Cholesterol: A Killer In Disguise?
Home / Health & Fitness / Articles / Cholesterol
A high level of cholesterol in your bloodstream is associated with a greater chance of you developing Coronary Heart Disease. This in turn increases the chances of you suffering a heart attack. Figures published by the Department of Health state that 2.3 million people in the UK are prescribed drugs to reduce the levels of cholesterol in their blood. This costs the NHS around £730 million each year and this figure is rising.
These cholesterol-reducing drugs are called Statins, which work by blocking production of the enzyme our bodies use to manufacture cholesterol. This process reduces the amount of cholesterol in our bloodstream. However the same enzyme would also produce Co-enzyme Q10 which is vital to maintain a healthy heart and muscles. CoQ10 is a very important anti-oxidant that helps protect our cells from damage by free radicals. (More on these later!) So by effectively blocking the production of CoQ10, statins may have an unintentionally detrimental effect on the health of the heart - the very organ they were trying to protect in the first place!
So you'll be pleased to hear that simple changes in lifestyle and diet can dramatically reduce the cholesterol levels in the blood, and thus reduce the risk of developing coronary heart disease without resorting to drugs to solve the problem for you. Read on...
So what is cholesterol?
The cholesterol molecule is pictured on the right, however from reading articles in the press or through advertising campaigns you may be forgiven for thinking that there are two types of cholesterol, the so-called Good and Bad varieties. However like a lot of food product advertising this is childishly inaccurate and in fact refers to the mechanism our bodies use to transport cholesterol via the bloodstream.
Our bodies produce special carrier molecules called Lipo-Proteins, and the two main types are Low Density Lipo-Proteins (LDL) and High Density Lipo-Proteins (HDL). The liver is responsible for the main production of cholesterol molecules by our bodies, and it is also charged with removing it from the bloodstream & excreting it. Our aforementioned LDL carriers remove cholesterol from the liver & pass it into the blood. If there is excess cholesterol in the blood there is more chance of clogging up the veins & arteries, so because of this the LDL carrier has become nicknamed as Bad cholesterol. On the other hand, our HDL carriers take cholesterol back to the liver so it can be excreted from the body in the form of bile acids, hence the nickname Good cholesterol.
Our bodies can manufacture cholesterol when required and it can also be obtained from our diet. Meat, eggs, dairy products and to a lesser extent seafood all contain cholesterol, whereas fruit & vegetables do not. It was once theorised that a diet containing lots of cholesterol-rich foods had a direct relation to the levels of cholesterol in the blood, however as Udo Erasmus points out in his book Fats That Heal, Fats That Kill, about 70% of people who live in the developed world have a regulatory system that allows their bodies to slow down the production of cholesterol if there is a high dietary intake. Interestingly scientists first developed this theory by feeding rabbits with large doses of cholesterol, and had seen blood cholesterol rise dramatically. What they seemed not take into account is that rabbits are vegetarian, so do not have the ability to cope with cholesterol in their diet! Fortunately it seems the majority of us humans can & do cope with a certain amount of cholesterol in our diets.
So if a large proportion of the population can self-regulate their blood cholesterol levels when their dietary cholesterol intake is high, how come blood cholesterol is reaching levels that can lead to Coronary Heart Disease?
Once again, diet plays a vital role in the amount of cholesterol the body actually produces. With a diet rich in sugars, saturated fats & refined carbohydrates (white bread/pasta/rice) the body is forced into making more cholesterol than it actually needs. When cells break down carbohydrates & fats they produce substances called 2-Carbon Acetates, and it is these that the body turns into cholesterol. An excess of acetates leads to an increase in cholesterol.
