Green tea contains some special compounds known as polyphenols. Polyphenols are made up of phytochemicals and these phytochemicals have some definite health-boosting properties. Polyphenols are antibacterial and antiviral, as well as being strong antioxidants. One polyphenol in particular, epigallocatechin (or EGCG), has been shown in clinical trials to enter the cells and shield DNA from hydrogen peroxide (a potent free radical).
Green tea has also been shown to protect against cancer, lower cholesterol levels, and reduce clotting of the blood. Green tea has been implicated in regulating blood sugar and insulin levels, and is even thought to promote the burning of fat.
Now, a recent study has shown that green tea may help those suffering from sleep apnea. Sleep apnea is a common sleep-breathing disorder. The soft tissues of the throat temporarily collapse and block the airway during sleep. This can happen many times throughout the night and can cause sufferers to repeatedly stop breathing. As you can imagine, this makes for a disruptive night of sleep! Symptoms of sleep apnea include loud snoring and gasping, and daytime sleepiness. Eventually, sleep apnea can lead to other health problems such as high blood pressure, morning headaches, hypertension, and memory loss. Researchers believe it is the loss of oxygen that damages the brain. During a sleep apnea episode, the lack of oxygen to the brain causes free radicals to multiply, increasing their damaging ability.
A research team at the Louisville School of Medicine in Kentucky found that green tea compounds helped to protect the brains of rats from the damage caused by this type of oxygen deprivation. The compounds responsible for this protective effect were the catechin polyphenols of green tea. The researchers also noted that rats given drinking water with green tea added performed better during standard learning and memory tests.
A few tips for making a good cup of tea: steep for three minutes to release all the health-promoting compounds. And researchers say that tea packed in tea bags actually releases more polyphenols than loose leaves do. Apparently, the tea in tea bags tends to be broken down into smaller particles, which helps more polyphenols to be dissolved in the hot water.