What Is Cholesterol in the Body and Where Does It Come From?

Heather Campbell
 min read

What is cholesterol in the body?

What Is Cholesterol in the Body and Where Does It Come From?The exact role of cholesterol in your body is a very complex phenomenon.

As a general rule, 80% of cholesterol is created by our body. It has a bad reputation but it performs essential functions such as cell building and bile production. Cholesterol is also responsible for the production of vitamins and sex hormones such as progesterone, estrogen, and testosterone.

Read on to understand this essential body process and learn exactly what the difference between good and bad cholesterol is and how it ends up in your body.

What is cholesterol in the body? Introduction

Cholesterol is a fundamental building block in several processes that ensure our bodies function as they should.

For example, cholesterol is needed to produce cells, some hormones such as sex hormones, specific vitamins, and bile.

Despite its bad reputation, cholesterol does perform an essential function within our bodies.

Cholesterol is a colorless and oily substance. It belongs to the group of sterols, which are found in humans and animals, plants, bacteria, and even some fungi.

The sterols found in plants are called plant sterols or phytosterols.

Cholesterol is its counterpart from the animal kingdom and is thus the most common type of sterol in humans.

Since sterols are so widespread, one understand their importance.

Functions of cholesterol: Overview

Cell building

Cholesterol is primarily essential for building cell membranes. This layer seals the inside of a body cell from the outside.

Our bodies are made up of millions of these body cells, which all need a cell membrane.

Cholesterol is an essential building block of this cell membrane and, among other things, ensures that these cell membranes are flexible and fluid enough.

Production of bile

In addition, cholesterol plays a prominent role in the production of bile, which we need for our digestion.

Production of hormones and vitamins

The basic building block of all plant and animal sterols is the so-called sterol ring structure.

It is particularly useful for producing several vitamins and certain hormones:

  • Vitamin D
  • Cholesterol is also the basic building block for the development of steroid hormones.

One of the best known from that group of steroid hormones is the stress hormone cortisol, which impacts blood sugar levels and blood pressure, among other things.

The hormone aldosterone also belongs to this group of steroid hormones. Aldosterone is essential in regulating blood pressure through salt metabolism.

Finally, cholesterol is also essential for producing our sex hormones such as progesterone, estrogen, and testosterone.

These hormones and vitamins are found in our bodies only in very minute amounts. Thus, the amount of cholesterol required for this purpose is also minimal.

Cholesterol enters our bodies in 2 ways

There are 2 ways we get cholesterol into our bodies:

  1. About 80% is created by our body
  2. Only about 20% of cholesterol enters our body through our diet

Cholesterol made by our body

Contrary to popular belief, we do not get the vast majority of cholesterol into our bodies through our diet!

In fact, a large mass of cholesterol is produced by our liver. In addition, even smaller amounts of cholesterol are made in the adrenal glands, testes, and intestines.

Altogether, our body’s own cholesterol production accounts for about 80% of the total cholesterol levels we measure.

In other words, the body’s own cholesterol has the upper hand, and cholesterol through our diet only accounts for about 20% of the cholesterol in our bodies.

It is important to know that this cholesterol production in the liver is very strongly hereditary.

Cholesterol through our diet

Only 20% results from what we take in through our diet, so most cholesterol in our bodies is not due to our diet!

The body of a 154 lbs adult male contains about 30 to 40 grams of cholesterol.

In terms of proportion, it is as follows:

  • The liver makes an average of one gram or 1,000 mg (milligrams) of cholesterol daily.
  • The average dietary cholesterol intake is only 200 to 300 mg per day (or 0.2 to 0.3 grams per day).

Thus, we can influence or regulate a maximum of 20% of our cholesterol levels through diet alone. Beware: These are, of course, average values.

Tip: Get to know which foods help to lower cholesterol in our other article What to Eat to Lower Cholesterol? 3 Nutraceuticals (Functional Foods) in the Spotlight

People with downright dramatic or very high-fat diets who are taking in significantly more cholesterol through their diets will achieve a more significant effect through a modified diet.

And someone who already eats more or less healthily and with variety will have a limited effect at their fingertips by making additional adjustments to their diet.

The link between obesity and high cholesterol

There is almost no link between obesity and elevated cholesterol.

Even very lean people can have significantly elevated cholesterol levels, and obese people can have excellent cholesterol!

Related: Check out our other article to find out How to Treat High Cholesterol: Frequently Asked Questions

Cholesterol processes: Through food or through the liver

The way we get cholesterol into our bodies is a pretty complex process.

Exogenous process (through diet)

Cholesterol and fats absorbed with food go from the intestine to the liver and this is called the exogenous cycle.

On the way to the liver, much of the energy-rich fat (mainly triglycerides and free fatty acids and, to a lesser extent, cholesterol) is absorbed by fat and muscle tissue.

All the rest then ends up in the liver.

Endogenous process (via the liver)

The endogenous cycle begins in the liver, where fatty particles are produced that contain, in addition to cholesterol, energy-rich fats called triglycerides and free fatty acids.

Those particles are primarily released into the bloodstream between meals (as opposed to the exogenous cycle).

And in this way, those energy-rich fats get to the tissues that need them.

Because mainly energy-rich fats are delivered to the tissues, the proportion of cholesterol within these particles increases during the delivery pathway.

Some of those cholesterol-rich particles continue to circulate in the bloodstream, and some are reabsorbed in the liver.

The liver breaks down a certain amount daily. It converts them into bile salts that are removed from the body with bowel movement.

Impact of diet on cholesterol production

Since our bodies are responsible for most cholesterol production, you might think that diet doesn’t matter all that much. Not exactly.

Those who take in a lot of cholesterol through their daily meals send a signal to the body.

Your body monitors its intake of cholesterol and uses it as a feedback loop that will cause the liver to lower its own cholesterol production.

And this process also takes place in reverse.

In people who watch bun foods and eat less cholesterol-rich foods, the body will compensate by kicking up a gear and making slightly more cholesterol.

This is an additional reason that the effects of diet on cholesterol are somewhat limited.

What is cholesterol in the body? Conclusion

Cholesterol is a necessary basic building block in our bodies required to produce hormones, cell walls, bile, and vitamins.

Cholesterol belongs to the group of sterols that occur in humans and animals (cholesterol) and plants (plant sterols or phytosterols). The basic structure of cholesterol is the sterol ring.

The vast majority of cholesterol in our body (about 80%) we produce ourselves in our liver, and only 20% comes from our diet.

Cholesterol production in our liver is highly heritable. So you may be genetically predisposed to high cholesterol production in the liver.

Through our diet, we can, on average, influence or regulate at most 20% of our cholesterol levels:

  • People with a very high-fat diet that take in significantly more cholesterol will obtain a greater effect on cholesterol levels through a modified diet.
  • A person who already eats more or less healthily has only a limited effect at their fingertips by making additional adjustments to their diet.

Finally, there is almost no link between obesity and elevated cholesterol:

  • Very lean people may have significantly high cholesterol levels, while
  • Obese people can have cholesterol levels that are perfectly fine.
About Heather Campbell

As a nutritionist, my field of specialization is science-based nutritional advice but more importantly, it is my goal to share capturing and inspiring stories, examples and solutions which can help plus-size individuals overcome their specific difficulties. Read More