this is one of the big myths that actually cutting out your fat reduces your cholesterol is nonsense if you were to say to me Jonathan how should I reduce my cholesterol level I would start by saying start eating fat Dr Sarah Berry is a world leader in large- scale human nutritional studies associate professor in nutrition at Kings College London and chief scientist at Zoe do we need cholesterol to survive it's something that's actually necessary for us we need it to make many different hormones vitamin D vile acids that are essential for the absorption of fat it's a component of every cell membrane without cholesterol we would be in a little bit of trouble 40% of people struggle with high cholesterol in the US and the UK which is an incredibly High number what can people do the good news is Jonathan diet changes cholesterol really quickly you can actually reduce your cholesterol by about 30% welcome to Zoe science and nutrition where World leading scientists explain how their research can improve your health Sarah thanks for joining me today pleasure thanks for having me back always wonderful and this one I think is going to be really fascinating because we get so many questions about it it's quite complicated and I know you're going to walk us through it to start with are you ready for the quick CH round of questions I'm ready and raring to go Jonathan on this one let's jump straight in is all cholesterol bad no do we need cholesterol to survive yes could too much bad cholesterol put me at risk for heart disease yes can the composition of your gut microbiome affect cholesterol levels yes could the right diet improve your cholesterol as much as medication yes and I know how cautious you are so that I'm impressed with that what's the most surprising thing do you think about cholesterol so I'm going to be greedy Jonathan and ask for two surprises here so the first surprise is that following a High healthy fat diet can actually improve your cholesterol and the second surprise is that following a high carbohydrate diet can actually make your cholesterol worse if you love The Zoe science and nutrition podcast please do us a huge favor and join the 26.7% of viewers who hit the Subscribe button you're doing so really helps because the bigger the channel gets the more people we reach with health advice that could change their lives so please hit subscribe thank you when the podcast team told me before the show how many people struggle with high cholesterol I was shocked apparently that's 40% of people in the US and the UK which is an incredibly High number and I think people who've listened to the podcast often know that like I have my own story about this that my father was diagnosed with high cholesterol um you know when he was very young we were in the States was a long time ago now and as a result he was um asked to go on this very very lowfat very high carbohydrate diet and it's interesting hearing what you uh say because that's sort of almost the opposite of what he were saying he was told because of this high cholesterol he mustn't eat any fats and he should eat as many carbohydrates as possible so I know that for him it's had a big impact on how he eats and I think for many many listeners this is one of the things about their health that they first get this indication about from visiting a doctor really feel like they have to go and change this diet they tend to get this very specific advice still in many cases to reduce fat a lot of people are really interested but it's also really confusing there's different sorts of cholesterol which I can never remember um and we're all being told we should lower it but it feels like the advice all feels like contradictory are you going to be able to like step us through this and give us some clarity I'm going to try and step you through this Jonathan I normally spend several hours teaching this to our students so I'm going to try and condense it as much as I can amazing well could you start at the beginning what is cholesterol so cholesterol is a type of lipid so it's a type of fat that circulates in our blood and that we can also eat as well and it's a waxy kind of substance and it's something that's actually necessary for us it plays a really important role in our body so we need it to uh make many different hormones we need it to to make vitamin D we need it to make bile acids that are essential for the absorption of fat and actually it's a component of every cell membrane in our bodies every single cell has yes has cholesterol so without cholesterol we would be in a little bit of trouble and so if I said in fact total we have to have it we wouldn't live without it yeah and that's why our body makes it you know our bodies are so clever so we don't make things that are bad for us just for the fun of it it's where these natural processes become a little bit disbalanced it's just where the problem comes in but it cholesterol is an essential part of our normal physiological functioning and when we often hear about cholesterol we also hear about it being in food we can eat um is that the same cholesterol or is that something different so it's slightly different but more importantly the way it impacts our health is very very different and so what we know is that dietary cholesterol to the cholesterol that we eat that you know it's found in many foods but for example we might think of some foods as being very high like eggs actually has very minimal impact on the cholesterol that circulates in our blood got it so it's not just the cholesterol in my blood is a result of the food that I eat no so if cholesterol is like necessary and it's floating around inside our bodies I guess my obvious question is what's it doing in our blood because that's where I think