Alcohol also provides a rich source of acetates, however alcohol also has a much bigger impact on blood cholesterol levels. When we drink alcohol (especially in excessive amounts) the membranes that surround each cell become more fluid. To counteract this and to maintain an optimum level of fluidity each cell can produce cholesterol which it inserts into the membrane, helping to shore-up the cell wall, so to speak (pictured left). When alcohol levels drop there is no need for the extra supporting cholesterol, so it is removed and passed to the liver for excretion. As we have already discussed, this process raises the level of cholesterol in the bloodstream.
So with the potential problems that excess cholesterol can cause, you may be excused for thinking that we would all be better off without it. However the presence of cholesterol is vital for a number of reasons. Besides helping cell membranes maintain consistent fluidity, cholesterol also delivers the following functions:
- Precursor To Steroid Hormones: Cholesterol is used to make the sex hormones progesterone, oestrogen and testosterone. Also the hormones aldosterone, which is used to help regulate water retention, and cortisone which helps the body prepare for the fight or flight response.
- Vitamin D Production: With the help of sunlight, cholesterol in skin cells is converted into vitamin D. This vitamin is vital for strong bones as it helps them absorb calcium.
- Skin Protection: Cholesterol is secreted by skin cells and helps to prevent dehydration & damage from sun, wind & rain.
So how does cholesterol lead to a thickening of our arteries or increase the possibility of a heart attack?
These arguments all centre around the presence of so-called Free Radicals in our bodies. Free radicals are unstable atoms that can cause damage to other molecules in their vicinity. An increase of free radicals can be caused by smoking, excessive sun bathing, eating burnt or fried foods, strenuous exercise and air pollution such as traffic fumes. To help our bodies cope with these destructive atoms we need to arm ourselves with Anti-Oxidants which are molecules that help quench the free radicals. We can make certain anti-oxidants ourselves if we have the right vitamins and minerals, but our main source of anti-oxidants comes from eating a variety of fresh fruit and vegetables.
Free radicals can damage the walls of our arteries & veins leading to cholesterol becoming stuck in the cracks. The lipoprotein carriers can also become damaged and unable to move cholesterol around the bloodstream, leaving it to become embedded in blood vessel cell walls. Over a period of time this can lead to thickening of blood vessel walls, therefore a smaller area for blood to flow through and thus increased blood pressure (pictured above). In serious cases this can lead to heart attacks & death. Of course this process does not occur overnight, but obviously any diet that; (A) leads to an increased production of cholesterol and (B) has a poor intake of anti-oxidants can have serious consequences for the health of your heart, especially if combined with a lifestyle that increases your exposure to free radicals.
So what can you do to reduce your cholesterol levels and reduce your risk of suffering from heart disease?
As mentioned at the start of this article, a few simple changes in lifestyle & diet can tip the balance of blood cholesterol levels in your favour.
- If you smoke, stop. Do you really need to be told this one?
- Do not sunbathe excessively and try to avoid polluted places such as smoky pubs and busy roads.
- Exercise has many health benefits, and whilst free radicals are naturally produced as our body converts food to energy, excessive exercise over a long period of time can take a large toll on our bodies. As always, the key is to not overdo it.
- Regarding diet, it is best to keep your intake of refined carbohydrates & saturated fats to a minimum (essential fatty acids are not usually broken down into 2-carbon acetates as the body has much more important uses for them).
- Increasing your intake of essential fatty acids can reduce stickiness & clumping of blood platelets, helping to prevent clotting in arteries and keeping blood vessel cell walls flexible. This can help reduce hardening of the arteries.
- Eating a minimum of 5 portions of fresh fruit and vegetables each day will boost your intake of anti-oxidants and will also provide you with a good amount of fibre (see left sidebar for why this is important!)
So I hope the above gives you some good information as to why cholesterol plays such an important role in our bodies, and how with a little common sense you can easily control the levels within you. More next month, and if you have any questions in the meantime you know where I am...!
- Author: Stuart Cornock
- Sources: Patrick Holford 'The Optimum Nutrition Bible', Udo Erasmus 'Fats that Heal, Fats that Kill', Internet sources.
