Antiobesity effects of green tea catechins: a mechanistic review.
Study Goal
The researchers aimed to review the evidence for mechanisms by which green tea catechins (GTC) may influence body weight and fat reduction in humans.
Results Summary
The study found that GTC consumption (270 mg to 1200 mg/day) may reduce body weight and fat, potentially through increased energy expenditure, fat oxidation, and other mechanisms like appetite modification and decreased nutrient absorption. Caffeine in green tea may act synergistically with GTC to enhance these effects.
Population
Humans (general, no specific subpopulation mentioned).
Effective Dosage
270 mg to 1200 mg/day.
Duration
Not specified.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
consumption of GTC (270 mg to 1200 mg/day) | decrease | body weight | - | - | may reduce | #1 |
consumption of GTC (270 mg to 1200 mg/day) | decrease | fat | - | - | may reduce | #2 |
GTC | increase | sympathetic nervous system (SNS) activity | - | - | influences | #3 |
GTC | increase | energy expenditure | - | - | increasing | #4 |
GTC | increase | oxidation of fat | - | - | promoting | #5 |
caffeine | increase | SNS activity | - | - | influences | #6 |
caffeine | increase | energy expenditure | - | - | may act synergistically with GTC to increase | #7 |
caffeine | increase | fat oxidation | - | - | may act synergistically with GTC to increase | #8 |
GTC | neutral | appetite | - | - | modifications in | #9 |
GTC | increase | enzymes involved in hepatic fat oxidation | - | - | up-regulation of | #10 |
GTC | decrease | nutrient absorption | - | - | decreased | #11 |
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.