Episode 48 - show notes
- What is cholesterol - It is a waxy type of fat that is in every cell of our body and is essential to life.
- We even make our own cholesterol! Our body always makes sure there is enough around, our liver will make it if we are not eating enough cholesterol.
- Cholesterol comes from animal foods - When we eat animal products they contain cholesterol that we can then use in our body.
- LDL - Low-density lipoproteins, known as bad cholesterol, and the current dogma associates high LDL with a higher risk of heart disease.
- HDL - High density lipoproteins, known as the good cholesterol.
- Cholesterol blood tests - These include total cholesterol (less than 5.2), LDL (less than 2.6), HDL (higher than 1.5) and triglycerides (less than 1)
- Interpreting the cholesterol test results - It needs to be looked at a case by case basis. It is primary or secondary prevention? Other risk factors, such as medical history and smoking.
- LDL subfractions - Seven different particle sizes, categorised into large fluffy and small dense. Small dense are linked to increased risk of heart diseases. Can be tested in Australia but not covered by medicare.
- Article by Ken Sikaris - https://lowcarbdownunder.com.
- Associate Professor Ken Sikaris on YouTube - Cholesterol - When to Worry & Making Sense of LDL
- Use these directories to find a low carb educated doctor to help make individualised choices which are right for you - Diet Doctor or Low Carb Down Under
But what about my cholesterol?
Dr Mary Barson: (0:11) Hello, my lovely listeners. I'm Dr. Mary Barson.
Dr Lucy Burns: (0:15) And I'm Dr. Lucy Burns. Welcome to this episode of
Dr Mary Barson: (0:21) Real Health and Weight loss.
Dr Lucy Burns: (0:23) Good morning, lovely listeners. It's Dr. Lucy here. And we're back! The dynamic duo. I'm joined, of course, by my bestest doctor, Dr. Mary Barson and we have a ripper of a topic to talk to you about today. Mary gets to nerd out on some biochemistry and I get to learn and listen with open ears.
Dr Mary Barson: (0:51) Hi, Dr. Lucy, it's lovely to be back. I'm excited by today's topic, cholesterol. This is an extremely controversial topic, I would suggest and one that is incredibly pertinent I suppose to the low carb world. And I think there is an awful lot of confusion and concern when it comes to cholesterol, particularly when you and I tell people to eat real food, including real food that naturally contains cholesterol, you know, like meat and eggs, people can start to get a bit worried. So I'm happy to be here talking about this incredibly important topic. And yes, I will nerd out on the biochem. But I'll control myself.
Dr Lucy Burns: (1:42) Excellent. Well, I thought we'd start with you giving us a little biochem lesson on what exactly cholesterol is?
Dr Mary Barson: (1:49) Yeah, what is cholesterol? To be honest, I think that even quite a few health professionals might struggle to answer this question. So cholesterol is absolutely essential to life. It's a waxy type substance that is a bit like a fat, and it is in every single cell of our body. We absolutely need it. We would be extremely dead without it. So that's the first thing that I say: it's not something that is inherently bad, it's not like a dirty word. It's a naturally occurring molecule that is in every cell of our body and has a really integral part to play in our cell integrity. Every cell in our body is surrounded by a cell membrane, made up of fats. Very, very, very, very delicate, clever little structures our cells. And the cholesterol is an essential part of the scaffolding of the cell membrane, kind of the pins that keep it all together. So it's incredibly important for that. But that's not its only job. Cholesterol is incredibly important in hormone synthesis. All of our steroid hormones like oestrogen, testosterone, cortisol, and other hormones like vitamin D. We need cholesterol as a substrate to make all of these hormones - another reason why we'd be extremely dead if we didn't have cholesterol. It's also… Yeah, yeah we need it!
Dr Lucy Burns: (3:14) Ugh! Yeah! We don't want that. We don’t want to be extremely dead!
Dr Mary Barson: (3:17) Don’t be extremely dead. Accept cholesterol as a natural part of your natural being. We need cholesterol to create bile acids. Our liver breaks it down along with other fats and we need bile acids to be able to absorb our fat soluble vitamins, which is like vitamin A, vitamin D, vitamin E, vitamin K. It also has an incredibly important role in our brain health and our nerve health. So the formation of the myelin sheath that wrap around all of our nerves in our central nervous system and our peripheral nervous system that keep our nerves healthy, that enable them to be able to conduct properly, well cholesterol is a central part of that as well. There are other things that cholesterol does but they are just some of the main things. So that's it. It is incredibly important.
