The Addition of Whole Grains to the Diets of Adults: A Study of Digestive Health and Natural Defenses

NCT01902394 | Completed

• 1 other identifier: 2720
• Study Type: interventional
• Target: 108
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to determine if substituting whole grains for refined grains in the diets of healthy adults over a period of 6 weeks alters the composition of the bacteria in the gut, and has beneficial effects on immune function, digestive health, cardiovascular health, regulation of body weight and composition, and vitamin K status. The investigators hypothesize that whole grain consumption over a period of 6 weeks will alter the gut microflora toward a more beneficial bacterial profile, improve the immune response while reducing oxidative stress and inflammatory markers, have favorable effects on factors influencing the regulation of body weight and composition,increase bacterial vitamin K synthesis, and beneficially effect surrogate markers of cholesterol synthesis/absorption, vitamin D concentrations, and whole genome DNA methylation patterns. In statin users it is hypothesized that, consumption of whole grains will alter statin pharmacokinetics by decreasing rate of statin absorption, resulting in more sustained plasma concentrations.

Conditions

Digestive Health and Immune Function

Keywords

digestive health and natural defenses

Outcome Measures

Primary Outcomes (5)

• change in T Cell-mediated immunity

  Delayed-type hypersensitivity (DTH) and lymphocyte proliferation will be measured at baseline (week 2 of washout period) and at week-6 of the diet intervention to assess adaptive immune function, specifically T cell-mediated immunity.

  week 2 of washout diet and week 6 of diet intervention

• change in Lymphocyte proliferation

  Whole blood collected at baseline (week 2 of washout period) and at week-6 of the diet intervention will be investigated for the ability of lymphocytes to proliferate by quantifying the incorporation of tritium following mitogen stimulation.

  week 2 of washout diet and week 6 of diet intervention

• change in Natural Killer Function

  The ability of peripheral blood mononuclear cells to bind and kill leukemia cells will be measured at baseline (week 2 of washout period) and at week-6 of the diet intervention

  week 2 of washout diet and week 6 of diet intervention

• change in Cytokines

  Peripheral blood and stool samples will be analyzed at baseline (week 2 of washout diet) and week-6 of diet intervention for cytokines.

  week 2 of washout diet and week 6 of diet intervention

• change in Salivary immunoglobulin A (IgA)

  Salivary IgA will be analyzed at baseline (week 2 of washout period) and at week-6 of the diet intervention.

  week 2 of washout diet and week 6 of intervention diet

Secondary Outcomes (20)

• change in gut microbiota composition

  week 2 of washout diet and week 6 of intervention diet

• change in cardiovascular health risk factors

  week 2 of washout diet and week 6 of intervention diet

• change in vitamin K status

  week 2 of washout diet and week 6 of intervention diet

• change in body composition

  week 2 of washout diet and week 6 of intervention diet

• change in appetite

  Weekly for 8 weeks

Study Arms (3)

Whole grain rich diet

EXPERIMENTAL

Participants in the whole grain (WG) group will receive a diet providing 100% of energy requirements in a diet rich in whole grains.

Other: Whole grains

Refined grain rich diet

PLACEBO COMPARATOR

Participants in the refined grain (RG) group will receive a diet providing 100% of energy requirements in a diet rich in refined grains.

Other: Refined grains

Negative control

NO INTERVENTION

Subjects randomized to the negative control group will consume their own usual diet (i.e. not receive foods and beverages from the study).

Interventions

Whole grains OTHER

Following completion of the baseline period (a 2-week run-in phase), participants in the WG group will receive a diet providing 100% of energy requirements in a diet rich in whole grains and the RG group will be provided with 100% of energy requirements in a diet rich in refined grains but otherwise similar to the WG diet for 6 weeks.

Whole grain rich diet

Refined grains OTHER

Following completion of the baseline period (a 2-week run-in phase), participants in the WG group will receive a diet providing 100% of energy requirements in a diet rich in whole grains and the RG group will be provided with 100% of energy requirements in a diet rich in refined grains but otherwise similar to the WG diet for 6 weeks.

Refined grain rich diet

Eligibility Criteria

• Age: 40 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy male and female subjects aged 40-65 y (women must be \> 1 year postmenopausal or had both ovaries removed, if premenopausal).
• Body mass index (BMI) 20-35 kg/m.2
• Pass screening blood and urine tests
• Creatinine ≤ 1.5 mg/dL
• glutamic oxaloacetic transaminase/serum glutamate pyruvate transaminase/total bilirubin ≤ twice the upper limit of normal range
• Fasting glucose \<125 mg/dL
• hematocrit ≥ 32%
• white blood cell count ≥ 1.8 x 103/mm3 (M)
• PLT ≥ 100 x 103/mm3 (thou/µL)
• Must be willing to be randomized.
• Those randomized to either the WG or RG groups must be willing to consume only study foods and beverages provided.

