Antiobesity effects of green tea catechins: a mechanistic review.
Green tea catechins (GTC) are polyphenolic compounds present in the unfermented dried leaves of the plant, Camellia sinensis. Results from a number of randomized, controlled intervention trials have shown that consumption of GTC (270 mg to 1200 mg/day) may reduce body weight and fat. There are several proposed mechanisms whereby GTC may influence body weight and composition. The predominating hypothesis is that GTC influences sympathetic nervous system (SNS) activity, increasing energy expenditure and promoting the oxidation of fat. Caffeine, naturally present in green tea, also influences SNS activity, and may act synergistically with GTC to increase energy expenditure and fat oxidation. Other potential mechanisms include modifications in appetite, up-regulation of enzymes involved in hepatic fat oxidation, and decreased nutrient absorption. This article reviews the evidence for each of these purported mechanisms, with particular reference to studies in humans.
Provident Clinical Research, Glen Ellyn, IL 60137, USA.
Tia M
TM
Rains
Sanjiv
S
Agarwal
Kevin C
KC
Maki
D050154:Adiposity / Q000187:drug effects; D000818:Animals; D019440:Anti-Obesity Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D001067:Appetite Depressants / Q000494:pharmacology / Q000627:therapeutic use; D002110:Caffeine / Q000494:pharmacology / Q000627:therapeutic use; D002392:Catechin / Q000494:pharmacology* / Q000627:therapeutic use*; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D004734:Energy Metabolism / Q000187:drug effects; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects; D050356:Lipid Metabolism / Q000187:drug effects; D009765:Obesity / Q000188:drug therapy* / Q000378:metabolism*; D013662:Tea / Q000737:chemistry*; D015431:Weight Loss / Q000187:drug effects
D019440:Anti-Obesity Agents; D001067:Appetite Depressants; D013662:Tea; D002110:Caffeine; D002392:Catechin