How Does Fat Consumption Impact Cholesterol Levels?

Facts

Dec 8

Intro to Fats

The function of lipids is long-term energy storage and to absorb nutrients in the body. The fundamental structure of lipids is a single glycerol molecule with three fatty acid tails bonded to it. A fatty acid is a type of hydrocarbon chain, which means that there are only hydrogens and carbons in the structure and each carbon is bound together in a line, where each carbon has two hydrogens each. The bond between the glycerol and fatty acids is known as an ester linkage. The glycerol has a hydroxyl functional group that binds to the fatty acid tail’s hydroxyl group (-OH) on the alpha end. There are two ends of the fatty acid tail: the alpha end with a carboxyl group (COOH), and the opposite end is called the omega end and which has a methyl group (CH3). The ester linkage is created through an oxygen molecule with the process of dehydration synthesis, or the withdrawal of water to create a chemical reaction.

Saturated vs. Unsaturated Fats

Saturated Fats:

There is a single bond between each carbon atom in the hydrocarbon chain of the fatty acids
Has a straight fatty acid hydrocarbon chain
Turns solid at room temperature
Found in animals
When consumed, LDL cholesterol levels are increased

Unsaturated Fats:

There is at least one double bond between the carbon atom in the hydrocarbon chain
Kinked fatty acid tails because the double bond of two carbons
Turns into a liquid at room temperature
Found in plants, nuts, and fish
When consumed, HDL cholesterol levels are increased

What does that double bond “kink” mean?

Fats function to dictate the fluidity of the cell membrane. Saturated fats are able to really compress themselves into a tightly knit shape because they do not have any fatty acid kinks. This means that overconsumption of saturated fats can result in an abnormally tight cell membrane. This can impact what molecules are able to travel inside and outside the cell, which can harm the regulatory process. Whereas in unsaturated fats, the double-kink in the hydrocarbon chain allows for a little more wiggle room in the cell membrane because there it can’t make itself as small of a shape as a saturated fat

Understanding Cholesterol:

There are two types of cholesterol: LDL or low-density lipoprotein, and HDL or high-density lipoproteins. LDLs are commonly known as “bad” cholesterol. LDLs are bad because they can end up accumulating on in arteries. Evidently, the more plaque or substance blocking the artery, the harder the blood cells will have to push against the walls of the arteries. Therefore, LDLs can lead to high blood pressure along with several heart diseases and certain cancers. Saturated fats promote the growth of LDL by suppressing the LDL receptor proteins. LDL receptors are meant to properly allow and regulate LDL cholesterol into cells. However, because of the excess of saturated fats, and the tightly-knit structure inside the membrane’s phospholipid bilayer, the LDL cholesterol can’t bind to the receptor because there isn’t enough wiggle room. As LDL makes its way through arteries, instead of binding to the receptor, the excess amount of cholesterol starts to build up. Therefore, we can say that because saturated fats promote LDL cholesterol build-up, saturated fats themselves can lead to serious heart diseases.

HDL cholesterol undoes the work of LDLs. HDL cholesterol is very conducive to the absorption of other molecules. When in contact with an abnormal buildup of LDL cholesterol, HDL absorbed the LDL and freed the artery of excess cholesterol.