Most of the messages we receive around cholesterol tend to be warning us about the risks of having too much cholesterol, and which foods to avoid to keep our levels as low as possible.
What you may be surprised to learn is that cholesterol is actually essential to human life. Cholesterol contributes to the production of bile in the liver, which is needed for fat breakdown in the stomach. It also serves as an essential part of cell and tissue regeneration, and perhaps most importantly, it is required for the production of most of our sex hormones such as oestrogen, progesterone and testosterone.
Cholesterol also plays a role in several neural pathways associated with behaviour and mood. Studies have shown that people with low cholesterol (yes, that’s right, I said low) show higher rates of anxiety, antisocial behaviour and mood disturbances. There are of course several factors that contribute to these psychological outcomes, so it is important to remember that cholesterol may just one of many contributing factors in this area of health.
There are two main types: LDL and HDL.
Low-density lipoprotein (LDL) cholesterol is known as the ‘bad’ cholesterol because when there is an excess of this type, the arteries can begin to harder and narrow – this is called atherosclerosis. The LDL cholesterol deposits plaque in the arteries, which attach to the artery walls, gradually causing narrowing and stiffening of the artery. This process can eventually cause blood clots to become blocked, resulting in a stroke or heart attack. Due to these negative health outcomes, LDL cholesterol levels should remain low.
High-density lipoprotein (HDL) cholesterol is protective for the cardiovascular system because it essentially does the opposite of LDL cholesterol. HDL cholesterol picks up the LDL cholesterol from the arteries and brings it back to liver to be broken down. Pretty cool right?
Basically, higher HDL cholesterol is protective against stroke and heart attack, while higher LDL is a risk factor.
Minimising your intake of trans fat and saturated fat is a great place to start. The saturated fat in butter, cheese, meat and cream can lead to higher LDL cholesterol, so these foods should be eaten in moderation (not excluded) to keep the saturated fat intake at a healthy level. Foods containing trans fats should be kept to an absolute minimum, as these are harmful fats that are synthetically made. Foods made with shortening, such as cakes and cookies, often contain trans fats, as do most fried foods and some margarines.
In order to boost your HDL levels, including regular sources of healthy fats is key. Extra virgin olive oil is a great source of monounsaturated fatty acids (healthy fats). Fibre found in whole grains, beans, legumes, fruit and vegetables are also great for reducing LDL cholesterol. Omega-3 fatty acids are very effective in reducing LDL cholesterol. These fats can be found in salmon, sardines, trout and flax seeds.
Lifestyle factors such as regular exercise, quitting smoking and reducing your stress levels are also very beneficial in improving cholesterol levels.
In summary, it is important to recognise the importance of cholesterol in our overall health and to understand the difference between the two main types of cholesterol. Aiming for lower LDL and higher HDL is far more protective against cardiovascular diseases than simply looking and the total amount of cholesterol in the blood!
Written By Esther Rijk, Dietitian