Unless you've been living in a cave for the past 10 years, you can't have failed to notice the amount of references in the media to cholesterol, and how we should all be working to lower the levels of cholesterol in our blood. While it's certainly dangerous to our health to have high cholesterol levels, it's important to understand that cholesterol is also an essential part of a healthy diet. Approximately 20% of the cholesterol in our bodies comes from the food that we eat, with the other 80% being produced in the body by the liver.
Cholesterol can be classed as both a steroid and a lipid. It naturally occurs in the brain, nerves, liver, blood and bile of vertebrates, including humans. For this reason, people who have high cholesterol and need to reduce their levels are advised to steer clear from meat and other animal food products.
With so much emphasis on cholesterol-free products, it's easy to become confused as to the role that cholesterol plays in a healthy diet. It's certainly true that many of us need to reduce our cholesterol levels, but it's also important to ensure that you have a good balance of this crucial substance in your body.
Cholesterol - what does it do?
Cholesterol is used by the body in a variety of different ways; the cells use cholesterol to build membranes, and it's also crucial in the formation of healthy sex hormones and as part of the digestive process. If, instead of a healthy diet, we have a tendency to take in an excessive amount of calories through sugary foods and saturated fats, we put our bodies under pressure to produce high levels of cholesterol. Stress can also play a role in the creation of cholesterol, as it’s the precursor of stress hormones.
The fluid levels in our membranes have a very small window of change in terms of retaining optimal function. Our cholesterol helps to regulate these fluids in our membranes; our bodies use cholesterol for stiffening membranes that are too loose, and remove cholesterol from membranes that are too rigid, in order to maintain the right level of fluidity.
Cholesterol is a vital ingredient in the production of steroid hormones, such as oestrogen, progesterone and testosterone. It's also used to manufacture adrenal corticosteroid hormones including aldosterone and cortisone, which regulates the kidneys water balance, and helps to synthesise glucose for the fight or flight response, respectively. Cortisone is also sometimes used in the medical profession in order to suppress inflammation. Another use for cholesterol is in the manufacture of Vitamin D, and it’s also the derivative substance for the production of bile acids.
Cholesterol is dispersed from the liver, via the bloodstream, to different tissues in the body - this is done with the help of special types of protein molecule called lipoproteins. This allows the body’s cells to take the cholesterol that they need, while any unused cholesterol gets carried back to the liver by other lipoproteins.
You may have heard of ‘bad cholesterol’ and ‘good cholesterol’; low density lipoproteins, or LDLs, are classed as bad cholesterol, while good cholesterol comes in the form of high density lipoproteins, or HDLs.
Bad cholesterol (LDLs) and good cholesterol (HDLs)
LDLs are the lipoproteins that transport cholesterol around the body, and are therefore weighty with this substance. HDL's are used by the body to remove any access cholesterol from the bloodstream and body tissues. After collecting this access, the HDLs travel back to the liver, where they deliver the cholesterol that they've collected, ready to be transported by the LDLs again.
In a healthy body and with a healthy diet, this process works in balance - but if you're ingesting high levels of cholesterol through the food that you eat, there may be too much cholesterol for the HDLs to work efficiently - and if that happens, the access cholesterol can stick to the walls of your arteries, putting you at greater risk of heart disease.
Over time, and with a poor diet, your LDL levels may become higher, while you may consecutively suffer from lower levels of HDLs. If this happens, it’s important to try and readdress this balance in order to reduce your risk of heart disease and a potential heart attack. This means that you will need to try and increase your HDL levels while simultaneously decreasing your levels of LDLs.
The problem is that eating food that’s high in cholesterol isn't the only way that we can suffer from increased levels of LDL. A diet that’s high in saturated fats can also increase the amount of bad cholesterol in your body, and sugar, alcohol and stress can also raise your natural cholesterol levels (the cholesterol that the body produces itself).
As you can see, it's vitally important to follow a healthy diet and reduce stress in order to ensure that we're not at risk of increasing our body’s bad cholesterol, or LDL, levels.
So in order to reduce your risk of heart disease, you should try not to eat too many animal products, or too much saturated fat, sugar or alcohol. It's also important not to be dependent on food products that claim to contain no, or low levels of, cholesterol; some of these products may contain high levels of saturated fats, so despite the food having no dietary cholesterol contained within it, the saturated fats can raise your natural cholesterol levels, which can still lead to a detrimental effect on your health.