Usually when we talk about cholesterol, we think about all the negative side effects it may have on our body.

It’s good to know that cholesterol also carries out a number of very beneficial roles in the body.

Let’s talk about some of the important functions of cholesterol.


Functions Of Cholesterol



Cholesterol forms part of the cell membrane building blocks


Cholesterol makes up part of each and every cell in the body. Cholesterol and phospholipids are two major lipids that make up cell membranes. Cell membranes make up the outer layer of cells, and act as gatekeepers.

All cell membranes are in part made from cholesterol, in fact some cell membranes comprise of 50% cholesterol according to The Cell: A Molecular Approach.

Cell membranes have a double layer of lipids called phospholipids. Phospholipids are lipids that have a phosphate molecule attached to them.

Cholesterol is essential in cell membranes for 3 main reasons:

  1. Cholesterol supports cell membranes, cholesterol is insoluble in water and is more rigid than surrounding molecules so it ensures that the cell membrane is structurally supported.

  2. Cholesterol keeps cell membranes fluid. Cholesterol has different effects on the fluidity of cell membranes depending on temperature. It ensures the cell membranes does not become too rigid or too fluid despite changing temperature

  3. Cholesterol is necessary in the construction of special parts of the cell called lipid rafts. Lipid rafts are thought to be involved in the transportation of specific proteins that help prevent the infiltration of certain pathogens such as viruses and bacteria.


Cholesterol produces key hormones


Cholesterol is a precursor for a number of essential steroid hormones.

In simpler terms, cholesterol is necessary for the formation of key hormones.

Examples of steroid hormones include: progestogens, glucocorticoids, mineralocorticoids, androgens, and estrogens.

Your body’s hormone-producing glands use cholesterol to make hormones such as estrogen, testosterone, cortisol and thyroid hormones.

Let’s take a look at some examples of how hormones are affected by cholesterol and how cholesterol impacts on your hormones:


1. Cholesterol and thyroid hormones


It has been shown that an underactive thyroid (hypothyroidism) and therefore a lower level of thyroid hormone production leads to an increase in circulating LDL cholesterol in the blood. It has also been shown that an overactive thyroid (hyperthyroidism) and therefore a higher level of thyroid hormone production may lead to a lower level of LDL cholesterol in the blood. This illustrates the importance of co-testing your thyroid hormones with your cholesterol levels.


2. Cholesterol and female sex hormones


Female hormones, most notably estrogen levels play a role in women’s cholesterol levels. When circulating estrogen levels rise in the blood, LDL cholesterol levels decline. When circulating estrogen levels decline in the blood, LDL cholesterol levels increase. This may explain why there is a higher chance of heart disease in post menopausal women, because estrogen begins to naturally decline with age which in turn leads to a higher volume of LDL cholesterol in the blood.

The connection between estrogen and LDL cholesterol has also been shown in men who are experiencing estrogen dominance, a condition in which estrogen levels are significantly higher than they should be in relation to testosterone levels.


3. Cholesterol and male sex hormones


Cholesterol and male sex hormones, most notably testosterone levels play a role in men’s LDL cholesterol levels. There are two primary examples which exemplify how declining testosterone levels affect LDL cholesterol.

As men age, their testosterone levels naturally decline, this process is often referred to as “andropause”. It has been shown that as testosterone levels decrease, LDL cholesterol begins to increase. This increases the risk of heart disease in men in a similar way it would to women.

Higher LDL cholesterol has also been shown in men who undergo androgen deprivation therapy (ADT), a therapy often used to lower testosterone in men with prostate cancer.


4. Cholesterol and cortisol


Cholesterol and cortisol affect one another through cause and effect. Cortisol, your stress hormone is released during periods when the body or mind feel under attack. If you are stressed for a prolonged period of time, excessive cortisol may be released into the blood.

This can have a number of harmful side effects on the body, one of them being the increase of LDL cholesterol in the blood.


There are two main reasons that this may happen:


  1. When the body goes into “fight or flight” mode, it may try to hold onto the resources it has at its disposal. One of these resources is body fat. This may explain why during times of stress, you may find it more difficult to lose weight, and therefore lower your cholesterol levels.

  2. If you are experiencing stress over a prolonged period of time, you may be more likely to comfort eat as a coping mechanism. Eating unhealthy foods may lead to weight gain and in turn an increased amount of LDL cholesterol in the blood.



Cholesterol helps to produce vitamin D


Cholesterol plays a role in the body’s production of essential vitamin D. We need a certain amount of cholesterol in our bodies and skin cells to ensure that vitamin D is produced when we are exposed to sunlight.

Vitamin D is processed in the liver and kidneys and is then circulated in the body for optimal physiological function.

A cause and effect relationship between cholesterol and vitamin D has been observed as a result of a study which showed that people with low levels of circulating vitamin D in the body tend to have high total cholesterol in the blood.

On the other hand, it has been shown that vitamin D supplements do not have an effect in lowering your cholesterol levels. Read one of our latest articles: 11 Tips To Reduce Cholesterol Without Medication.


Cholesterol plays a role in digestion


Cholesterol plays a role in digestion, due to the fact that it is an essential ingredient in the production of bile.

Bile is a substance that is produced in the liver and stored in the gallbladder. It is responsible for the breakdown and absorption of some nutrients into the body.

Bile is an essential substance to have in the body, especially for the breakdown and digestion of dietary fats.


Cholesterol affects other essential parts of your health. While it’s good to know that cholesterol does in fact have positive benefits on the body, but it also shows the importance of regularly checking your cholesterol levels. When was the last time you checked your cholesterol levels?


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Written by Hannah Kingston | Medically Reviewed by Dr. Susan O' Sullivan