the doctors are measuring it and getting concerned and why is some of it considered bad yeah so we know that there's some type of cholesterol which we call LDL cholesterol is bad for us and we know there's some type of cholesterol which we call HDL cholesterol is good for us but as always Jonathan it's not quite so simple as that when we talk about LDL cholesterol and HDL cholesterol we're actually talking about the packages that the cholesterol is in so LDL cholesterol stands for or low density lipoprotein so that's the kind of package that it's in it's the parcel that it's in HDL cholesterol basically refers to cholesterol that's packaged in a high density lipoprotein parcel so you've got these two different Parcels but they actually contain the same type of cholesterol but it's how they're packaged and where it becomes really interesting is the label so the address label that's put on these packages is where actually it becomes really interesting in relation to disease so how does this fit with what we eat because you know one thing I would have thought listening to this is well if I'm worried about my cholesterol I just won't eat any fat so I can't have any fat in my body so I'm going to be really healthy but you just said at the beginning actually if you eat certain sort of fats your cholesterol might get better and you also said if you didn't eat any fat and you just ate carbs it could get worse so how does that fit with this good and bad so this is one this is one of the big myths that actually cutting out your fat reduces your cholesterol it's nonsense and the fact that it's still a myth out there is really blooming irritating so let's de debunk that what we want to do is we want to reduce our LDL cholesterol we want to reduce the cholesterol that's circulating in these bad particles what we want to ideally do is increase our HDL cholesterol so the cholesterol that's circulating in these good part particles and the reason we want to do that very simply put is because the cholesterol that's packaged in LDL is the the cholesterol that is circulating in our blood and delivered to our periphal tissues it's delivered to um you know along Our arteries where it can be actually taken up into the arterial wall and it can then cause atherosclerosis bad that's not its purpose is not to get stuck in the Ary walls no so it purpose isn't to get stuck in the artery walls its purpose is to be there available for cells and all these other things might going to my fingertip and then by accident you know it's got stuck in my wall and it slowly starts to build up this blockage that I've heard yeah imagine like a pipe that's become really furred with hard water for example you know in London we we have this problem and Sarah that's the LDL particles which are causing that like furring up of the of the arteries so the LDL particles have a particular label on them which is called the appal lipoprotein B label so it's got like this address label saying that the receptors on the lining of our blood vessels recognize that an aables it to be um uh cross over into the lining of our blood vessels because of this address label uh as a way of describing it called appal protein B it's then taken up by the lining of the blood vessels over time this causes this atherosclerosis so this furring um which causes the narrowing of the blood vessels um and over time you can get um you know plaque formation these can become unstable these can then burst and that's when you get a blockage which causes a heart attack so that's clearly bad you definitely don't want that and that's all coming back to this amount of LDL in our in our blood yes so it's for it's about how much LDL there is circulating in our blood how long it's circulating in our blood the really good news is that diet can have a huge impact on the amount and the duration that LDL is circulating it can impact how much LDL we're producing it can impact how quickly we actually take LDL and remove it from the circulation as well I definitely want to get into that for certain and so we're definitely going to talk about actionable ways you can do this before we get there could you talk a bit about the HDL as well because I know that when like I see my doctor he talks about the HDL being good third and so a high number somehow being positive it's not just this like LDL number that he's at least telling me that I should worry about yeah so that's correct so um htl is the particle that carries the cholesterol away from the periphery away from our blood vessels back to our liver so quite a simple explanation but I think it's the best way to explain it so you've got LDL that's basically taking the cholesterol and putting it where we don't want to put it it's delivering that parcel to the wrong address um and then you've got the HDL then redelivering it back to the right address and so that's sort of sucking it effectively sort of putting a a label on it you're saying in a blood so it's going to go back to its original point in the in the liver and you get it out of the bloodstream because there's more than you need yes in simple terms yes that's what it's doing so we often talk about it in terms of reverse cholesterol transport that it's taking it back what we know though now is that the Focus that we had 5 10 years ago on increasing our HDL cholesterol that there's many nuances to this about kind of uh the sorts of particles the HDL is circulating in the size of these particles and lots of other things that I don't want to kind of get too technical on today but the summary of that is that we know now that whilst yes we do want high levels of HDL cholesterol actually what's far more important is to focus on our levels of LDL cholesterol and so if we have high levels of LDL