Cholesterol Good and Bad

First lets understand that our body does need cholesterol to make bile salts, hormones and vitamin D.
It is mainly produced by our liver. If the level of cholesterol in the blood is too high it will build up on the artery walls.

There are 2 main types of blood cholesterol: LDL considered as "Bad" cholesterol and HDL considered as "Good" cholesterol.

High amounts of the bad LDL deposit cholesterol on the artery walls forming plaques. More and more plaques narrow the arteries
and may eventually block blood flow. Is is for this reason LDL is considered the "Bad" cholesterol.
Saturated fats and trans fatty acids are the most responsible factors that raise blood cholesterol.
Monounsaturated fats and polyunsaturated fats found in nuts and fish for instance, can lower the LDL level.
In addition, soluble fiber found in fruits, oats, barley and legumes can also lower LDL.

The good HDL, on the other hand, takes excess cholesterol away and carries it back to the liver to be excreted. It can also
remove some of the cholesterol already attached to the artery walls. Therefore HDL is considered the "Good" cholesterol as
high levels of HDL in the blood can decrease the risk of heart disease. Physical activity can also raise HDL

Desirable level of Cholesterol

Total Cholesterol< 200 mg/dL (5.2 mmol/L)
LDL Cholesterol < 100 mg/dL (2.6 mmol/L)
HDL Cholesterol > 40 mg/dL (1.0 mmol/L)