Green tea is a brewed drink made from twigs, stems, leaves, and buds of Camellia sinensis. It is derived primarily through the oxidation of tea leaves that have undergone withering. The process is called fermentation” and yields a rich-green-colored liquid. The effect of oxidation is followed by a heating process, which is vital in controlling the bitterness and strength of the tea. The tea leaves are then dried to prevent further fermentation.
Green tea originated in China and has been used historically as a herbal medicine in China, Japan, and Korea. Many studies have also shown that green tea is a non-pharmacological way to help prevent or treat many diseases related to oxidative stress, such as cancer, cardiovascular disease, and neurodegenerative diseases.
It may improve brain function.
Green tea could improve cognition in elderly populations. In a study of older people with mild cognitive impairment, those who received green tea extract improved their understanding. However, the research was limited because no control group received green tea.
Antioxidants may lower the risk of some cancers.
Green tea is often promoted with a variety of health benefits. It has been said to help lower cholesterol, increase metabolism, and prevent cancer. However, these claims are not supported by any credible scientific evidence. Green tea has been found to contribute to weight gain and could be more harmful than beneficial. Caffeine intake is associated with an increased risk of heart disease.
Green tea contains caffeine, which increases blood pressure in high amounts and may contribute to cardiovascular diseases. A study of adults found that those who consumed green tea regularly had a higher risk of cardiovascular disease.
A review of epidemiological studies concluded that green tea and coffee could contribute to the development of coronary heart disease. Still, neither beverage was associated with a lower risk for coronary heart disease. People drinking more than six cups of coffee daily are at an increased risk.
It may help prevent cardiovascular disease.
Green tea contains flavonoids that have been found to reduce the risk of cardiovascular disease. Flavonoids are a class of polyphenols that help prevent LDL cholesterol oxidation, leading to plaque buildup in arteries. In addition, they are believed to lower cholesterol, increase the flexibility of blood vessels and decrease the risk of blood clots. However, the studies were limited because only the effect on blood pressure was examined.
The current evidence does not support using green tea for cardiovascular disease prevention or weight loss. Green tea may have accounted for some of the benefits observed in populations that regularly consume green tea. Still, no proof exists that this beverage is responsible for these benefits.
Weight loss potential
The antioxidant properties in green tea may have an impact on weight loss. In a study of overweight adults, those who took green tea extract lost more weight than those who took a placebo. However, it is essential to note that green tea did not appear to promote weight loss beyond its caffeine content.
May contribute to weight gain
There is a lack of evidence that green tea contributes to weight loss. In a study of Japanese adults, those who were supplemented with green tea had significantly more weight loss than those who did not increase with the supplement. However, they did not cause the same fat loss as candy or other non-caloric food items, suggesting that the effects were due to caffeine and other components in the beverage rather than green tea itself.
May increase caffeine consumption
Consumption of green tea and caffeine has been linked to an increased risk of cardiovascular disease. The caffeine in green tea may contribute to weight gain because it causes the body to release more insulin than it would if the beverage were not consumed. Over time, frequent caffeine consumption can lead to a chronically high level of insulin, which could contribute to weight gain.
It contains healthy bioactive compounds.
Green tea also contains catechins, bioactive compounds believed to have anti-cancer properties. In addition, green tea is often promoted as a natural source of antioxidants. There is not enough evidence to support using green tea as an antioxidant source in people with cancer.
Catechins may be helpful as a dietary supplement in people with cancer and in people who are undergoing chemotherapy. In addition, they may be used as an adjunct therapy to hormonal treatments such as tamoxifen. In animal studies, green tea and its compounds have been found to help prevent the development of breast cancer.
It might benefit liver function.
Flavonoids and other bioactive compounds in green tea have been shown to help improve liver function in adults with cirrhosis. Hepatic steatosis (fatty liver), a possible side effect of the treatment for advanced cancers, can be reversed with the dietary supplementation of catechins. However, scientific research on its impact on the liver is limited because it was only evaluated in people with cirrhosis.
The cost of HGH supplements in a study of people with a history of alcohol use, those who supplemented with green tea significantly decreased liver enzymes. However, it is uncertain whether catechins in green tea can be used as an adjunct treatment in people with hepatitis.
It may be good for the skin.
Green tea contains caffeine and has been found to reduce the appearance of wrinkles. Regular consumption of green tea may contribute to skin whitening and prevention of melanin formation. Green tea is also promoted as an effective treatment for psoriasis and eczema because of its high concentration of antioxidants and catechins, promoting healing.
Green tea can be helpful to people with cancer. It may protect the body from cancer-causing malignant cells, help treat or prevent cancer, and help some people cope with the side effects of the treatments they may be receiving. Green tea increases antioxidants in the blood, which are essential in preventing disease.