Corn and Heart Health Study (CHS)

Evaluating the Effects of Corn Flour Consumption on Cardio-metabolic Outcomes and the Gut Microbiome in Adults With High Cholesterol

The purpose of this study is to investigate the effects of 3 different corn flours: (1) whole grain corn flour, (2) 50% refined corn flour + 50% corn bran derived from whole corn meal, and (3) refined corn flour, on cardio-metabolic outcomes and changes in the gut microbiome.

Study Overview

• Status: Completed
• Conditions: Gut Microbiome; Cholesterol, LDL; Cholesterol, HDL
• Intervention / Treatment: Other: Refined cornmeal flour; Other: 50/50 refined cornmeal-bran mix; Other: Whole grain cornmeal flour

Detailed Description

Dietary fibers are extremely complex and foster health in a variety of ways that are not fully understood. The Adequate Intake of fiber (14 g per 1000 kcal consumed) is based on data that strongly support a relationship with cardiovascular disease prevention (Slavin, 2013). While cereal fibers have been shown to be most effective at reducing cardiovascular disease risk (IOM, 2002), the components of dietary fiber (e.g. germ, bran) that exert this effect remain inadequately studied in cardiometabolic outcomes. Further, specific types of dietary fiber (natural and synthetic) have been shown to increase beneficial microbial species in the gastrointestinal tract, which are accompanied by improvements in inflammatory and metabolic disease markers. Very little is known about how isolated or intact fiber in whole grains solicit beneficial health effects via microbial mechanisms. Our goal is to study both changes in cardiometabolic outcomes and the gut microbiome after consuming different types of corn-based meals.

Aim 1: To evaluate cardio-metabolic outcomes (primary outcome: LDL cholesterol) after consuming 48 g/d of whole grain corn flour, 50% refined corn flour + 50% corn bran derived from whole corn meal, and refined corn flour for 4 weeks in adult males and females with elevated LDL cholesterol in a crossover design.

Aim 2: To evaluate changes in the gut microbiome after consuming 48 g/d of whole grain corn flour, 50% refined corn flour + 50% corn bran derived from whole corn meal, and refined corn flour for 4 weeks in adult males and females with elevated LDL cholesterol in a crossover design.

• Study Type: Interventional
• Enrollment (Actual): 58
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Corrie M Whisner, PhD; Phone Number: 602-496-3348; Email: cwhisner@asu.edu

Study Locations

• United States
  • Arizona
    • Phoenix, Arizona, United States, 85007
      • Arizona Biomedical Collaborative

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy English and Spanish speaking males and females with elevated circulating cholesterol levels (LDL-c ≥ 120 mg/dL).
• Individuals with LDL-c > 190 mg/dL will be permitted to participate but must provide a letter from their doctor stating that they are comfortable with their participation in the study.

Exclusion Criteria:

