Want to stay trim? It may be time for tea!
Aside from enjoying green tea for its gentle caffeinated lift and calming theanine, you may want to add it to your daily routine to help keep extra pounds at bay. While there has long been an association between brewed green tea consumption and healthy weight, research has examined the mechanics of this remarkable natural medicine.
Researchers find that a combination green tea catechins and caffeine (a cup of green tea can have around 30 mg of caffeine) oxidizes fat, preserves lean muscle mass, and keeps our metabolic energy levels humming along. Other work has found that while the primary catechin epigallocatechin-3-gallate (EGCG) is well known for preventing oxidative DNA damage and potentially stopping tumors, it also activates an enzymatic pathway in the body that suppresses the creation of fat cells, and stimulates enzymes that help break down fats.
Janssens PL, Hursel R, Westerterp-Plantenga MS. Nutraceuticals for body-weight management: The role of green tea catechins. Physiol Behav. 2016 Aug 1;162:83-7.
Green tea catechins mixed with caffeine have been proposed as adjuvants for maintaining or enhancing energy expenditure and for increasing fat oxidation, in the context of prevention and treatment of obesity. These catechins-caffeine mixtures seem to counteract the decrease in metabolic rate that occurs during weight loss. Their effects are of particular importance during weight maintenance after weight loss. Other metabolic targets may be fat absorption and the gut microbiota composition, but these effects still need further investigation in combination with weight loss. Limitations for the effects of green tea catechins are moderating factors such as genetic predisposition related to COMT-activity, habitual caffeine intake, and ingestion combined with dietary protein. In conclusion, a mixture of green tea catechins and caffeine has a beneficial effect on body-weight management, especially by sustained energy expenditure, fat oxidation, and preservation of fat free body-mass, after energy restriction induced body-weight loss, when taking the limitations into account.
Suzuki T, Pervin M, Goto S, Isemura M, Nakamura Y. Beneficial Effects of Tea and the Green Tea Catechin Epigallocatechin-3-gallate on Obesity. Molecules. 2016 Sep 29;21(10).
Green tea has been shown to have beneficial effects against cancer, obesity, atherosclerosis, diabetes, bacterial and viral infections, and dental caries. The catechin (-)-epigallocatechin-3-gallate (EGCG) has shown the highest biological activity among green tea catechins (GTCs) in most of the studies. While several epidemiological studies have shown the beneficial effects of tea and GTCs on obesity, some studies have failed to do this. In addition, a large number of interventional clinical studies have shown these favorable effects, and cellular and animal experiments have supported those findings, and revealed the underlying anti-obesity mechanisms. One of the mechanisms is enhanced cellular production of reactive oxygen species, which is mediated through the pro-oxidant action of EGCG, leading to the activation of adenosine monophosphate-activated protein kinase, which suppresses gene and protein expression of enzymes and transcription factors involved in adipogenesis and lipogenesis, and stimulates those involved in lipolysis. Recently, scientific evidence supporting the beneficial anti-obesity effects of green tea and GTCs has been increasing. However, future investigations are still required to clarify the reasons for the inconsistent results reported in the human studies; to achieve this, careful adjustment of confounding factors will be required.