cholesterol and have high levels of HDL cholesterol we shouldn't be complacent thinking oh it's fine because my HDL is high actually what's really important is to bring that LDL cholesterol level down we know that for every 1 M mool increase in LDL cholesterol you significantly increase your risk of cardiovascular disease over 10 years by about 25% so that's quite big that does sound very big 25% is obviously a huge increase in risk and can you help me to understand how the how food fits into this story because you know I was definitely brought up as a child with this idea that your cholesterol was high because you'd like eat an egg that had lots of cholesterol in it and I know we've done a a podcast on that you said that's not true you know when you eat the egg you break it down but you've also said that you know when you eat fat like that fat does go into your blood so how does that fit into this story of LDL and I think again like this sort of really amazing answer to your question our question saying that you could actually eat some fats that would reduce your cholesterol which sounds crazy help us to understand okay so I think I'd first like to spend a minute just set setting the record straight on dietary cholesterol we have done a podcast I know on this uh before but just to summarize for people who haven't listened to that we now know that dietary cholesterol so the cholesterol that's in our food for example eggs does not increase our circulating level of cholesterol obviously I always have to caveat this Jonathan if you're consuming 30 eggs a day then it will have an impact but at normal typical levels of intake dietary cholesterol does not negatively impact our circulating cholesterol most people are getting less than 300 milligrams of cholesterol a day and below that it's not going to have any meaningful impact so you can have one to two eggs a day and not impact your cholesterol what does impact our cholesterol is actually not dietary cholesterol but it's other dietary components the biggest dietary component that impacts our cholesterol is fat but not in the way that you think it can actually have a huge favorable effect on our cholesterol a favorable effect on our cholesterol yes if you were to say to me Jonathan how should I reduce my cholesterol level I would start by saying start eating fat but I would say start eating the right type of fat so I'm guessing you're not going to tell me that I should just eat ice cream and butter no I have a feeling that or cakes or lots of other things so we know that there's lots of different foods nutrients that can impact our cholesterol and I think there's a a kind of dietary pattern that has been studied quite a lot called the portfolio diet and I often use this as a really nice way of explaining how powerful diet can be in impacting our cholesterol levels and most most importantly those LDL cholesterol levels because I really want us to focus on those rather than so much on the HDL given how strongly linked LDL cholesterol is with cardiovascular disease so the portfolio diet is a portfolio of different dietary components it includes having phytosterols we can pick up on this it includes having soluble fiber like betag glucon it includes having um plant-based proteins and it also includes having nuts and seeds so it's those four main components and this is largely because the effect of that those components have on how we process cholesterol and how we also remove cholesterol from the circulation but the single most potent effect that we can have is by increasing our dietary fat intake to increase the amount of polyunsaturated fatty acids that we include in our diet if we combine all of those four components that I've just said from the portfolio diet you can actually reduce your cholesterol by about 30% that's huge that's the kind of level of reduction that you'd get from a statim now to follow the portfolio diet is quite difficult to have the right amounts of all of these different components is quite challenging from a normal diet and this is why I think dietary fat is a really nice simple single strategy that we can Implement to reduce our cholesterol just want I just want to make sure I've taken away the takeaway here which is that by by increasing the right fats that you eat you can actually lower your cholesterol levels yes so I think the takeaway here is that there's multiple different ways we can reduce our cholesterol there's multiple different foods and multiple different nutrients and one of the components of the portfolio diet and one of the key single strategies in addition is to increase the amount of fat we're having from healthy fat sources and that can significantly reduce our bad LDL cholesterol and Sarah why is it that people have higher levels of of LDL so you know if we all start at really healthy levels because saying we have to have some you're describing in order to to live like what is it that means that living you know in you know developed countries it seems as though that's a sort of standard you sort of expect many many people like 40% we talked about earlier getting these test results saying it's too high what what's going on there so there's lots of different reasons and it varies from one person to the next person so we know that there are some gen gentic components to this we know that there's some quite serious genetic uh components such as familial hyp cholesterolemia where people can have cholesterol from birth very high you know in the region of you know for example 12 mm per ler the these people often less treated will not live into adulthood fortunately they can be treated with statins and so it's not so much of a problem now we also know that there's lots of other small genetic variations that can can