Effects of White Rice, Brown Rice, and Black Rice on Postprandial Glucose and Lipid Profiles in Healthy Korean Adults

A Randomized, Crossover Clinical Trial

This study was an open, 5-treatment, 5-sequence, 5-day cross-over randomized design clinical trial. The present study was carried out to compare the effects of white rice, brown rice, and black rice on postprandial glucose and lipid profiles in healthy human subjects, using a white bread as a positive control.

After a 12-hour fast, oral glucose and meal tolerance was measured with blood samples drawn at times 0, 15, 30, 45, 60, 90, 120, 150 and 180 minutes and TG was at time 0, 1, 2, 3, 4, 5 and 6 hours.

1. Serum levels of glucose, insulin, and TG were analyzed by biochemical autoanalyzer. The area under the curve (AUC) changes in blood glucose, TG were computed by the trapezoidal method.
2. Glycemic index(GI): the area under the glucose response curve after consumption of a test food divided by the area under the curve after consumption of a control food containing the same amount of carbohydrate and calculated using 50 g glucose as the reference.

Inclusion Criteria:

• Males, 19~60years old
• Bodyweight was more than 50 kg with ideal body weight within ±30%
• triglyceride (TG) levels less than 200 mg/dL
• Fasting blood glucose levels less than 100 mg/dL and an oral glucose tolerance test (OGTT) less than 140 mg/dL
• Able to give informed consent

Exclusion Criteria:

• Major medical illness such as cardiovascular, neurologic, psychiatric, renal, pulmonary and hepatic diseases
• History of disease that could interfere with the test products or impede their absorption such as gastrointestinal disease or gastrointestinal surgery
• Medical or psychological conditions deemed by the investigators to interfere with successful participation in the study
• Poor vital sign (systolic blood pressure: below 100 mmHg or above 150 mmHg, diastolic blood pressure: below 65 mmHg or above95 mmHg)
• Allergic or hypersensitive to any of the ingredients in the test products; treated with any drug within past 2 weeks
• Participation in any other clinical trials within past 2 months
• Alcohol consumption above 21 units per week or abnormal screening laboratory test
• Being judged by the responsible physician of the local study center as unfit to participate in the study