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Saturated and unsaturated fats

Carbon can form four bonds with other atoms. Most carbons in a fatty acid chain are bonded to two adjacent carbons, and to two hydrogen atoms. When each carbon atom in a fatty acid chain forms four single bonds and has the maximum number of hydrogen atoms, the fatty acid chain is called saturated because it is “saturated” with hydrogen atoms. However, sometimes two adjacent carbons will from a double bond. In this case the carbons taking part in the double bond are each joined to only one hydrogen. Fatty acids that have carbon-carbon double bonds are known as unsaturated, because the double bond can be ‘broken’ and an additional bond with hydrogen can be made. Double bonds are stronger than single bonds and they give the fatty acid chain a ‘kink’. These kinks mean that the molecules can not pack together tightly, and the lipids are more fluid. This is why unsaturated fats tend to be liquid at room temperature, while saturated fats tend to be solid. Fatty acid chains with many double bonds are called poly-unsaturated fatty acids.

Cholesterol

Cholesterol is an organic chemical substance known as a sterol.  It is an important component in cell membranes. The major dietary sources of cholesterol include cheese, egg, pork, poultry, fish and shrimp. Cholesterol is carried through the body by proteins in the blood known as lipoproteins. A lipoprotein is any combination of lipid and protein.

Cholesterol is carried in the blood through the body by high density lipoprotein, low density lipoprotein and through triglycerides.

1. Low density lipoprotein (LDL): Low density lipoprotein transports cholesterol around the body. It has a higher proportion of cholesterol relative to protein. It is often known as “bad” cholesterol because higher levels of LDL are associated with heart disease.
2. High density lipoprotein (HDL): High density lipoprotein is the smallest of the lipoproteins. It has a high proportion of protein relative to cholesterol and is therefore often known as the “good” cholesterol. HDL transports cholesterol away from cells and to the liver where it is broken down or removed from the body as waste.

High levels of LDL can cause heart disease. Cholesterol builds up in blood vessels that carry blood from the heart to the tissues and organs of the body, called arteries. This leads to a hardening and narrowing of these vessels, which interferes with the transport of blood, and can potentially lead to a heart attack. The biggest contributor to the amount of cholesterol in your blood is the type of fats you eat. Saturated fats are less healthy than unsaturated fats as they increase the amount of LDL cholesterol in your blood.