impact how efficient we are at removing cholesterol and a really key component of this is the LDL receptor the LDL receptor is a receptor that sits on our liver and it's what removes the cholesterol from circulation for it to be recycled for different uses and so many of the reasons that some people compared to other people have high cholesterol is because they might have slight changes in how this LDL receptors working and it's also the reason why diet can have an impact on LDL cholesterol because it can impact the LDL receptor so we've got genetic components we've got dietary components that mainly act through the ald receptor but also some other areas but we also know that lifestyle can impact our cholesterol levels so we know for example excessive alcohol we know that living with obesity um can also impact as well we know that inactivity can also impact cholesterol levels so are they higher now than they would have been a few hundred years ago that's tricky one to answer because we are so good at measuring cholesterol now so people over a certain age will have regular lipid panel tests which measures cholesterol along with some other blood lipids and people are put on to statins which you know are very effective at lowering cholesterol if it's above a certain level so because of that cholesterol is kept in check but we know that cholesterol in terms of how it's increased by diet is more of a problem now because we are consuming a kind of diet that is not favorable for our CL saying the diet is making it worse but on the other hand there's this huge number of people on statins which are sort of keeping it under absolutely under control and you answered a question early on that I'd love to come back to about the gut microbiome is there any evidence that that is linked to cholesterol yeah so we have evidence from our own Zoe predict studies and there's a paper that we published in nature medicine in 2021 where we looked in our zoedic one study at a thousand individuals and we found a very close association with the microbiome composition and the different levels of cholesterol and we saw that specific species could actually be quite predictive of our cholesterol levels whether it be our LDL cholesterol our HDL cholesterol but also many other hundreds of lipoprotein particles are circulating that for someone like myself that studied lipus for ages is incredibly exciting I won't bore you with it we also see different species associated differentially with that so we actually developed a microbiome signature and this signature clearly separates species that are associated with favorable measures of cholesterol so I higher HDL lower LDL and some of these other particles and then ones are associated with unfavorable measures of cholesterol there's also randomized control trials where people are given probiotics for example probiotic supplements and you see that not always but most of the time these probiotics can lower cholesterol as well and we also starting to understand some of the mechanisms it's not fully understood yet but we know that there's particular chemicals that are produced in particular enzymes that are produced by gut bacteria that impact how we metabolize cholesterol I'm thinking do I risk it and I'm going to go for it I'm going to I'm going to push one level more complicated here because I know that as well as this LDL and HDL measure that we've talked about that there are a number of other measures that you're really interested in and that you talk a lot about when you're doing your own studies and looking at other studies can I start with this one called Appo B which I know um you know it's starting to be used I understand in some clinical test but it's not generally the first thing you get from a physician is it real does it matter what's the difference between that and and this ldr okay it's real it matters but I need to give you a little bit of a physiology lesson to explain why go for it okay so what happens when we eat fat when we eat fat it's packaged into special uh Parcels we call these lipoprotein particles and it gets given a label it gets given a label called apoe okay we also produce fat by our liver so the fat that circulates in our blood doesn't just come from the fat that we eat our liver is continuously producing fat when the liver produces fat it also packages it into these nice particles called liid proteins and it also gets a stamp label on it called apolipoprotein B so what happens is is you have circulating in your blood whether you're fasted or whether you've just eaten loads of these uh particles that have an address label on it called apolipoprotein B okay these at the beginning tend to be really rich in triglycerides so triglycerides are the main source of dietary fat they're the main way that fat is produced in the liver what happens is is as it circulates in your blood gradually you remove the triglycerides from these lipoprotein particles with the apob label and you remove them because you know your muscles want them for energy you know Etc what you end up with is you end up with quite a small particle that still got the apoia dress label on it but it becomes very cholesterol rich and doesn't have much triglycerides and that is the LDL the low density lip protein particle because it's tiny that's why it's called low density it's a low density particle and it's got that Appo label on it we know that all of those lipoproteins that have this address label called aoon aren't very good for us okay the reason they're not very good for us is because it's the Appo so it's the address label that actually our blood vessels recognize it's not the cholesterol in the LDL it's the label so that's why I refer to at this beginning as kind of the address label so the