The effect of an extract of green and black tea on glucose control in adults with type 2 diabetes mellitus: double-blind randomized study.
Recent evidence suggests that tea from Camellia sinensis (eg, green, oolong, and black tea) may have a hypoglycemic effect. We evaluated the ability of an extract of green and black tea to improve glucose control over a 3-month period. A double-blind, placebo-controlled, randomized multiple-dose (0, 375, or 750 mg per day for 3 months) study in adults with type 2 diabetes mellitus not taking insulin was performed. The primary end point was change in glycosylated hemoglobin at 3 months. The 49 subjects who completed this study were predominantly white with an average age of 65 years and a median duration of diabetes of 6 years, and 80% of them reported using hypoglycemic medication. After 3 months, the mean changes in glycosylated hemoglobin were +0.4 (95% confidence interval, 0.2-0.6), +0.3 (0.1-0.5), and +0.5 (0.1-0.9) in the placebo, 375-mg, and 750-mg arms, respectively. The changes were not significantly different between study arms. We did not find a hypoglycemic effect of extract of green and black tea in adults with type 2 diabetes mellitus.
Mackenzie
Todd
T
Department of Community and Family Medicine, Dartmouth Medical School, Hanover, NH 03755, USA. todd.mackenzie@dartmouth.edu
Leary
Lisa
L
Brooks
W Blair
WB
D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000378:metabolism*; D028241:Camellia sinensis / Q000737:chemistry*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy*; D004311:Double-Blind Method; D023381:Endpoint Determination; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010936:Plant Extracts / Q000494:pharmacology
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D010936:Plant Extracts