Effects of rice bran oil on serum lipids and insulin resistance in type 2 diabetic patients

• Main Authors: Yi-Ting Chen, 陳譯庭
• Other Authors: 鄭心嫻
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/88564269876166008282

碩士 === 臺北醫學大學 === 保健營養學研究所 === 96 === Recent studies have shown that hyperlipidemic individuals who replace cooking oils with rice bran oil have significant decreases in plasma total cholesterol and triglyceride concentrations. In animal studies, diabetic rats fed a 15% rice bran oil diet had lower plasma triglyceride levels and lower insulin resistance, as well as greater fecal neutral sterol and bile acid excretion. In spite of such studies, the effects of rice bran oil on patients with type 2 diabetes mellitus are not yet fully understood. Therefore, the aim of this study was to investigate the effect of rice bran oil supplementation for 5 weeks on concentrations of plasma lipids and insulin resistance in individuals with type 2 diabetes mellitus. This was a randomized, single-blind, placebo-controlled trial. Thirty-five type 2 diabetic patients, 30 to 80 years of age, volunteered to participate in this study, which was conducted at Taipei Medical Hospital and Lo-Tung Pohai Hospital. The subjects were randomized into two groups: (1) a placebo group that consumed soybean oil and (2) a group that consumed rice bran oil (RBO group). The placebo group consumed soybean oil in imitation milk (a 250-mL/serving provided 18 g soybean oil in 1 serving/day), and the RBO group consumed rice bran oil in imitation milk (a 250-mL/serving provided 18 g rice bran oil in 1serving/day) for 5 weeks. During the intervention period, the subjects made no other changes in their usual diets, lifestyles, or medications. The only dietary change was the addition of soybean oil or rice bran oil in imitation milk at breakfast. Oral glucose tolerance tests were administered at the beginning and the fifth week of the study. After 5 weeks of rice bran oil consumption, subjects in the RBO group had significant decreases in serum total cholesterol concentration and plasma polyunsaturated fatty acids level, and tends to reduce low density lipoprotein cholesterol concentration, but no significant difference in insulin resistance indexes (HOMA-IR). After 5 weeks of soybean oil supplementation, subjects in the placebo group had significant increases in serum low-density lipoprotein cholesterol concentrations and in HOMA-IR indexes, but significant decreases in plasma monounsaturated fatty acid levels. In conclusion, ingestion of 18 g rice bran oil daily for 5 weeks in type 2 diabetic patients significantly decreases serum total cholesterol concentration, and tends to reduce low density lipoprotein cholesterol concentration, however, dose not affect insulin resistance.