment: Other: Dietary Intervention; Other: Dietary Intervention; Other: Dietary Intervention

• Study Type: Interventional
• Enrollment (Actual): 36
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Berkeley, California, United States, 94705
      • Cholesterol Research Center, Children's Hospital Oakland Research Institute

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 22 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age 22 years and older
• Average systolic blood pressure <160 mm Hg and diastolic blood pressure 80 - 95 mm Hg measured on 2 separate days
• Non-smoking
• Agrees to abstain from alcohol and dietary supplements during the study
• Willing to consume all study foods as instructed

Exclusion Criteria:

• History of coronary heart disease, cerebrovascular disease, peripheral vascular disease, bleeding disorder, liver or renal disease, diabetes, lung disease, HIV, or cancer (other than skin cancer) in the last 5 years.
• Taking hormones or drugs known to affect lipid metabolism or blood pressure.
• Body Mass Index (BMI) > 35
• Total- and LDL-cholesterol > 95th percentile for sex and age.
• Fasting triglycerides > 500 mg/dl.
• Fasting blood sugar (FBS) > 126 mg/dl.
• Abnormal thyroid stimulating hormone
• Not weight stable
• Pregnant or breast-feeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: CROSSOVER
• Masking: DOUBLE

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dietary Intervention: Control Diet	Other: Dietary Intervention; 3 weeks of a typical Western diet pattern. 48% carbohydrate, 15% protein, 37% fat.; Other: Dietary Intervention; 3 weeks of a diet based on the Dietary Approaches to Stop Hypertension (DASH) diet plan. 57% carbohydrate, 18% protein, 25% fat.; Other: Dietary Intervention; 3 weeks of a reduced carbohydrate, higher fat modification of the DASH diet plan. 42% carbohydrate, 18% protein, 40% fat.
Experimental: Dietary Intervention: DASH-based diet	Other: Dietary Intervention; 3 weeks of a typical Western diet pattern. 48% carbohydrate, 15% protein, 37% fat.; Other: Dietary Intervention; 3 weeks of a diet based on the Dietary Approaches to Stop Hypertension (DASH) diet plan. 57% carbohydrate, 18% protein, 25% fat.; Other: Dietary Intervention; 3 weeks of a reduced carbohydrate, higher fat modification of the DASH diet plan. 42% carbohydrate, 18% protein, 40% fat.
Experimental: Dietary Intervention: Modified DASH diet	Other: Dietary Intervention; 3 weeks of a typical Western diet pattern. 48% carbohydrate, 15% protein, 37% fat.; Other: Dietary Intervention; 3 weeks of a diet based on the Dietary Approaches to Stop Hypertension (DASH) diet plan. 57% carbohydrate, 18% protein, 25% fat.; Other: Dietary Intervention; 3 weeks of a reduced carbohydrate, higher fat modification of the DASH diet plan. 42% carbohydrate, 18% protein, 40% fat.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Total:HDL-cholesterol ratio	4 weeks
HDL-cholesterol	4 weeks
Apolipoprotein B	4 weeks
Apolipoprotein AI	4 weeks
Small LDL particles	4 weeks
Large HDL particles	4 weeks
Total:HDL-cholesterol ratio	9 weeks
Total:HDL-cholesterol ratio	14 weeks
HDL-cholesterol	9 weeks
HDL-cholesterol	14 weeks
Apolipoprotein B	9 weeks
Apolipoprotein B	14 weeks
Apolipoprotein AI	9 weeks
Apolipoprotein AI	14 weeks
Small LDL particles	9 weeks
Small LDL particles	14 weeks
Large HDL particles	9 weeks
Large HDL particles	14 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Blood Pressure	End of each experimental diet (4 wks, 9 wks, and 14 wks)
Triglycerides	End of each experimental diet (4 wks, 9 wks, and 14 wks)
Total Cholesterol	End of each experimental diet (4 wks, 9 wks, and 14 wks)
LDL-Cholesterol	End of each experimental diet (4 wks, 9 wks, and 14 wks)
Lipoprotein Subclasses (HDL, LDL, IDL, VLDL)	End of each experimental diet (4 wks, 9 wks, and 14 wks)
HOMA-IR	End of each experimental diet (4 wks, 9 wks, and 14 wks)

Collaborators and Investigators

• Sponsor: UCSF Benioff Children's Hospital Oakland
• Collaborators: Dairy Management Inc.

Publications and helpful links

General Publications

• Chiu S, Bergeron N, Williams PT, Bray GA, Sutherland B, Krauss RM. Comparison of the DASH (Dietary Approaches to Stop Hypertension) diet and a higher-fat DASH diet on blood pressure and lipids and lipoproteins: a randomized controlled trial. Am J Clin Nutr. 2016 Feb;103(2):341-7. doi: 10.3945/ajcn.115.123281. Epub 2015 Dec 30.

Study record dates

Study Major Dates

• Study Start: July 1, 2011
• Primary Completion (Actual): December 1, 2013
• Study Completion (Actual): December 1, 2013

Study Registration Dates

• First Submitted: July 22, 2011
• First Submitted That Met QC Criteria: July 27, 2011
• First Posted (Estimate): July 28, 2011

Study Record Updates

• Last Update Posted (Estimate): March 26, 2015
• Last Update Submitted That Met QC Criteria: March 25, 2015
• Last Verified: March 1, 2015

More Information

Terms related to this study

• Keywords: blood pressure; cholesterol; carbohydrate; DASH diet
• Additional Relevant MeSH Terms: Metabolic Diseases; Lipid Metabolism Disorders; Cardiovascular Diseases; Dyslipidemias
• Other Study ID Numbers: MM3274