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A Closer Look At Cholesterol

Cholesterol crystalsCholesterol, at its most basic, is a waxy steroid metabolite found in the cell membranes and transported through the blood plasma of humans and animals. It is a structured component of membranes that are required to get proper membrane permeability and fluidity. Additionally, cholesterol is the key component that creates bile acids, and steroid hormones amongst several other things. The actual term comes from the Greek and wasn’t used in the traditional sense until the 18th century. Cholesterol can be explained in terms of what it is, or a basic overview, its function in the human body, how it is created, dietary sources, and metabolism as well as excretion. This substance is considered into two distinct components; LDL for bad cholesterol, and HDL for good cholesterol, and the two have distinct roles in the bigger picture.

Cholesterol is essential for all life and is synthesized from simpler substances found inside the body. For a person of average height and weight the typical cholesterol is about a gram per day and in the whole body it usually doesn’t exceed thirty five grams. The body compensates for food that we eat by reducing the amount of cholesterol synthesized. Excreted by the liver via the bile into the digestive tract, typically half of the excretion of cholesterol is reabsorbed and the intestinal tract knows what to do with it after that point.

LDL versus HDLThe liver is a key component in the excretion and management of this substance, but the function is what is most interesting. The function of this excretion is required for building and maintaining membranes managing to regulate membrane fluidity over a wide range of temperatures. At a microscopic level, the intracellular transport and cell signaling is helped incredibly by this substance and helps movements through the body. It has more recently been shown that in cell signaling and assisting the formation of lipid rafts in the plasma membrane, cholesterol is a key factor.

Egg yolksThe dietary sources containing cholesterol is somewhat easy to calculate. Animal fats are point number one of this substance. All foods containing animal fat contains this. Some have more than others, and in heavy doses can create plaque and adverse effects to the cardio vascular system. The highest level items are cheese, egg yolks, beef, pork, poultry, and shrimp. Breast milk also contains a large quantity of cholesterol. This substance is not present in plant based food sources unless they have been added through food preparation with animal fat of some kind. There are some exceptions though, like flax seeds, peanuts and others. These lower levels of cholesterol are similar but not as adverse in their effects to the human body.

Cholesterol is oxidized into a variety of bile acids, which turn into glycine, taurine and glucuronic acid or sulfate. The absorption rate is roughly ninety-five percent of the bile acids through the intestines. The remainder is lost through feces. The excretion and reabsorption bile acids forms the basis of enterohepatic circulation which is important to aiding digestion and absorption of fats.