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ARS Home » Pacific West Area » Davis, California » Western Human Nutrition Research Center » Obesity and Metabolism Research » Research » Publications at this Location » Publication #336999

Research Project: Improving Public Health by Understanding Diversity in Diet, Body, and Brain Interactions

Location: Obesity and Metabolism Research

Title: The effects of moderate whole grain consumption on fasting glucose and lipids, gastrointestinal symptoms, and microbiota

item COOPER, DANIELLE - University Of California
item Kable, Mary
item MARCO, MARIA - University Of California
item DE LEON, ANGELA - University Of California
item Rust, Bret
item BAKER, JULITA - University Of California
item Horn, William
item BURNETT, DUSTIN - University Of California
item Keim, Nancy

Submitted to: Nutrients
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2017
Publication Date: 2/21/2017
Citation: Cooper, D.N., Kable, M.E., Marco, M.L., De Leon, A., Rust, B.M., Baker, J.E., Horn, W.F., Burnett, D., Keim, N.L. 2017. The effects of moderate whole grain consumption on fasting glucose and lipids, gastrointestinal symptoms, and microbiota. Nutrients. 9(2):173. doi: 10.3390/nu9020173.

Interpretive Summary: For over a decade the Dietary Guidelines for Americans have recommended that consumers eat about half of their grain products as whole grains, however, consumption of whole grains consistently falls below this amount. This study was conducted to determine if consumption of whole grains at the recommended level or higher provided health benefits to healthy adults. After a six week period during which the research volunteers consumed either whole grains or refined grains, we found that the amount of whole grains consumed was related to improvements in blood glucose, total cholesterol and LDL cholesterol such that the more whole grains consumed, blood glucose, cholesterol, and LDL cholesterol decreased. Consuming more refined grains did not have this effect. These results indicate that consumption of whole grains can alter these markers of health, but in general, consumption needs to be greater than 50% of grain intake.

Technical Abstract: This study was designed to determine if providing wheat, corn, and rice as whole (WG) or refined grains (RG) under free-living conditions will change parameters of health over a six-week intervention in healthy, habitual non-WG consumers. Measurements of body composition, fecal microbiota, fasting blood glucose, total cholesterol, HDL, LDL, and triglycerides were made at baseline and post intervention. Subjects were given adequate servings of either WG or RG products based on their caloric need and asked to keep records of grain consumption, bowel movements, and GI symptoms weekly. After six weeks, subjects repeated baseline testing. No significant differences were seen between RG and WG treatments based solely on treatment group. When percent consumption of the provided grain products was included in the analysis fasting blood glucose, total cholesterol, and LDL significantly decreased with increased consumption of the WGs. During week six, bowel movement frequency increased with increased WG consumption. No significant differences in microbiota were seen between baseline and post intervention, although, abundance of order Erysipelotrichales increased in RG subjects who ate more than 50% of the RG market basket products. Consumption of WGs can alter parameters of health, but intake needs to be greater than current recommendations.