Evaluating Liking, Acceptability and Health Benefits of Grain Products (FL75)
The specific aims of the Grain Study are to determine if sensitivity to bitter taste affects the liking and acceptability of different grain products, to determine if exposure to different types of grain products, over a period of 6 weeks, changes liking and acceptability and to determine if the gut microbiota, bacterial fermentation products, or gastrointestinal function changes with consumption of whole grains or refined grains.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Prevention
|Official Title:||Evaluating Liking, Acceptability and Health Benefits of Grain Products|
- Change in the acceptability and liking of grain products [ Time Frame: 0, 6, 26, and 52 weeks ] [ Designated as safety issue: No ]Sensory evaluation of grain products
- Change in the gut microbiota and their fermentation products [ Time Frame: 0, 6, 26, and 52 weeks ] [ Designated as safety issue: No ]To determine if gut microbiota change over the intervention and if those changes persist over the long term.
- Change in gastrointestinal function [ Time Frame: 0, 6 weeks ] [ Designated as safety issue: No ]Does increased consumption of whole grain products improve gastrointestinal function?
|Study Start Date:||April 2010|
|Estimated Study Completion Date:||December 2013|
|Estimated Primary Completion Date:||December 2013 (Final data collection date for primary outcome measure)|
Experimental: Whole Grain
Whole grain products as defined by the American Association of Cereal Chemists (AACC) given in a market basket that contains eight commonly used grain products over six weeks.
Other: Whole grain foods
Eight commonly consumed whole grain products that meet the consumers Dietary Guidelines recommendations for a period of six weeks.
Placebo Comparator: Refined Grains
Time control compared to experimental intervention.
Other: Refined grains
Eight commonly consumed refined grain products given in amounts that fulfill the consumer's Dietary Guidelines for Americans recommendation over the course of six weeks.
Subjects will be recruited in accordance with inclusion and exclusion criteria listed below. During the screening process sensitivity to n-propyl-thiouracil (PROP) will be evaluated to classify subjects as "non-tasters", "tasters", and "supertasters".
Subjects within each PROP class will be assigned to one of two different grain product 'exposure' groups - Group 1 will receive predominantly Whole Grain (WG) products and Group 2 will receive predominantly Refined Grain (RG) products (ratio of WG to RG assignment will be 2:1). For a 6-week exposure period, subjects will receive weekly market baskets of grain products consisting of breakfast cereals, breads, snack items, and side dishes with the target of providing whole grains at a level of 50% of grain intake for the WG group (this is the current Dietary Guideline recommendation) and 15% for the RG group (this is the current estimated intake for U.S. adults). Before and after grain exposure, subjects will rate the acceptability and liking of numerous grain products. To accomplish this, subjects will participate in sensory evaluation tests using these products, and they will provide information using validated questionnaires and take implicit association tests. During the 6 week study period, subjects will record use of the market basket grain products, and provide subjective scores for taste, convenience, nutrition, and general liking. The quality of the total dietary intake will be assessed using unannounced 24-h recalls. Biological samples will also be collected from subjects. Blood and urine samples will be collected to evaluate risk factors of chronic disease, and biomarkers of whole grain intake, fruits and vegetables. Saliva and fecal samples will be collected to measure changes in gut microbiota and to measure metabolites of bacterial fermentation. Breath hydrogen tests will be conducted to measure bacterial fermentation. Two weeks after the end of the intervention period, subjects will participate in a nominal group session to identify significant barriers and facilitators to inclusion of grain products into their diets. Follow-up visits at 26 and 52 weeks, post-intervention, will be scheduled with all subjects to re-evaluate acceptability, liking, and other variables related to whole grain intake.
|United States, California|
|Western Human Nutrition Research Center|
|Davis, California, United States, 95616|
|Principal Investigator:||Nancy Keim, PhD||USDA, Western Human Nutrition Research Center|
|Study Director:||William Horn, MS||USDA, Western Human Nutrition Research Center|