Appo is the address label saying hey please take me to the blood vessels so that I can enter the blood vessels fur them up and cause you a bit of a problem that's the byproduct of them them sort of hanging around for too long yes so if we're eating a healthy diet then what's happening is our LDL receptor is you know happy as anything and it's removing these Apper lipoprotein B particles okay and that's happening in your liver so they're on the surface of the liver yes and it's removing the appoin B particles in a timely manner however if it's not working very well which could be like I said through genetics through poor diet or po poor lifestyle then these apolipoprotein B particles are sticking around for a lot longer when they stick around for a lot longer they're in the form mainly of the LDL appal protein B particles so that's why we can think of LDL cholesterol as a proxy for apolipoprotein B the more direct risk is actually the amount of this Appo B that you have y and so measuring the Appo directly would be more accurate measure of sort of your risk than than the ldr correct so why don't we just all measure aob when we see the doctor it's more expensive and it's harder to do it involves quite specialist techniques so I measure appal lipoprotein B in my research in fact I measure the 200 different types of lipoproteins that can circulate which I would love to tell you about all of them but you're going to fall to sleep within a minute and they will tell us something slightly different but the apolipoprotein B is we know the single most important predictor of cardiovascular disease in relation to cholesterol but LDL is very cheap very simple very quick and easy to measure every Hospital lab can measure it in minutes that's why most people have LDL measured it's still really important we mustn't lose sight of the fact that actually LDL cholesterol is a problem it's just that in an Ideal World J would measure apob and I know that people are increasingly talking about apob but most of the evidence that we have out there shows you know as long as you're measuring or trying to reduce LDL then if you had a high LDL you're likely to have an high and two so they're they're like different measures but they're pointing in the same direction this is just a more accurate one which is why you've convinced us to measure it on many many thousands of people doing Zoe in the next year as as part of this big new study that is why we're measuring on thousands of people to look at how following the Zoe program impacts a whole host of different Health measures and Appo is one of the ones that I know you know it is a lot more expensive for us to do it we're doing as part of our research but it's because I believe that it tells us that little bit more and gives us more insight but we're also measuring Jonathan about 30 other lipo proteins as well in 2022 we took a huge risk we put our reputation on the line to prove that Zoey membership could improve the health of millions our team commissioned a randomized controll trial it's the most rigorous test that science has to offer which means you commit to sharing your findings good or bad the results of this study have just been published in nature medicine which is basically the Oscars of the Science World and these results show Zoe to be more effective in improving Health than government advice participants doing Zoey saw larger reductions in blood fat body weight and waist size they had better blood sugar control and saw an increase in their good bacteria crucially those doing Zoe also felt better they were twice as likely to report improved mood and feeling less hungry and four times more likely to report better sleep and more energy compared with a control group results like these are why more than 100,000 members trust Zoe to help them make smarter food choices each day to achieve their health goals so we give Zoe a try the first step is easy take our free quiz to find out what Zoe membership could do for you simply go to zoe.com podcast okay back to the show there are probably like a 100,000 or more listeners right now who are saying hang on like Sarah help me to understand what happened when I did my initial test when I became a member of Zoe and you talk about something called triglycerides and you measure it over time how does that fit into this story which I think for most people is really saying I'm worried about my cholesterol and I'm worried about what I should eat okay so let's step back to that physiology lesson I gave you about five minutes ago and if you remember I said when you eat dietary fat you eat it in the form of triglycerides and it gets packaged into these lipoproteins they get the Appo addess label put on them and then circulating our blood triglycerides are slowly removed and you end up with this LDL Appo parcel and so just to check you know if I so if I eat a piece of cheese y you're saying that once I chew that and swallow it goes into my blood as something called bits of triglyceride yes so when you eat food and you eat fat 98% of the fat that you're eating is in the form of triglycerides the other 2% is in the form of cholesterol phospholipids but it's the uh dietary fat is basically triglycerides it's also triglycerides that the liver is constantly making that are also packaged into these uh proteins what we know is that as well as the amount of circulating LDL cholesterol in your blood we also know how much triglyceride is circulating is quite important now the liver is constantly producing triglycerides and you can measure that in a fasting triglyceride measure so when you go to the doctor and have a standard lipid panel you'll have a measure of your total cholesterol HDL LDL cholesterol and also triglycerides but what we now know