Three Myths You’ve Probably Heard About Cholesterol
5 minute read
Cholesterol is widely talked about when it comes to our health because its association with heart disease and stroke has been well studied.
When researchers first began suggesting that we keep an eye on our cholesterol levels in the 1980’s, many people began avoiding prawns and egg yolks out of fear that these foods would clog their arteries. Since then, we’ve come a long way, realising that we don’t need to necessarily avoid foods which contain cholesterol, but it’s still a good idea to routinely check that our blood cholesterol levels stay within a healthy range.
If you’re over the age of 45, or you have any other potential risk factors for cardiovascular disease (such as family history of cardiovascular disease or underlying health conditions), chances are that your doctor will have suggested that you get a blood lipid panel done on a routine basis. A typical blood lipid panel includes a test for total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides.
While a standard lipid panel can give you an idea of your risk of cardiovascular disease, what we’re beginning to discover is that actually there may be more to the story than what many of us have been told.
You may have learnt that HDL = ‘good’ and LDL = ‘bad’, therefore, if your total cholesterol or your LDL-cholesterol is high, it can be ‘cancelled out’ by either having lots of ‘good’ HDL-cholesterol, OR having a good ratio of total cholesterol to HDL-cholesterol.
Unfortunately, this formula may have been giving some of us a false sense of security (and some of us unnecessary panic), because there’s actually a little bit more nuance to it all, and this narrative doesn’t actually hold true in all scenarios.
So, let’s look at some common myths when it comes to cholesterol:
All cholesterol is bad
Cholesterol is needed by all cells in the body because it is a structural component of the cell’s plasma membranes. We also need cholesterol for the synthesis of hormones such as cortisol, testosterone and oestrogen, as well as bile. This means that we need cholesterol to support our adrenal health, mental health and our reproductive health. Cholesterol may also have a role in immunity, with HDL in particular having been discovered to have beneficial anti-inflammatory and antioxidant properties.
So, when you get a lipid panel done, whilst it’s good to have cholesterol scores towards the lower end of the reference ranges or even slightly below, if you are struggling with fatigue, depression, mood swings, frequent infections or fertility issues then it could be worth questioning whether your cholesterol levels may be too low, which could be the case if you have very low body fat levels, follow a strictly whole-foods vegan or very low fat diet, or have a malabsorption issue.
2. HDL cholesterol is the ‘good guy’
You may have thought you do not need to worry about having high total cholesterol or high LDL cholesterol if you also have high HDL cholesterol. This is because HDL is known as the lipoprotein which ‘cleans up’ excess cholesterol in the bloodstream and carries it back to the liver to be excreted out of the body.
However, there are actually 5 different subclasses of HDL, but only one of them is actually known to remove cholesterol from the bloodstream (known as HDL-2b)! This means that when we test HDL-cholesterol (HDL-C on our lab report), we’re measuring all 5 subclasses together and we cannot accurately tell how much of the ‘good’ HDL we actually have.
In fact, unless we’re already healthy (no other metabolic risk factors or health conditions), if HDL levels become too high, then it’s possible for the HDL particles to also become pro-inflammatory and atherogenic!
So, the cholesterol to HDL-C ratio is only a helpful indicator for people who are otherwise already healthy. In everyone else, HDL-C levels are more of a U-shaped curve in terms of risk for cardiovascular disease. They shouldn’t be too low, but too high isn’t a good thing either.
3. LDL cholesterol is the ‘bad guy’
LDL is the lipoprotein which delivers cholesterol from the liver to the rest of the body, in particular our brain, adrenal glands, testes/ovaries, and skeletal muscle. High levels of LDL-cholesterol (LDL-C) are linked to cardiovascular disease because LDL can begin to deposit cholesterol into the walls of our arteries and begin the formation of atherosclerotic plaques.
So yes - high levels of LDL-C ARE a red flag to watch out for!
However, similarly to HDL, LDL also comes in different types. There are 4 subclasses of LDL, but only LDL-3 and LDL-4 are known to be atherogenic because they are small enough to pass through blood vessel walls.
This means that it is possible to have high LDL-C that is actually nothing to be concerned about IF it happens to be that you don’t have high levels of LDL-3 and LDL-4.
LDL-C will typically increase with ageing, and it can also be higher due to genetic conditions, this doesn’t always mean that you are at risk for cardiovascular disease. You cannot expect your cholesterol levels to stay the same as they were when you were 21 by the time you are in your 50’s and older (even if you manage to stay lean, exercise, avoid smoking and eat a balanced diet) - but that doesn’t mean you are not healthy, it is simply a normal result of ageing.
How do we get a better assessment for cardiovascular disease risk from our blood tests?
Many doctors and health practitioners are beginning to recognise that we need a little bit more information than what a typical lipid profile tells us if we want to see the full picture of what’s going on with our cardiovascular health.
Next time you go to order a lipid profile test, if you are concerned about your risk for cardiovascular disease, ask to also have your Apo-A1 and Apo-B tested. Apo-A1 is the major protein component of HDL that is specifically known to have cardioprotective effects (cholesterol lowering), and Apo-B is the major protein component of LDL that is specifically known to be atherogenic (plaque forming). An Apo-A to Apo-B ratio will provide a more accurate and informative idea of your cardiovascular health than just testing LDL-C and HDL-C.
Summary
We need cholesterol to function, just not too much or we put ourselves at risk for cardiovascular disease! A standard lipid panel that includes HDL-C, LDL-C, total cholesterol and triglycerides gives us a starting point to guess where we are at in terms of our cardiovascular health, but it doesn’t provide the full picture and could even be misleading. If you are concerned about whether you’re at risk for cardiovascular disease OR if you have any other metabolic health concerns, you should also ask for your Apo-A1 and Apo-B to be tested to get a more accurate idea of whether you need to take action about your cholesterol levels.
If you would like to get a better understanding of your blood tests along with a personalised nutrition plan from a Registered Nutritionist to help you take action steps towards improving your health, you can organise a discovery call with Lauren.