Dr Lucy Burns: (4:05) So I'm imagining with these myelin sheath, it's a bit like you know the plastic stuff that surrounds your cord and your charger.
Dr Mary Barson: (4:13) Absolutely, if you rip off the plastic covering on your charger, you know it doesn't work very well. And sparks can fly everywhere and you don't get particularly good conduction so the myelin sheath around our nerves is very very important. Cholesterol is so important in fact that your body makes sure that there's always enough of it around and we make it. We make cholesterol. Our incredibly clever livers - which is my favourite organ by far - will make cholesterol. If we don't get enough from our diet they'll just make some. If we're getting more from our diet, it usually makes less. So by and large, the actual level of cholesterol in our blood is fairly well controlled within a sort of a normal range. Because without it we're very dead.
Dr Lucy Burns: (4:59) Okay, so, walk me through this Mares, we eat some cholesterol. So it's animal products. Am I right in saying that? So you know, when you see the sticker on the avocado that says cholesterol free? Well, that's not cholesterol. They're not special avocados.
Dr Mary Barson: (5:14) Nope
Dr Lucy Burns: (5:14) They’re just normal.
Dr Mary Barson: (5:15) Yep Exactly.
Dr Lucy Burns: (5:15) So it's only in animal products.
Dr Mary Barson: (5:17) Yeah.
Dr Lucy Burns: (5:18) So what happens? We eat something.
Dr Mary Barson: (5:20) Yeah, so if we eat any kind of animal food, it's going to have animal cells in it, and it's going to have cholesterol. Plants have different types of sterols, but they don't have cholesterol. So animals are the ones that have cholesterols. Yes. And so well, what happens? So our body will then absorb it, and it finds its way into its blood via the chylomicrons. I'm actually not going to go into that. So we either get cholesterol when we eat it, or our liver makes it. But you know what, when doctors talk about cholesterol, “Your cholesterol is high”, “Let's check your cholesterol”, “I'm a bit worried about my cholesterol”, “I think I need to watch my cholesterol”, we're actually not talking about cholesterol, surprisingly enough. What we're actually talking about is the little protein packages in which cholesterol is transported around the body. So every single cell in your body needs cholesterol, your liver will make it or we get it from our diet. And it needs to be transported from the liver to the cells where it's needed for its vital functions. And because it's a fat, it can't be just in solution within the blood. Only water soluble things can be in solution in the blood. Anything that's fat soluble, our body needs to come up with a slightly clever way to transport it. And how it transports cholesterol, the waxy substance, is it packages it into lipoproteins, and it is these lipoproteins, which is a sort of a package of fat, cholesterol and protein all packaged together that transports fats and cholesterol around our body. These are what we measure when we do a cholesterol blood test. These are what we are concerned about when we're doing a cardiac risk assessment on someone. And the cholesterol, the two lipoprotein particles that we measure that we are primarily concerned with is cholesterol that's packaged into the low density lipoproteins, we call them LDLs for short. They contain a particular apolipoprotein B, and I'll come back to it. So that's the LDL, so the ones we're mostly concerned about, and also cholesterol packaged into the lipoproteins called high density lipoproteins (HDL) . And they've got the apolipoprotein A in them.
Dr Lucy Burns: (7:37) You know, when people talk about the good and the bad?
Dr Mary Barson: (7:41) Yes. Thank you. So, HDL, high density lipoproteins are generally called “good” because they are benign. People who have high levels of HDL cholesterol, it's generally associated with a lower risk of heart disease, right? Just note that I said associated and not caused. So high HDL is associated with lower risk of heart disease, which is awesome. And then it's the LDL. And we are taught and the current medical sort of dogma is that high LDL is associated with increased risk of heart disease. And the truth is that it's actually far more complicated than that. To say that LDL is bad, HDL good, “LDL bad - HDL good” is really overly simplistic, so simplistic to the point where it is actually kind of wrong. It's not to say that LDL isn't important, just that the truth and the reality is far more nuanced than I think a lot of people realise.
