Document Type: Review Article
Nutrition Research Center, School of Nutrition and Food Science, Shiraz University of Medical Sciences, Shiraz, Iran
Overweight and obesity is a public health problem worldwide. Green tea catechins are a group of plant flavonoids from flavanol subgroup. The beneficial effects of catechins on weight loss and prevention of obesity has been previously acknowledged. A great number of animal and human studies have investigated the possible mechanisms of catechins action in prevention of obesity, but this area of research is still under investigation. What has been known for now is that the mechanisms of anti-obesity effects of catechins are very diverse. These mechanisms include increased fat oxidation, stimulation of sympathetic nervous system activity, upregulation of mRNA level of fat Î²-oxidation genes, downregulating expression of enzymes involved in fat synthesis, and increased expression of adipose tissue uncoupling proteins. Many of these effects are exerted through induction of genes or inhibition of transcription factors. Catechins can also inhibit fat absorption through suppression of pancreatic lipase. By correction of colonic microbiota, catechins improve production of small absorbable metabolites in the colon, which can display anti-obesity effects after absorption.