2009 年 44 巻 1 号 p. 52-56
Bay leaves (Laurus nobilis) have been shown to improve insulin function in vitro but the effects on people have not been determined. The objective of this study was to determine if bay leaves may be important in the prevention and/or alleviation of type 2 diabetes. Forty people with type 2 diabetes were divided into 4 groups and given capsules containing 1, 2 or 3 g of ground bay leaves per day for 30 days or a placebo followed by a 10 day washout period. All three levels of bay leaves reduced serum glucose with significant decreases ranging from 21 to 26% after 30 d. Total cholesterol decreased, 20 to 24%, after 30 days with larger decreases in low density lipoprotein (LDL) cholesterol of 32 to 40%. High density lipoprotein (HDL) cholesterol increased 29 and 20% in the groups receiving 1 and 2 g of bay leaves, respectively. Triglycerides also decreased 34 and 25% in groups consuming 1 and 2 g of bay leaves, respectively, after 30 d. There were no significant changes in the placebo group. In summary, this study demonstrates that consumption of bay leaves, 1 to 3 g/d for 30 days, decreases risk factors for diabetes and cardiovascular diseases and suggests that bay leaves may be beneficial for people with type 2 diabetes.