Dr Lucy Burns: (8:49) So if you go to the doctor, and you order a cholesterol test, you get told, here's your cholesterol number. And here's the breakdown of the good cholesterol and the bad cholesterol.
Dr Mary Barson: (9:02) Yeah, so typically, in Australia, you get a cholesterol blood test, it's a fasting blood test. And you get a few numbers. You get your total cholesterol levels out, which is not particularly, not necessarily all that meaningful, but you do get a total cholesterol level. You get a level of your LDL cholesterol, the low density lipoproteins, you get a measure of your high density lipoproteins, and usually the triglycerides, sort of the free fats in the bloods will be measured as well. And generally, total cholesterol of like 5.2 millimoles per litre or less is considered normal. LDL is around 2.6 millimoles per litre. And HDL is sort of the higher the better, but we'd like it to be above one millimole per litre at least, above 1.5 is probably better. And triglycerides. Well, they aren’t actually the most important measure. Less than 1.5 is considered normal, but really ideally you want them I would say less than one. So we're talking about normal and optimum. Okay, so you get this big blurt out of data and deciding what to do with that, what you do with this cholesterol reading, I think it needs to be done on an individual case by case basis. I'm going to hand over to you Lucy now to sort of talk about how we would go about intelligently doing a case by case individual sort of assessment on cholesterol and what people might want to know. Of course, first, I'd just like to say that this is not and it cannot be individualised medical advice, and it does not in any way, replace a conversation with your treating doctor. And Lucy and I, I'd say that you and I have pretty, I think we know a lot about this topic. And I'd say that we have pretty moderate views both ways. I would say, we don't have extreme opinions one way or the other.
Dr Lucy Burns: (10:54) No, and I think that's important to note. There are, like anything in the world, everything is a spectrum. And people get wedded to their view at one end of the spectrum or the other end. And you know, there's, as we've talked about, this happens in diet wars, where we talk about people who are wedded to the low fat lifestyle versus people that are wedded to a low carb lifestyle, you know, vegetarian versus carnivore or vegan versus carnivore. So these things are always going to cause some controversy. So, Mary, and I, yeah, we have what we would call an individualised and moderate approach. So some people believe that no one should be on a statin. And some people believe that everyone should be on a statin. And neither of us hold that opinion. So we then go, “Okay, well, how do you decide who should be on cholesterol medication and who shouldn't?” So our first thing to ask ourselves and our patient is, are we looking at something called primary prevention or secondary prevention? So what secondary prevention means is that if you have or have had a cardiovascular event, so you've had a heart attack, or you've had a stroke, you've got deficiency in your arteries in your legs, so peripheral vascular disease. There's something indicating that you already have cardiovascular disease, then you've passed primary prevention, you've got plaque already, and you're in the secondary prevention category. And the current guidelines and current evidence suggests that those people are likely to have a benefit of a statin. Now, again, we preface this with individual consultation with your doctor because, again, there are some people for whom statins cause problems with liver function or with their muscles. But that's the general broad brush stroke. If you've had an event you are likely to require and will benefit from a statin.
Dr Mary Barson: (13:02) Should we tell our listeners what a statin is? Just quickly?
Dr Lucy Burns: (13:05) Yeah, yeah. So a statin is just the standard cholesterol medication called statin because they go with words like this: simvastatin, rosuvastatin.
Dr Mary Barson: (13:17) Atorvastatin
Dr Lucy Burns: (13:19) Atorvastatin, yes, thank you. They're too long to say. So statin. There's some other cholesterol lowering medications as well, but not nearly as widely prescribed as the statins. And the statin is, I guess, the one that is controversial. So then we go, “Okay, what if you haven't had a heart attack, then does that mean you’re primary?” And the answer is actually, possibly not. Because you may have underlying plaque, underlying cardiovascular disease, but have not yet had an event, you would still be considered secondary prevention. So an event is, as I said, a heart attack or a stroke. So you might be at home, and you've got some underlying disease in there, doesn't bother you at the moment, but it will. So how do you tell if you're one of those people? And that's where we would often order something called a calcium score. Again, it's not a perfect test, but it gives us some indication. Other people might do a carotid artery ultrasound. It's a more nuanced test as well to look at the thickness of the carotid artery. But both of those tests will give you some clue as to whether you've got any underlying disease. If you come back with a calcium score of zero, then the chances of you having a future event in the next 10 years are really low. Not zero, but low. If your number is above 99, so above 100, then the chances of you having an event are much higher, and we would consider that cardiovascular disease. And then we've got the grey zone of the one to 100 and some of that depends a little bit on your age. So if you’re only say 45, and you've got a number of say 20, then that's actually pretty high. Because your body's gotta last you another 50 years. And the trajectory of having a calcium score of 20, when you're already 45 means that you're going to end up with a calcium score in the hundreds. Whereas if you were 80 years old, and you had a calcium score of 20, well, then that's, again, not such a big deal. So this is why we talk about nuancing and actually, you can't just give absolute numbers.
