Green tea shown to fight obesity
Pennsylvania State University researchers have discovered yet another impressive property of green tea - it can slow down weight gain and counter obesity. This recent study analyzed the health development of a test group of obese mice that were fed a high-fat diet mixed with green tea extracts, and compared it to that of a control group of obese mice that were fed the same diet, without the green tea compounds. The mice in the test group gained weight at a much slower rate than the mice in the control group, and they appeared to be in better health overall.
Assistant professor of food science in agricultural sciences, Joshua Lambert, who was part of this research, explained that "in this experiment, we see the rate of body weight gain slows down."
Green tea is believed to have originated in China, although many Asian cultures traditionally prepare and consume this type of tea. It is produced from the leaves of Camellia sinensis that have only undergone minimal oxidation during processing. Green tea has the highest content of antioxidants among commonly consumed foods and beverages, and that is why it has consistently attracted scientific attention over the last few decades.
Green tea can also provide the body with considerable amounts of carotenoids, vitamin C, and trace elements (including chromium, manganese, selenium and zinc). Both animal and human studies have revealed that green tea has the potential to reduce the risk of cardiovascular disease and to help with the prevention of tooth decay by improving bone quality and density, as well as to fight against different forms of cancer.
The study recently conducted at Penn State had the test mice on a high-fat diet enriched with Epigallocatechin-3-gallate (or EGCG), which is an important compound found in green tea that is associated with a reduced risk of cardiovascular disease. These mice gained weight at a 45% slower rate than the control group of mice, who were on the same high-fat diet.
The mechanism of action is believed to be linked to how the body absorbs fats. The analysis of fecal matter from the test mice revealed that they eliminated 30% more lipids than the mice in the control group, which implies that green tea may reduce lipid absorption.
Assistant professor Lambert explained: "[T]here seems to be two prongs to this. First, EGCG reduces the ability to absorb fat and, second, it enhances the ability to use fat." Moreover, green tea had no impact whatsoever on appetite, as both groups of mice consumed roughly equal amounts of food. To match the EGCG quantities used in the study, a normal person would have to drink around 10 cups of green tea per day; however, Lambert assures us that only a few cups per day may also help obese individuals control body weight.
He also added that although his study was conducted on mice, "human data, and there's not a lot at this point, shows that tea drinkers who only consume one or more cups a day will see effects on body weight compared to nonconsumers."
Assistant professor Lambert's team included Kimberly Grove and Sudathip Sae-tan, who are both graduate students in food science, as well Mary Kennett, professor of veterinary and biomedical sciences. The study was featured in the online version of the journal Obesity, and it is supported by the National Institute for Health.
The science team pointed out that although green tea interferes with lipid absorption in individuals of all body weights, its impact is more noticeable when used with overweight individuals who want to shake off extra pounds.