Green tea has always been thought to be good for losing fat. Now we know why

Green tea has been known for centuries for its antioxidant properties and medicinal, and modern science has therefore wanted to investigate whether it really has clear effects on metabolic diseases important such as diabetes or obesity. Now, a new study published in Cell wanted to delve deeper into its mechanisms and reveals that green tea significantly improves glucose sensitivity in obese mice.

The diet. To reach these conclusions, the research team put mice on a high-fat diet for four weeks to induce obesity. After this time, they divided the animals: one group continued with the high-fat diet and received a standardized green tea extract (500 mg per kg of body weight), while another group received only water. A third control group consumed a normal diet for comparison.

The temperature. The key to the study, and what differentiates it from many others, was temperature control. Mice were maintained in a “thermoneutrality” environment at 28°C. This is crucial because the usual laboratory temperature (about 22 °C) means cold stress for the mice, which forces them to spend more energy to stay warm and therefore lose ‘artificial’ weight.

This extra energy expenditure can mask the true effects of the substance studied, such as green tea in this case. In this way, by eliminating this factor, scientists were able to “cleanly” observe the real impact of green tea.

The result. They confirmed the powerful effect of green tea on weight control and metabolic health. According to a previous study by the same group, obese mice treated with green tea reduced their body weight by up to 30%, a very significant result. In the current research, it was noted that the treatment “effectively prevented body weight gain.”

But in addition to the weight, which can be very good, the most interesting thing is undoubtedly the ability of green tea to make the body better manage blood sugar. Obese mice treated with the extract were seen to restore their glucose levels to levels similar to those of healthy mice, as demonstrated by glucose and insulin tolerance tests (GTT and ITT).

Although if you look at the fasting values ​​there are also important changes, since the treated mice had lower sugar values ​​than the obese mice that were not treated.

Protective effect. One of the most notable findings was the effect protector on muscle mass. Obesity usually causes a reduction in the diameter of muscle fibers (atrophy), but the study revealed that green tea not only prevented this deterioration, but caused a “significant increase in the cross-sectional area of ​​muscle fibers.” This suggests that green tea protects muscle from the harmful effects of obesity.

The mechanism. There are several systems to understand why these effects occur in the body:

• Fat metabolism: treatment increases the expression of key genes involved in lipid uptake in the muscles, and the creation of new mitochondria is also enhanced, which in the end are the ones that will use up the energy.
• Glucose uptake: sugar uptake was improved by improving the number of insulin receptors in cells as well as the famous transporter GLUT4 which allows the muscles to capture and use this sugar much better by removing it from the bloodstream.
• Energy production: increasing the enzyme LDH in the body it is related to an increase in energy metabolism that increased in treated mice.

It’s not a miracle. Although the results are promising, researcher Rosemari Otton warns that this is not a miracle solution. The dose used in mice would be equivalent to about three cups of green tea a day for a human, but quality is essential.

Otton recommends the use of standardized extracts, since the tea bags we have in the supermarket do not always guarantee the quantity or quality of the flavonoids, which in the end are the beneficial compounds.

Images | Towfiqu barbhuiya

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