is that the extend to which your triglycerides increase after you have a high fat meal is also important in terms of your disease risk so what happens when you eat a high-fat meal you have an increase in circulating triglycerides because the fat in the meal is are triglycerides so it increases the triglycerides that are circulating they Peak about 4 hours to 5 hours after you've had the meal and then they return Baseline about 8 hours considering we consume many meals over the day you actually spend very little of your time in this fasted State given that it takes about eight hours to clear the fat so one of the things that we look at when we're looking at blood fat control with our zo test in addition to looking at LDL cholesterol which we look at as part of this test to look at how well your blood kind of fat control is we also look at how high your triglycerides become and how long they take to return to Baseline and this is important because we know that people that have elevated levels of triglycerides after a meal have increased risk of cardiovascular disease and the reason is is because it affects these kind of lipoprotein particles that we've talked about and in a very simple way it creates in the longterm LDL particles that we know are more arthrogenic so they're more prone uh to causing AOS sclerosis or furring of the artery and so what our test does is it combines both this postrel this postmeal triglyceride measure as well as looking at the very traditional LDL cholesterol measure to make sure I i' I've got that Sarah you're saying that we sort of measure this response in your blood after you eat this you know standardized meal and that in the same way that you've been describing that for your body to be healthy it needs to be able to clear away this LDL and not have it hang around you're sort of measuring this same thing with this big input of fat from your diet and you're saying well if your body can't clear that away then you start to have all the same sort of negative effects that you're describing with just having high LDL all all the time whereas if your body is functioning well your your liver is sort of going to clear this away and you're going to see that actually even though you did eat you know all of that cheese or whatever it is it's sort of pulling it back to this low level that your body is meant to be running at yeah I think that it's important to say that it's too slightly different mechanisms so what's happening with your LDL cholesterol that we've talked about a few minutes ago versus what's happening with the change in triglycerides that happens after you have a meal it's two slightly different mechanisms but it it all is in the end increasing our risk of cardiovascular disease and all of it can be modified By Di in this case the benefit of the the focus on the triglycerides that's actually what happens with the food and so you know if so if you're trying to understand what happens is I eat um food like should I be eating a high fat diet or less you're actually able to sort of measure directly what's going on inside your blood as a result yes and this is where I think it gets interesting of how changing the type of fat that we eat depending on your cholesterol levels depending on this postmeal triglyceride increase can actually have quite a big impact you know a brilliant transition I would love after like a pretty complicated explanation of what's going on because this is obviously quite complex let's start to talk about actionable advice so let's say somebody's listening to this and they're like that's great you've explained to me like that this is important that there are these risks what can people do if they're worried about their high cholesterol so this is a good news you can do a lot that's PR news and the great news is is that there is so much evidence for just how beneficial diet can be in lowering your cholesterol and lowering your LDL your appalatin B levels so what I would start with is I would start by thinking about the type of fat we're eating and so this is where I would caution anyone to change to a lowfat diet because they have high cholesterol don't do that and I think that's radical for lots of people I've had this discussion with members of my family who are still being given Like official advice saying you know you have this high cholesterol you should eat a lowfat diet so I just want to say this really clearly if you have high cholesterol should you switch to a lowfat diet no however and Jonathan there's always a however you need to make sure you're eating the right types of fat this is really important so whilst I think that people should follow a moderate fat diet I don't think people should go to a lowfat diet I think what's really important to say is it has to be from the right types of fat it has to be from poly and monounsaturated fat sources not from saturated fat sources and this is where there's overwhelming evidence that adding polyunsaturated fat fatty acids to your diet and these are the kind of fats that are found in seed oils are found in many different uh plant-based products many different nuts and seeds for example actually have a huge impact on lowering our LDL cholesterol so just by increasing your intake of polyunsaturated fatti acids you can reduce your LDL cholesterol this is why evidence shows again from my own research if you add nuts to someone's diet you can significantly reduce cholesterol by 5 to 10% just by adding nuts into the diet obviously it's instead of what we're assuming we're adding nuts in replace of unfavorable fats we always have to remember that what are we displacing in order to add them in and what about animal fats because I feel like what I was always always like well you know you've got to eat