by Dr. Amy Wiesner
Green tea is another big seller on the market today promoted for its effects on weight loss, cancer and the cardiovascular and nervous systems. It is also a delicious, healthy addition to the diet that was first recorded 4,000 years ago in China. The longer, healthier lives of Asian populations partially attests to their tea drinking habits. Let’s look at both the old claims and the new research promoting this ancient herb.
Green tea comes from the same leaf as black tea, Camellia sinensis. The leaf is just not left to oxidize as black tea leaves are which allows breakdown of the pigments in the leaves, among other components. One of the things that lack of oxidation does to the leaf is allow the polyphenols, or antioxidants, to remain unprocessed. Antioxidants squelch free radical damage that promotes aging and cancer. They also help the immune system to function better. In ancient China, green tea was thought to enhance beauty and longevity, which can be attributed to the polyphenols found therein.
The most potent antioxidant polyphenols found in green tea are epigallocatechin gallate (EGCG) and epigallocatechin (ECG). One study in China found that green tea coupled with high levels of catechins from green tea promoted weight loss. A study in Japan found the same results. In addition, the study in Japan found the participants had lower levels of LDL cholesterol, the “bad” cholesterol. In another study, LDL and total serum cholesterol was found to be reduced by ingesting green tea, but the “good” cholesterol or HDL wasn’t found to be affected.
The polyphenols in green tea have been found to be both chemopreventive and anticarcinogenic (i.e., they both prevent and counteract cancer). This is due to the antioxidant properties of the polyphenols. It is also true that green tea decreases inflammation which is unhealthy.
Another component of green tea that promotes wellness is amino acid called l-theanine. This rare amino acid gives Camellia sinensis its taste. l-Theanine is responsible for causing a relaxed feeling in the body by promoting alpha waves in the brain; it also works as a neurotransmitter by increasing levels of dopamine. It can decrease blood pressure as well.
To add to green tea’s many wonderful benefits, it has also been shown to decrease estrogen levels when ingested daily. This has profound implications for estrogen related problems--fibrocystic breast disease, uterine fibroids, estrogen-sensitive cancers and menstrual disorders.
Once again, the ancients got it right. Green tea is indeed an amazing addition to daily life no matter who you are. Just make sure to check for interactions if you are on prescribed medications.
Image courtesy of GreenTeaTruth.org