This is the story that I shared on my Instagram stories for Mythbusting Monday. I’ve included some links and references for you at the end. Enjoy!
Welcome to the blog Mythbusters - this week’s topic was so huge, it needed a blog post to handle the information and share some important references and links for you.
Firstly, the basics. What is cholesterol?
Cholesterol is a fatty acid that is essential to life. It forms the walls of our cells, some hormones (like androgens) and vitamin D.
Cholesterol comes from two main sources. Firstly we manufacture it, through a series of enzymatic reactions mainly in the liver. Our bodies regulate cholesterol absorption through homeostasis - our bodies self-se-points. So if we eat more fatty acids and cholesterol, our own production should decrease. When levels get too low, we make more.
Dietary sources tend to come from meat, eggs, fish oil and butter. This has been a point of contention over the years whether or not we should eat a diet low in cholesterol - when eggs were not cool. This is a huge topic itself and I won’t go into it here.
Now being a fat, cholesterol can’t just cruise around in our blood. Imagine if you add oil to water - they don’t mix. Same with cholesterol in our blood. Cholesterol needs to be transported from the liver or the gut (or fatty tissues) packaged with proteins called ‘lipoporteins’
There are a number of types of lipoproteins: VLDL, LDL, IDL and HDL. I’m going to focus on two: HDL or high density lipoprotein also known as ‘good cholesterol’ and LDL or low-density lipoprotein, aka ‘bad cholesterol’
Let’s very quickly looks at HDL.
Low levels of HDL are associated with increased heart disease
HDL cholesterol protects our vessels through multiple ways including removing cholesterol from the vessel wall where it causes damage, reducing inflammation, calming down platelets and improving the way we use glucose.
HDL = Heroine.
Because LDL itself is a huge topic, I want to give you a bit of a summary here too:
We know that LDL is central to causing plaque and heart disease because of a combination of studies that show the higher the LDL, the more likely heart disease is
We also know that when we treat LDL cholesterol and make it go down (through medicines or through other means) that the risk of heart disease goes down
LDL is a small particle that easily gets into the walls of our vessels and causes plaques, damage, inflammation
LDL = villain
(And yes I know that simplification of LDL to bad and HDL to good is over simplification but I’m trying to distill complex topic to something digestible)
What causes high cholesterol? (And when I say hi cholesterol, I also mean high LDL and low HDL which is the perfect set-up for heart disease)
Some other medical condition (hypothyroidism) and some medications
Now saturated fats. High fat diets are back in vogue as the always do from time to time. Proponents say that fats are not responsible for disease and carbohydrates are. Unfortunately, there are two things wrong with that statement.
First, it’s not entirely true.
Secondly, trying to distill down to disease to blame one macronutrient is a vast oversimplification of the science. And it over simplifies the fact that humans eat food, not nutrients.
When it comes to fat in our diets, there is a lot of evidence that shows that saturated fatty acids are associated with increases in heart disease (found in meat etc). Unsaturated fatty acids seem to have some protective factors. Not all fats are created equal.
Fats in milk for example, although saturated, seem to be protective. And what may be worse than the saturated fat is what you replace it with in your diet. So if you cut out all saturated fat (hard to do) and replace it with say trans fats (very bad) then things don’t look good. Replacing saturated fat with polyunsaturated fats seems to reduce the risk of heart disease.
Now on to statins. Statins are medicines that stop our body from producing cholesterol by blocking one of the enzymes called HMG CoA Reductase. Previous cholesterol drugs blocked our gut uptake and weren’t as good. Statins also are anti-inflammatory, calm down platelets and have a number of other effects outside of lowing cholesterol.
There is a large amount of evidence to support the use of statins, but the benefits aren’t the same for everyone. For example, in elderly patients, they may not be as helpful as say in someone who has had a heart attack. Which is why saying ‘statins are bad’, blanket statement, doesn’t take into account everyone’s unique situation.
The other problem with statins is harm and this is where the media have played out a number of quite frankly, shitty stories scaremongering on statins.
Statins do have some side effects such as muscle soreness, liver enzyme rises and in rare cases muscle and liver damage. The risk of these are:
Serious liver issue 0.001%
Muscle soreness 10% (often easily treated by altering dose or changing statin)
Muscle damage <0.1%
Diabetes 0.2% per year (The diabetes one is tricky; lots of people who need statins can get diabetes anyway)
Incidentally my dad stopped his statin a few years ago because he read too many garbage stories on statins. He’s a smart guy, but he thought that the risks were much higher because of dramatisation in the media.
Most of the less serious side effects for statins can be alleviated by changing to another statin, reducing the dose or changing to another drug altogether. If it makes anyone feel any better, I would take a statin in a heartbeat if I had to. And just to lay it out there, I am not in bed with big pharma, the laws in Australia are so strict I’d lose my job if I even took a pen from them.
Statins should be started after consideration of an individual’s case with their own doctor AND in conjunction with lifestyle changes. Lifestyle changes can improve cholesterol but not usually as dramatically as a statin - lifestyle changes can be hard is one thing that causes that.
The first recommendation in the treatment of cholesterol guidelines is not take pills, but rather a healthy lifestyle is the cornerstone for all people.
All in all - cholesterol denialism is not based on sound science, and the evidence to show that a diet high in fats, especially saturated fatty acids is good for us does not exist. In fact, the opposite is probably true. The dietary guidelines of most countries promote a diet high in vegetables, fruits and wholegrain, low in saturated fats and these are sound.
Nutrition science is so complex and so anyone claiming to know everything about it is probably leading you astray. Science always evolves and that’s okay, it’s always good to improve. At the moment though, the safest bet is on cholesterol reduction. And statins are very important in the treatment and prevention of heart disease so if you ever need one (I hope you don’t) then please talk to your own doctor about your own individual situation.
https://sciencebasedmedicine.org/the-cholesterol-controversy/ - This is a great overview of the research behind cholesterol
Low-density lipoproteins cause atherosclerotic cardiovascular disease. 1. Evidence from genetic, epidemiologic, and clinical studies. A consensus statement from the European Atherosclerosis Society Consensus Panel.