less red meat part of the that's because that but that is full of fat but that's that's bad fat so saturated fat we know has a cholesteral raising effect saturated fat is one of the most potent factors in our diet that raises cholesterol increases our cholesterol and so what else are the key things maybe just to understand also apart from red meat is there anything else you definitely should be eating less of so this is where I want to do a caveat again is not all saturated fat is equal actually in terms of how it impacts our cholesterol and this is why we need to really be taking a food first approach and this is something that we do at zo this is something I've spent a lot of time in the work I've done at zo developing our fat scores for foods is thinking not just about the type of fat but thinking about the food that is in and so we know that as a whole saturated Fat's bad for cholesterol P stop but we know that we need to worry about some saturated fats more than other saturated fats so saturated fat from processed red meats for example saturated fat from other red meats saturated fat from some Dairy not all Dairy so for example butter we know yes it increases our LDL or bad cholesterol what we know though is that there are some saturated fats that don't seem to have this negative effect and this is because of the cleverness that the amazing food Matrix of the structure that these fats are found in so fermented dairy such as cheese such as yogurt for example we know did not have a cholesterol raising effect so I know traditionally you've often told me this Jonathan that I know you know for example your father was told no more cheese you know you've got high cholesterol definitely no cheese I think you should that was like you know was one of the worst things you could possibly eat and you know 15 years ago this is what I was teaching the students that we have to get people reducing their saturated fat intake from reducing red meat reducing Dairy but actually formenta Dairy which is the chees which is the the yogurt actually doesn't have a cholesterol raising effect I'm not saying that we should gorge on cheese please let's cave at that it's not the primary thing that you're worrying about and so what my father did was like as result of like cutting out all this fat was eat way more carbs so we like eat lots of white bread and rice and things like this you know we talked elsewhere about how that's in general not great for your health does it have any impact on cholesterol yeah and I get to go back to the physiology lesson to tell you why so when you eat lots and lots of refined carbohydrates they're very rapidly absorbed these are things like white rice white bread um sugar uh Etc uh the kind of carbohydrates you get in these very heavily processed types of foods that we're eating far too much of now what happens is as they're delivered to the liver and then if you're eating them in excess I your body doesn't need them at that immediate point in time for energy they're converted then in the liver into triglycerides which are released if you remember what I said earlier in these Parcels that contain that appal lipoprotein B label on them basically I'm eating my carbohydrate I'm eating my lowfat diet it goes into my liver my liver says oh I've got all the carbohydrate that I need I the sugar and it then turns it into fat and pushes it into my blood BL in the exactly the same way as you described to me would have happened if I'd eaten a piece of cheese is that um or the net result is I've got this the net result is I was avoiding trying I was trying to avoid getting fat in my blood and all that's happened is my body has basically said ah you know I'm not getting enough fat in my blood so I'm just going to swap this over is that yes that's correct there going to be an awful lot of listeners feeling like I followed all of this advice from my doctor and the government about like having to eat low fat and hang on a minute telling me that my body just went and sort of did this anyway and had to give up the stuff I wanted to eat some reason to be a little frustrated by this I guess if you're following that advice for sure and so what happens is is then you've got these fats being released from the liver that's ultimately come from the carbohydrate they tend to be slightly high in saturated in particular mon unsaturated fatty acids as well and we know that saturated fats the reason as well they're bad f is because they downregulate this receptor which is the receptor that I've told you now a few times Jonathan if you were paying attention is the receptor that's on the liver that's responsible for removing cholesterol from our bloodstream okay so having saturated fat reduces the activity of that LDL receptor which is why saturated fat is bad for us because it's preventing the LDL cholesterol being removed so Sarah I feel like one of your worst students clearly I can see you saying you're going to fail the exam so what you're saying is if you're eating like red meat and Pro process meats and things like this um that have these saturated fats they're actually affecting my liver so it's suddenly doing a worse job of getting rid of the ldr yes and if you're having excess refined carbohydrates that are churning out saturated fat from the liver like the french fries with my steak yes okay yeah love that then what's also happening is you're reducing the LDL receptor activity because of that so you're kind of having a a double impact on then preventing the LDL from being removed Converse to this if you're having a high polyunsaturated fat diet then you upregulate the LDL receptor so what happens is is you're actually kind of sucking out more of this LDL and you're removing it more quickly so it's interesting