(15:39) So then we would be looking at primary prevention. So we've done the secondary prevention, and you know, we agree that a statin is the most likely thing that is going to help you. Primary prevention means that you have no cardiovascular disease. You might have a calcium score of zero, or you may not know it. And what we want to do is look at, well, what are all of the things that combine to cause cardiovascular disease? Because remember, there's not just one thing. It's not just cholesterol. There's a whole pile of things that kind of all coalesced together to then cause cardiovascular disease. For a long time, the primary focus has been on cholesterol, largely because there were medications available to treat it. But it is not the only thing. And it's not the most important thing. It is one of the things.
(16:36) So the other things: smoking, definitely. You know, it's really interesting. Sometimes I have people, I'm sure you do too Mares, who come in, and they want to know all about their cholesterol, and they don't want to take a statin but they’re smoking. That by far and away outweighs any risk of cholesterol. So, you know, we've got to be really mindful that we actually have all the foundations right as well before you make a decision on what you want to do. So smoking is number one. Well, not the number one, but one of the number one factors. Type two diabetes, another one. A highly atherogenic condition, particularly when it's not well controlled. So again, if you've got uncontrolled type two diabetes, your body is going to be laying down plaque like there's no tomorrow. It just does. There can be other inflammatory conditions that have probably not had a lot of airplay, if you like. And certainly Mary and I talk a lot about stress as an inflammatory condition. We talk a lot about not, not just stress, you know, people go, “Oh, stress is just, you know, mental health, it's in your brain.” No, there is a physiological response in your body that causes hormones and neurotransmitters to be released that damage your body. So it's not as simple as just, you know, managing your stress so that you don't worry. It's managing your stress so that you can look after your body.
(18:06) And then we talk about high blood pressure or hypertension. And I guess, you know, our favourite thing is insulin. And insulin is most definitely a contributor to plaque development, stiffening of the arteries, and cardio metabolic dysfunction. So, looking at all of these is really important before you make a decision on what you want to do. You can't just look at them in isolation, and then go “Well, you know, nobody, no one should be on a statin” or “Everyone should be on it”. It doesn't work like that.
Dr Mary Barson: (18:39) Yep, absolutely. The truth is always somewhere in the middle. And each individual person's truth is going to be different depending on their own individual circumstances. As low carb doctors or doctors who advocate low carb, real food, we find ourselves talking about cholesterol a lot. Yeah, purely because, you know, by advocating real food, including animal real foods, we're telling people to eat cholesterol. And I didn't mention before how diet can affect your cholesterol levels. So our bodies will regulate cholesterol levels to a degree. If you eat less, they'll make more. If you eat more, they'll make less, but diet can impact people's cholesterol levels, sometimes significantly. The majority of people that we see who go on a low carb, real food diet, most of them their benign HDL levels go up, nearly always the triglyceride levels go down, which is a really strong indicator that metabolic health is improving. And then the LDL, that mixture of good and bad, either kind of often stays the same or sometimes it goes up and sometimes it goes up a lot. And we've got a few ways to measure LDLs which are an important part of the individualised risk stratification and I'll hand you back over to Lucy for that.
