Cholesterol: the good, the bad and the ugly
by Marisabelle Bonnici
Thanks to cholesterol's bad reputation, people are often surprised to learn that it's actually necessary for our existence. Yes, we are all aware of its role in promoting heart disease and excess cholesterol in the bloodstream is a key contributor to cardiac disease. However, most people do not know that our bodies produce cholesterol naturally. In essence, it isn't all good, nor all bad, so I often like referring to the different types of cholesterol we find in our blood as the good, the bad and the ugly.
What is cholesterol?
Cholesterol is a waxy white/yellowish substance generally produced by our liver. It is usually found in every single cell of our body and it forms an essential part of our cells' membranes. It is also used to make vitamin D, hormones (including testosterone and estrogen our major sex hormones), while it helps our liver make bile which is important for our digestive system.
Our body produces approximately 80% of the cholesterol we need to stay healthy and only around 20% comes from the foods you eat. As we grow older though, some of us end up with very high levels of cholesterol through several unhealthy lifestyle choices and this is when our doctor starts worrying.
What is happening to our body when we are told we have high cholesterol?
Your body starts having fatty deposits in your blood vessels. Eventually, these deposits will start growing, making it difficult for sufficient blood to flow through your arteries. Sometimes, those deposits can break suddenly and form a clot that causes a heart attack or stroke or even kidney damage.
High cholesterol can be genetic. In fact, we do sometimes encounter individuals in their early 20s and 30s who are already on cholesterol medication as their body tends to produce too much of it. It can also be a consequence of an unhealthy lifestyle. A healthy diet whereby you consume the right kind of food like these superfoods, exercising and sometimes taking medication can help reduce high cholesterol.
What are the symptoms of high cholesterol
High cholesterol has no symptoms. Like high blood pressure, it is a silent killer. The only way to detect whether your fats are in order is by having a blood test done.
When to see a doctor
You can either ask your doctor for a cholesterol screening test or you may visit a pharmacy since some also offer a point of care cholesterol testing where you can get the results within five minutes.
If your results are favourable, retesting is advised every five years for adults with no other risk factors, however, if your test results aren't within the desirable ranges, more frequent measurements are often recommended. The same applies if you have a family history of high cholesterol or heart disease, diabetes or high blood pressure or if you are a smoker.
Cholesterol comes in three forms:
We have two types of lipoproteins found in our body - these are the transporters that actually carry fat to and from cells. One is called low-density lipoprotein or LDL, while the other is high-density lipoprotein or HDL. Then we have Triglycerides - these are the most common type of fat in the body and they are known for storing excess energy from your diet. The amount of each type of cholesterol in your blood can be measured by a blood test.
High-density lipoprotein (HDL) is the "good," healthy kind of cholesterol. It transports excess cholesterol out of your arteries to your liver, which disposes of it from your body. HDL cholesterol is referred to as good cholesterol because it reduces the levels of bad cholesterol in our body. Higher HDL levels are linked to a reduced risk of heart attack and heart disease.
LDL (Low-Density Lipoprotein) is the "bad," unhealthy kind of cholesterol. If there is too much LDL cholesterol in the blood, it builds up in the walls of your arteries causing them to narrow and stiffen. This leads to an increased risk of angina, heart attacks and strokes amongst other conditions.
Triglycerides are what I refer to as the ugly kind of fat. We get this type of fat mostly from the food we eat. Your body also produces it when it converts excess calories, most especially when it converts carbohydrates to fat for storage. As with LDL, the higher the levels the more health risks you will have.
What makes HDL Cholesterol good?
As mentioned above, cholesterol isn't all bad. In fact, cholesterol is an essential fat and we need it for our bodies to function well. It provides stability in every cell of your body. To travel through the bloodstream, cholesterol has to be transported by carriers - it does not float around our blood at random. These carriers are called lipoproteins. Each lipoprotein has its own preferences for cholesterol and each acts differently with the cholesterol it carries.