• recent weight fluctuations (> 5 lb in past 3 months), following specialized or restrictive diets (e.g. carbohydrate restriction, veganism)
• use of supplements (antioxidants, fiber, botanicals)
• allergies to dairy, egg, wheat, corn or gluten
• use of antibiotics in the past 2-3 months
• use of lipid lowering medications
• regular physical activity ≥ 30 min/d for ≥ 5 days/wk
• history of thyroid disorders, diabetes, heart disease, cancer, hepatitis, inflammatory conditions and/or gastrointestinal disorders which may impact gut function and metabolism
• anyone with a fear of needles or blood draws
• If female, women may not be pregnant or lactating during the study.
• Unwillingness to comply with study protocols will also result in exclusion from the study.
• Participants in this study will not be eligible if they are participating in other research studies at the same time.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: refined-50/50-whole; 48 g/d of corn flour was delivered to participants in two daily 24 g servings as pita breads and/or muffins via (1) refined cornmeal flour, followed by (2) 50/50 mix of refined cornmeal flour plus corn bran, followed by (3) whole grain cornmeal flour	Other: Refined cornmeal flour; 48 g/d of refined cornmeal flour served to participants as two daily 24 g servings via pita breads and/or muffins; Other: 50/50 refined cornmeal-bran mix; 48 g/d of a mix of 50% refined cornmeal flour and 50% corn bran flour served to participants as two daily 24 g servings via pita breads and/or muffins; Other: Whole grain cornmeal flour; 48 g/d of whole grain cornmeal flour served to participants as two daily 24 g servings via pita breads and/or muffins
Experimental: 50/50-whole-refined; 48 g/d of corn flour was delivered to participants in two daily 24 g servings as pita breads and/or muffins via (1) 50/50 mix of refined cornmeal flour plus corn bran, followed by (2) whole grain cornmeal flour, followed by (3) refined cornmeal flour	Other: Refined cornmeal flour; 48 g/d of refined cornmeal flour served to participants as two daily 24 g servings via pita breads and/or muffins; Other: 50/50 refined cornmeal-bran mix; 48 g/d of a mix of 50% refined cornmeal flour and 50% corn bran flour served to participants as two daily 24 g servings via pita breads and/or muffins; Other: Whole grain cornmeal flour; 48 g/d of whole grain cornmeal flour served to participants as two daily 24 g servings via pita breads and/or muffins
Experimental: whole-refined-50/50; 48 g/d of corn flour was delivered to participants in two daily 24 g servings as pita breads and/or muffins via (1) whole grain cornmeal flour, followed by (2) refined cornmeal flour, followed by (3) 50/50 mix of refined cornmeal flour plus corn bran	Other: Refined cornmeal flour; 48 g/d of refined cornmeal flour served to participants as two daily 24 g servings via pita breads and/or muffins; Other: 50/50 refined cornmeal-bran mix; 48 g/d of a mix of 50% refined cornmeal flour and 50% corn bran flour served to participants as two daily 24 g servings via pita breads and/or muffins; Other: Whole grain cornmeal flour; 48 g/d of whole grain cornmeal flour served to participants as two daily 24 g servings via pita breads and/or muffins
Experimental: refined-whole-50/50; 48 g/d of corn flour was delivered to participants in two daily 24 g servings as pita breads and/or muffins via (1) refined cornmeal flour, followed by (2) whole grain cornmeal flour, followed by (3) 50/50 mix of refined cornmeal flour plus corn bran	Other: Refined cornmeal flour; 48 g/d of refined cornmeal flour served to participants as two daily 24 g servings via pita breads and/or muffins; Other: 50/50 refined cornmeal-bran mix; 48 g/d of a mix of 50% refined cornmeal flour and 50% corn bran flour served to participants as two daily 24 g servings via pita breads and/or muffins; Other: Whole grain cornmeal flour; 48 g/d of whole grain cornmeal flour served to participants as two daily 24 g servings via pita breads and/or muffins
Experimental: 50/50-refined-whole; 48 g/d of corn flour was delivered to participants in two daily 24 g servings as pita breads and/or muffins via (1) 50/50 mix of refined cornmeal flour plus corn bran, followed by (2) refined cornmeal flour, followed by (3) whole grain cornmeal flour	Other: Refined cornmeal flour; 48 g/d of refined cornmeal flour served to participants as two daily 24 g servings via pita breads and/or muffins; Other: 50/50 refined cornmeal-bran mix; 48 g/d of a mix of 50% refined cornmeal flour and 50% corn bran flour served to participants as two daily 24 g servings via pita breads and/or muffins; Other: Whole grain cornmeal flour; 48 g/d of whole grain cornmeal flour served to participants as two daily 24 g servings via pita breads and/or muffins
Experimental: whole-50/50-refined; 48 g/d of corn flour was delivered to participants in two daily 24 g servings as pita breads and/or muffins via (1) whole grain cornmeal flour, followed by (2) 50/50 mix of refined cornmeal flour plus corn bran, followed by (3) refined cornmeal flour	Other: Refined cornmeal flour; 48 g/d of refined cornmeal flour served to participants as two daily 24 g servings via pita breads and/or muffins; Other: 50/50 refined cornmeal-bran mix; 48 g/d of a mix of 50% refined cornmeal flour and 50% corn bran flour served to participants as two daily 24 g servings via pita breads and/or muffins; Other: Whole grain cornmeal flour; 48 g/d of whole grain cornmeal flour served to participants as two daily 24 g servings via pita breads and/or muffins

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
LDL Cholesterol	Serum LDL cholesterol concentrations will be measured at the 0 and 4 weeks for each cornmeal intervention	0 weeks, 4 weeks
HDL Cholesterol	Serum HDL cholesterol concentrations will be measured at the 0 and 4 weeks for each cornmeal intervention	0 weeks, 4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gut Microbiome Diversity	Fecal gut microbiome communities will be sequenced using microbial DNA extracted from samples at 0 and 4 weeks for each cornmeal intervention. Amplified copies of the 16S rRNA gene will be evaluated for treatment differences in alpha (within-sample richness and evenness) and beta diversity (between-sample community structure). Relative and differential abundance of individual microbial taxa will also be measured.	0 weeks, 4 weeks

Collaborators and Investigators

• Sponsor: Arizona State University
• Collaborators: North American Millers Association - Corn Division
• Investigators: Principal Investigator: Corrie M Whisner, PhD, Arizona State University

Study record dates

Study Major Dates

• Study Start (Actual): March 20, 2018
• Primary Completion (Actual): August 30, 2023
• Study Completion (Actual): October 30, 2023

Study Registration Dates

• First Submitted: May 28, 2019
• First Submitted That Met QC Criteria: May 28, 2019
• First Posted (Actual): May 30, 2019

Study Record Updates

• Last Update Posted (Actual): February 5, 2024
• Last Update Submitted That Met QC Criteria: February 1, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Keywords: gut microbiome; gut microbiota; cholesterol; dietary fiber; whole grain
• Other Study ID Numbers: STUDY00007518

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No