The objectives of this study are the following: 1) to determine the acute effect of whole grain barley on risk factors of cardiovascular disease compared to a diet low in whole grain, and 2) to compare the effects of whole grain barley to those of whole grain oats to determine if the response to these two grains is similar.

Whole grains contain bioactive components that may contribute to reduced risk of cardiovascular disease, and there may be significant differences among whole grain sources with respect to ability to alter biomarkers of cardiovascular disease. This acute study is designed to determine if whole grain barley improves postprandial lipid metabolism and improves endothelial function. Further, we will determine if acute consumption of whole grain barley versus acute consumption of whole grain oats results in differential response with respect to biomarkers of cardiovascular disease risk.

Inclusion Criteria:

• Men and women between the ages of 25-70 years
• Body mass index (BMI) ≥ 19 and ≤ 38
• Willingness and ability to make scheduled appointments at clinical site as required by study protocol

Exclusion Criteria:

• Do not regularly consume breakfast or dislike cereal for breakfast
• Known (self-reported) allergy or adverse reaction to grains (e.g., wheat, gluten, barley)
• Presence of kidney disease, liver disease, gout, hyperthyroidism, untreated or unstable hypothyroidism, certain cancers, gastrointestinal disease, pancreatic disease, other metabolic diseases, or malabsorption syndromes
• Type 2 diabetes requiring the use of oral antidiabetic agents or insulin
• Fasting triglycerides > 300 mg/dL
• Fasting glucose > 126 mg/dL
• Use of cholesterol lowering medication
• Blood pressure > 180/100 or hypertension treated with calcium channel blockers, direct acting vasodilators, or beta blockers
• Fingernails longer than 0.25 inch beyond the finger tip, or unwillingness to cut fingernails to this length during endothelial function testing
• History of bariatric or certain other surgeries related to weight control
• History of major surgery within 3 months of enrollment
• Smokers or other tobacco users (during 6 months prior to the start of the study)
• Antibiotic use during the intervention or for 3 months prior to the intervention period
• History of eating disorders or other dietary patterns which are not consistent with the dietary intervention (e.g., vegetarians, very low fat diets, high protein diets)
• Volunteers who have lost 10% of body weight within the last 6 months
• Unable or unwilling to give informed consent or communicate with study staff
• Self-report of alcohol or substance abuse within the past 12 months and/or current acute treatment or rehabilitation program for these problems (long-term participation in Alcoholics Anonymous is not an exclusion)
• Other medical, psychiatric, or behavioral factors that in the judgment of the Principal Investigator may interfere with study participation or the ability to follow the intervention protocol