Experts believe HDL cholesterol may act in a variety of helpful ways that tend to reduce the risk of heart disease. For example:
- HDL cholesterol removes LDL or "bad" cholesterol
- HDL transports LDL to the liver where it gets 'eliminated'
- HDL cholesterol acts as a maintenance crew for our blood vessel walls. Damage to the inner walls is the first step in the process of atherosclerosis, which eventually causes heart attacks and strokes
There are many reasons why some people have low HDL and others have high HDL. First and foremost it can be genetic - our genes predispose us to certain conditions despite our lifestyle in this case. Lifestyle choices also affect HDL levels. Smoking, excess weight, a sedentary lifestyle and high blood pressure tend to lower HDL and so does a diet high in refined carbohydrates like white bread and sugars. Medications such as beta blockers, anabolic steroids and benzodiazepines can also depress HDL.
Is high HDL Cholesterol always good?
Most of us believe that the higher the HDL level the better. In most people, this is true but some research shows that high HDL can sometimes be harmful or can be the result of an underlying condition.
It is interesting to note that most people will find that HDL cholesterol rarely increases to the point that it is considered 'too high'. Currently, there isn't an established upper limit for HDL cholesterol, while it will not naturally reach unhealthy high levels in people with standard cholesterol processing and metabolism. Yet, in rare cases, HDL cholesterol can become too high.
A recent study has shown that for patients who have previously suffered a heart attack, having high HDL can mean that the person is at a higher risk of further heart disease since the inflammation caused by the heart attack can activate certain genes leading to further heart disease.
High HDL is also linked to other conditions, including:
- thyroid disorders
- inflammatory diseases
- alcohol consumption
Sometimes cholesterol-controlling medications and natural supplements can also raise HDL levels. These are usually taken to lower LDL and overall cholesterol levels. Increasing HDL levels is usually a positive side effect in people who have low HDL levels as in most cases, it decreases their risk of developing cardiovascular disease.
How to increase your HDL cholesterol level
International cholesterol guidelines tend to focus on lowering high LDL levels first and in contrast, increasing patients' HDL is not generally considered essential. In fact, it's important to keep in mind that high HDL doesn't automatically cancel out high LDL and this is a determining factor when considering whether or not to start cholesterol medication.
That said, it is prudent to do what you can to boost your HDL, especially if it is very low. Changes in lifestyle should be first on your list since they do other wonderful things for the heart, bones, muscles and psyche and have no harmful side effects. They include:
- Exercising more - vigorous cardiovascular exercise is ideal for boosting HDL. This may include running, boxing, cycling and any exercise that boosts the heart's rate significantly but, of course, any extra exercise is better than none.
- Losing weight - reducing approximately 5% to 10% of your weight if you are overweight can raise HDL levels.
- Avoiding trans fats - these artificial fats — found in hard margarine, many baked goods and fried fast foods — lower HDL. Getting them out of your diet can improve both HDL and LDL levels.
- Controlling your blood pressure and blood sugar levels
- Cutting back on refined carbohydrates - switching from refined carbohydrates to whole grains and adding more protein to your diet is a good lifestyle modification to increase HDL.
- Stopping smoking - we all know smoking has a lot of negative effects on our health amongst which includes reducing our HDL levels.
- Moderating alcohol intake - drinking alcohol in moderation (no more than one drink a day for women, one to two for men) raises HDL.
Dangers of high LDL cholesterol
If your LDL cholesterol levels are too high, fat deposits can occur in your arteries. These deposits called plaque found on the walls of your blood vessels can harden and narrow the blood vessels. This is a condition called atherosclerosis. Stiff arteries will result in impaired blood flow, which means that your heart has to work much harder to push blood through the stiffened arteries. Over time, as plaque builds up in your arteries, more damage will occur to your cardiovascular system. For instance, impaired blood to your heart muscle means that not enough oxygen will reach your heart muscle which may result in frequent chest pains called angina. Angina is not a heart attack but it is considered a first warning that you're at risk for a heart attack. If left untreated, over time, the artery may continue becoming narrow which can eventually block fully the blood flow to your heart resulting in a heart attack.
