Green tea has been popular in parts of Asia for hundreds of years, both as a drink, and as a traditional remedy. Over the past few decades, Western science has taken a strong interest in traditional medicine, and many of the ingredients used in folk medicine have been subject to rigorous scientific investigation.
Green tea has to be one of the most studied of these, and it would be surprising if a lot of further research was not inspired by the great discoveries that have been made about this humble beverage.
In the western world, Green tea is probably best known for its ability to promote weight loss. The main active ingredient in green tea, epigallocatechin gallate (EGCG), is commonly used as an ingredient in weight loss formulations.
Green Tea and Antioxidants
The catechins found in green tea and in green tea extracts are strong antioxidants, which means they have a host of benefits, including the mitigation of exercise induced tissue damage. Additionally, green tea has been shown to have a positive effect on cardiovascular health. (If you want more details, check out our main article on green tea).
Although this tea has been the subject of a lot of research, and studies have proven that it has the ability to improve health, some of the mechanisms by which it can do this have been a mystery to scientists. A group of researchers in Korea set out to change this.
The scientists used mice as a model to look at the way green tea changes the metabolism of fat. The mice in the experiment were divided into four groups – normal diet, high fat diet, high fat diet + green tea, and high fat diet + an extract of green tea catechins - the ingredients that scientists believe are responsible for the tea's beneficial effects.
The researchers looked at enzymes in the liver, and the way they digested fat. They discovered that mice on a high fat diet had abnormally functioning liver enzymes, which broke down fat in a way that precipitated the metabolic illnesses of obesity. The mice on the high fat diets showed high blood triglycerides, glucose, and insulin, and abnormal levels of a hormone called leptin, which regulates appetite.
Green Tea and Diet
Mice receiving the same high fat diet along with either green tea or green tea extract showed normal enzyme function, and blood tests revealed that these mice had levels of triglycerides, glucose, insulin and leptin that resembled those in mice eating the low fat diet, showing that green tea protected mice from the metabolic effects of eating a high fat diet.
Green Tea Health Benefits
While this study showed that green tea works by normalising the abnormal liver enzyme function that occurs when mice consume a high fat diet, scientists need to experiment further in humans to see whether green tea has the same effect. The good news is that we already know that green tea is great for us, and this is just another piece of the puzzle. In the mean time, we are free to enjoy the health benefits of a cuppa.
The other great thing about this study is that it compared the metabolic effects of green tea and of green tea extract, and found them identical. People who are serious about their weight loss or who want the benefits of green tea on the go should check out some of the new concentrated green tea extracts on the market, like Tribeca Health's Green Tea X50 and Bsc BodyScience TX100, and feel confident in a super potent product that packs all the punch of the real thing.
Lee LS, Choi JH, Sung MJ, Hur JY, Hur HJ, Park JD, Kim YC, Gu EJ, Min B, KimHJ. Green tea changes serum and liver metabolomic profiles in mice with high-fat diet-induced obesity. Mol Nutr Food Res. 2015 Jan 28.