You may not qualify if:

• Self reported weight change \>4kg within the past 3 months.
• Have participated in a weight loss program within the last 3-months; eligible if in weight reduction program to maintain body weight.
• Not willing to reduce habitual daily fiber intake (including prebiotics) within 2 wk prior to enrollment to \< \~7g/1000kcal/d for men, or \<\~8g/1000kcal/d for women if currently consuming greater amounts.
• Not willing to stop consumption of probiotic or prebiotic supplements within 2 weeks prior to start of study if currently taking these, as well as during study participation.
• Vegetarian diet.
• Not willing to stop taking multivitamins, and supplements (with the exception of vitamin D and calcium), including fish oil or n-3 fatty acids and herbal supplements, for 30 days prior to or during study participation, if currently taking these.
• Regular use of laxatives, stool softeners, or anti-diarrheal medications, and medications influencing food intake and/or appetite.
• Not willing to undergo a 3-month washout period after colonoscopy prior to enrollment, and not willing to defer colonoscopy until after study completion.
• Eating disorder within the past 10 years.
• Disinhibited eating behavior as indicated by a score above 12 on the Three Factor Eating Questionnaire.
• Food allergies or aversions or other issues with foods that would preclude use of study diets, including gluten, milk, nuts, or eggs.
• Individuals identified during screening as having barriers expected to deter compliance with dietary requirements (e.g., stated dislike of study foods, inadequate resources to store and reheat meals, inability to adhere to food pick-up schedule).
• Alcohol consumption \>2 drinks per day.
• Not willing to abstain from alcohol consumption during the study.
• Smoking or using nicotine containing products in the last 6 months.

Sponsors & Collaborators

• Tufts University: lead
• General Mills: collaborator
• Tufts Medical Center: collaborator

Study Sites (1)

HNCRA at Tufts University

Boston, Massachusetts, 02111, United States

Location

Related Publications (3)

• Karl JP, Meydani M, Barnett JB, Vanegas SM, Barger K, Fu X, Goldin B, Kane A, Rasmussen H, Vangay P, Knights D, Jonnalagadda SS, Saltzman E, Roberts SB, Meydani SN, Booth SL. Fecal concentrations of bacterially derived vitamin K forms are associated with gut microbiota composition but not plasma or fecal cytokine concentrations in healthy adults. Am J Clin Nutr. 2017 Oct;106(4):1052-1061. doi: 10.3945/ajcn.117.155424. Epub 2017 Aug 16.

  PMID: 28814395 DERIVED

• Vanegas SM, Meydani M, Barnett JB, Goldin B, Kane A, Rasmussen H, Brown C, Vangay P, Knights D, Jonnalagadda S, Koecher K, Karl JP, Thomas M, Dolnikowski G, Li L, Saltzman E, Wu D, Meydani SN. Substituting whole grains for refined grains in a 6-wk randomized trial has a modest effect on gut microbiota and immune and inflammatory markers of healthy adults. Am J Clin Nutr. 2017 Mar;105(3):635-650. doi: 10.3945/ajcn.116.146928. Epub 2017 Feb 8.

  PMID: 28179226 DERIVED

• Karl JP, Meydani M, Barnett JB, Vanegas SM, Goldin B, Kane A, Rasmussen H, Saltzman E, Vangay P, Knights D, Chen CO, Das SK, Jonnalagadda SS, Meydani SN, Roberts SB. Substituting whole grains for refined grains in a 6-wk randomized trial favorably affects energy-balance metrics in healthy men and postmenopausal women. Am J Clin Nutr. 2017 Mar;105(3):589-599. doi: 10.3945/ajcn.116.139683. Epub 2017 Feb 8.

  PMID: 28179223 DERIVED

MeSH Terms

Interventions

Whole Grains

Intervention Hierarchy (Ancestors)

Edible Grain; Crops, Agricultural; Food; Diet, Food, and Nutrition; Physiological Phenomena; Seeds; Food and Beverages

Study Officials

• Simin N Meydani, DVM, PhD

  Human Nutrition Research Center on Aging

  PRINCIPAL INVESTIGATOR

• Junaidah B Barnett, MCH(N), PhD

  Human Nutrition Research Center on Aging

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director of the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts

Study Record Dates

• First Submitted: June 4, 2012
• First Posted: July 18, 2013
• Study Start: June 1, 2012
• Primary Completion: September 1, 2014
• Study Completion: September 1, 2014
• Last Updated: May 21, 2015

Record last verified: 2015-05

Locations

US (1)