Dr Lucy Burns: (19:56) Yeah, so I think it's really important to recognise that when we're doing a blood test, we measure total cholesterol. And then the LDL, we don't actually measure that, when that's taken to a lab, they don't measure it. It's a mathematical equation where they take, they can measure the HDL levels, and then they put it into a computer, and that spits out what they think your LDL levels are. So it's not an absolute measure. But interestingly, LDL has lots of what we call subfractions. So small types, there's actually seven different subfractions of LDL. And what those subfractions represent is the size of the LDL particles. So some of them are quite big. And they're often referred to as “large fluffy” because that's basically what they look like. And some of them are quite small, and they're referred to as “small dense”. And they're numbered. LDL 1 and 2 are both considered to be large Fluffies. And then 3, 4, 5, 6, and 7 are small dense. Now the small dense are much more damaging to your artery walls than the big fluffies. In fact, the big fluffies don't seem to be associated with atherogenesis at all. The small dense become oxidised and you know, I'm always imagining things, so large, fluffy, I'm imagining like sort of clouds just floating through the sky, and small, dense are like angry ball bearings, pinging into your artery walls. So we don't really want a lot of those, that's for sure.
(21:33) And so you can actually get that measured, it is a test that's available in Australia, it's not on Medicare, so it will cost you an out of pocket expense. And it's roughly depending on where you go around $200. It's the same with the calcium artery score. It's not on Medicare, it's done at a radiology clinic, but there is no Medicare rebate. And it’s also - depending on where you go - somewhere between $140 and $240. So these are tests that are not without a cost to the individual, but they can provide helpful information for people that are undecided as to what they should do. You know, some people are going, “Right! Well, you know, I've smoked and I've got type two diabetes and my cholesterol is 7.8, I probably should go on a statin?” The answer is yes, probably should, if you're not changing your diet and stopping smoking and all of those things. But the majority of people that we see are people that are doing low carb that maybe have lost significant weight, 20 or 25 kilos, their cholesterol was maybe 5.5. And now it's eight. And they go, “What am I going to do? Because you know it shot up.” And this is where an LDL subtraction can be really helpful to help you with a decision on what you should do about it.
Dr Mary Barson: (22:49) Yes, all in that really the nuanced truth, individualised assessment, and what you and I call “shared decision making”. There's no absolutes, you've got to decide what's right for you with the best medical advice that you can find.
Dr Lucy Burns: (23:05) Absolutely. And I think when we spend quite a bit of time in Facebook groups, from time to time people will post their cholesterol results and other people go, “Don't worry about it,” you know, “It's all fine.” It's actually not. It may not be fine, is what I would say. I would really caution people against taking advice about cholesterol and its management from Facebook groups and lay people because again, it's quite nuanced, and really needs to be an individual conversation.
Dr Mary Barson: (23:33) Yes. This is a pretty meaty topic, like this is complicated and there's a lot!
Dr Lucy Burns: (23:38) Did you see the pun there?
Dr Mary Barson: (23:41) That's right, certainly not a planty topic generally. I love eating plants, don't get me wrong. So if you want to learn more about this, I think we’ll put a link to some fabulous YouTube videos by an Australian pathologist, Dr. Ken Sikaris who has done some fantastic lectures which are available on the Low Carb Down Under YouTube channel. And I think that if you want to, if you really want to dive into this a bit more, that would be a really great place to start. And if you're on a low carb diet and you're confused about your cholesterol, then you can find doctors and physicians who have an interest in low carbohydrate diets throughout wherever you are in the world. And good resources to go to for this are dietdoctor.com has got a doctor's directory. And if you're in Australia, Low Carb Down Under also has a doctor's directory where you could find a doctor near you.
Dr Lucy Burns:: (24:38) Wonderful. All right, lovelies, I’m exhausted after that enormous topic. I'm in the middle of writing a blog about it, which will come out at some stage with some paper links for people that want to, you know, have a look at what the research that's been done, which is out there. But that'll come out in the next week or two. So I feel like signing off like the Two Ronnies. Well it’s goodnight from me!
Dr Mary Barson: (25:00) And it’s goodnight from me!
Dr Lucy Burns: (25:02) Yes! Bye now for everybody.
Dr Lucy Burns: (25:13) So my lovely listeners that ends this episode of Real Health and Weight Loss. I'm Dr. Lucy Burns
Dr Mary Barson: (25:21) and I'm Dr. Mary Barson. We’re from Real Life Medicine. To contact us, please visit https://www.rlmedicine.com.
Dr Lucy Burns: (25:32) And until next time, thanks for listening
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