CHS: Corn and Heart Health Study
Study Details
Study Description
Brief Summary
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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
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 Design
Arms and Interventions
| 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
|
Outcome Measures
Primary Outcome Measures
- LDL Cholesterol [0 weeks, 4 weeks]
Serum LDL cholesterol concentrations will be measured at the 0 and 4 weeks for each cornmeal intervention
- HDL Cholesterol [0 weeks, 4 weeks]
Serum HDL cholesterol concentrations will be measured at the 0 and 4 weeks for each cornmeal intervention
Secondary Outcome Measures
- Gut Microbiome Diversity [0 weeks, 4 weeks]
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.
Eligibility Criteria
Criteria
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)
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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
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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.
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Arizona Biomedical Collaborative | Phoenix | Arizona | United States | 85007 |
Sponsors and Collaborators
- Arizona State University
- North American Millers Association - Corn Division
Investigators
- Principal Investigator: Corrie M Whisner, PhD, Arizona State University
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- STUDY00007518