Cholesterol is mostly insoluble in water, meaning it doesn't readily dissolve. Cholesterol travels in the blood stream in the form of lipoproteins. In the liver, cholesterol is converted into low-density lipoprotein(LDL) and high density lipoprotein (HDL). The only difference between the two is in the carrier molecule, this difference is very important in maintaining a healthy lifestyle.
LDL cholesterol, often called "bad" cholesterol, passes through the liver and flows to other cells where deposits are left to form on artery walls. These deposits can lead to arteosclerosis and many other health complications such as hight blood pressure, heart disease, and stroke. HDL cholesterol is often referred to as the "good" cholesterol. HDL cholesterol prevents the excess fats from depositing in our arteries. Total cholesterol levels <200 mg/dL is desirable for maintaining a healthy heart and lowering the risk for heart disease. Total cholesterol levels between 200 -239 mg/dL are considered borderline high risk, while people whose cholesterol levels exceed 240 mg/dL are certainly at high risk for high blood pressure and heart disease. Cholesterol is an important component of the cell membranes. It is a major precursor in the production of vitamin D, and the production of the hormones progesterone, estrogen, and testosterone. Therefore it is important to maintain a 5:1 ratio of LDL (Bad) cholesterol to HDL (Good) cholesterol. Green tea's high concentration of strong antioxidants called catechins increase the liver's LDL receptors, In turn these receptors work to decrease LDL, the so-called "bad cholesterol" in the blood. The LDL receptor binds LDL and clears it from the bloodstream. Green tea catechins are a type of polyphenol, a class of antioxidant and the main constituent of green tea.