If this blockage occurs in arteries close to the brain, cholesterol can also lead to strokes. A stroke can eventually lead to memory loss, impaired in movement, difficulty with swallowing, speech and other bodily functions. Plaque can also block the flow of blood to arteries that supply blood to your intestine, legs, feet, kidneys, liver and other vital organs. This is called peripheral arterial disease (PAD).
Furthermore, high blood cholesterol can also lead to other conditions such as Alzheimer's disease which is caused by 'sticky' deposits in the brain, while it can also result in the formation of Gallstones, which are extremely painful. All of the above are great reasons why you should get your blood work done regularly by your GP.
If you have high LDL and low HDL cholesterol levels, which is what we typically see when reviewing the majority of patients tests results, your doctor will probably focus on lowering your LDL cholesterol first. Medications known as statins are the most common treatment for high LDL cholesterol.
What causes high LDL cholesterol?
Our body is smarter than we think. It will naturally produce all the cholesterol it needs for it to function properly, but unfortunately, an unhealthy lifestyle is what generally causes the increase in cholesterol levels we need to worry about.
The following can negatively affect your cholesterol levels:
- An unhealthy diet
- Lack of physical activity
- Smoking or exposure to tobacco smoke
- Excess weight
- Drinking too much alcohol
- Stress levels
Other factors that result in high cholesterol:
- Old age
- High blood pressure
Heredity can play a role
Some people inherit genes from their parents that despite a healthy lifestyle will still result in high cholesterol levels. This is called familial hypercholesterolemia which can mean that a genetic predisposition can result in cardiac disease at a much younger age.
If you have high blood cholesterol, making lifestyle modifications is a great first step to lower your risk of heart disease and if these measures don't reduce your risk enough, your doctor may prescribe medications to help.
Some tips for those with high cholesterol levels
- Learn to read food labels since this will help you ensure that you are eating food which is actually healthy for you.
- Increase the intake of healthy fats in your diet. Monounsaturated fats like those in olive oil, almonds and avocados reduce the 'bad' LDL and increase the 'good' HDL.
- Avoid trans fats foods when 'partially hydrogenated' oil is listed as one of the ingredients. Both trans fats and partially hydrogenated fats will increase your LDL and decrease your HDL levels.
- Increase fibre intake in your diet. Fibre will ensure that our gut bacteria is at a healthy level, while these bacteria will remove the cholesterol from the body. Good sources include beans, peas, lentils, fruit and whole grains including oats.
- Add whey protein. Found in dairy products, whey protein may account for many of the health benefits attributed to dairy. Studies have shown that whey protein given as a supplement lowers both LDL cholesterol as well as blood pressure.
- Cook your food in a healthier way by steaming or grilling it instead of frying.
- Exercise is vital to reduce LDL and also increase HDL.
- Weight loss has been shown to reduce overall cholesterol levels.
- Reduce the amount of sugar and artificial sugar you consume as this has also been linked to high cholesterol levels.
- Smoking appears to increase LDL and decrease HDL, whilst it can interfere with the body's ability to send cholesterol back to the liver to be processed. Quitting smoking can reverse these effects.
- Keep alcohol intake to a minimum.
- Supplements such as psyllium husk and L-carnitine and fish oils and certain probiotics can help reduce cholesterol levels. These can many times be purchased over the counter but please consult your pharmacist or GP before buying any supplements.
Unfortunately, sometimes healthy lifestyle changes aren't enough to lower cholesterol levels. If after changing your lifestyle for six months your doctor recommends medication to help lower your cholesterol, take it as prescribed while continue with your lifestyle changes. These changes will help you keep your medication dose low and keep side effects resulting from this medication to a minimum.