Cholesterol comes in two forms, ‘good' or HDL-cholesterol and ‘bad' or LDL-cholesterol. Doctors are very concerned about the balance of these two types of cholesterol. Ideally, there should be more good cholesterol than bad. Also, there should only be very small amounts of the bad cholesterol in your blood.

Imbalances in your levels of cholesterol can lead to many diseases, one of which is atherosclerosis. Atherosclerosis is a hardening of the arteries caused by damage caused by high levels of bad cholesterol and other factors.

Studies revealed that green tea consumption in rats appears to lower their levels of bad cholesterol and even prevents them from getting high cholesterol when they are on high cholesterol diets.

This has significant implications for the use of green tea in humans to prevent high cholesterol and heart disease. There are still more studies and research to be done before researchers can confirm that green tea indeed has such benefits.

Researchers have also studied how green tea was able to protect rats on high cholesterol diets from getting bad cholesterol. In 2000, a study came out that shed some light on how green tea is able to keep LDL-cholesterol levels down in laboratory rats. Doctors Teddy T.C. Yang and Marcel W.L. Koo studied the effects of Lung Chen tea consumption on a group of laboratory rats with high cholesterol diets.

Lung Chen tea is also known as Long Jing tea. It is a green tea, meaning that the leaves are unoxidized. Whereas other green tea leaves are steamed, Lung Chen tea is pan fried to stop the oxidation process. This tea is usually found to contain the highest levels of antioxidants, called catechins, of all teas. It's typically very expensive and has a sweet flavor.

The doctors fed a group of male laboratory rats different diets according to their group status. The first group got a regular diet of Purina Rat chow and unlimited amounts of tap water. This was the control group. The other rat groups were given a 1% cholesterol diet with 0.5% cholic acid.

Those in the cholesterol group were divided further into groups receiving 1%, 2% and 4% solutions of Lung Chen Tea to drink. One group didn't receive any of the tea, but did receive the high cholesterol diet.

After eight weeks, the doctors collected two day's worth of fecal matter from each of the groups and examined the contents. After nine weeks, they collected blood samples and examined the rat's livers.

Immediately, they noticed that the rats in the high cholesterol group that didn't get any Lung Chen tea had gained the most weight, while the rats in the 2% and 4% Lung Chen tea groups had actually lost a small amount of weight compared to the control group which remained on the rat chow.

Also, the blood samples revealed that while all the rats on the high cholesterol diet had a higher cholesterol level than those in the control group, the rats that had received the 2% and 4% solutions of Lung Chen tea had the lowest cholesterol levels of those in the high cholesterol group. It appeared that the Lung Chen tea protected them, which is what other studies previously had shown.

When the doctors examined the fecal content of the rats, they found that the groups with the 2% and 4% solutions of Lung Chen tea had higher levels of lipid and cholesterol excretion than those in the high cholesterol diet without any tea.

This means that the Lung Chen tea is working to keep the cholesterol levels in the blood down by keeping it from being absorbed in the intestinal tract. Doctors theorize that this may be one of the mechanisms by which Lung Chen tea and possibly other green teas operate to help protect the body from high cholesterol diets.

Of course, this is only a study in rats and still needs to be examined in humans, but there is definite evidence that drinking green teas can help you maintain lower cholesterol levels.