a lot of this is about sort of making your liver work either better for you or worse for you depending upon the sorts of foods that you're eating yes I mean there's some other kind of things going on as well but this is kind of yeah the main thing and this is why actually if you increase the amount of fat you're having from these healthy sources so particularly from polyunsaturated fats but also some from monounsaturated fats but it's primarily the polyunsaturated fats that have this very potent effect on the LDL receptor you're going to reduce your LDL cholesterol quite significantly and this is why you know all of the evidence shows that people following a high polyunsaturated fat diet reduce their risk of cardiovascular disease by 10 20 30% and what about um foods that say low fat on the label because again this is one of the big things that um you know lots of people even today I'll be sort of given that advice as a way to try and navigate to um like a better diet for their cholesterol so I'm always cautious of any label that says low no or reduced CU what's been taken out or rather what's been added in in order to create a food that still functions in the same way when it says low no or reduced fat actually has a really important role for food not just because it's important for our bodies but actually it's what carries the flavor and the texture of food so I don't know if you've ever tried like low fat cheese or you know low fat it just doesn't taste the same it's the fat that gives it that beautiful kind of mouth feel and flavor and so in order to retain some of the pleasure of a food when you take the the fat out we're going to have to add lots of stuff to it and a lot of the stuff that's added to it firstly we don't know how it impacts our health but secondly what tends to happen is you're creating a food that's very high in these unfavorable types of carbohydrates so they sort of put in lots of sugar to compensate for taking out the fat for example I mean it depends on the type of food but often yes they they're often less healthy for us I do think Jonathan while we talk about carbohydrates it's really important not to demonize all of them because we know that whole Gray carbohydrates so if we think of whole grain bread for example we know that whole grains actually do have a beneficial effect in terms of our cholesterol so whilst I'm very Pro increasing the types of healthy fats in our diet we shouldn't do it at the expense of whole grains we must do it at the expense of these refined kind of white carbohydrates so you're just to make sure that I'm picked up that right you're saying it's not like all carbohydrates are bad for your LDL you're talking about these ones that are highly processed that can be or that just get turned you know like a potato or something gets turned into sugar in your blood really fast because then it's like your body's going to end up saying ah there's too much of this and I'm going to start creating fats and or store it in my fat yeah absolutely we know that if you increase your whole grain intake you can reduce your cholesterol levels we also know if you increase your fiber intake you can significantly reduce your cholesterol levels and fiber is one of these really important components of that portfolio diet that I mentioned particularly something called soluble fiber so many people will have heard of something called beta glucans I don't know if you've heard of that go on Sarah many people who you hang out with will have heard of beta glucans um I'm gonna I'm going to be the voice of many of our listeners saying beta what okay so beta glucan is a type of soluble fibers you've got two different types of fiber you've got soluble fiber insoluble fiber soluble fiber such as betag glucans that's found in oats but there's other soluble fiber found for example in legumes you know beans that sort of things pulses which is why they're so good as well for for our cholesterol these particular types of fiber can significantly reduce our cholesterol as well so having a decent amount of those can reduce our cholesterol and is that back to helping feed the right sort of um uh bacteria in our gut or we just don't really know why this is happening so we know that with soluble fiber the reason that it's beneficial is because actually it changes how we absorb cholesterol so we know a very there's a very distinct mechanism for that um and um but we know that insoluble fiber which is the fiber that does reach our gut that improves our cholesterol via the gut microbiome and so adding oats for example daily to our diet but I'd have to caution that with a massive it needs to be the right kind of Oats increases our beta glucan to the extent that therefore you can reduce your cholesterol but I would caution against having the kind of Oats that are are heavily refined against that we also know that there's other dietary changes we can make as well as reducing our refined carbohydrates as well as increasing our our fat healthy fat intake and the other that's often talked about is adding sterols and stanols to our diet and I haven't seen them in the grocery store last time I checked so they're actually part of every plant that we eat okay um and they act a little bit in the same way as to soluble fiber so kind of preventing the absorption of cholesterol however you have to have a certain amount of them you have to have about 2 g a day in order for it to be beneficial it's very difficult to get that on a plant-based diet you might get near to that but it's actually quite difficult even if you're on a fully plant-based diet you can buy products that contain these and these are your sterile and stanel kind of shot drinks that you get so you might have heard of like Pro Flor proactive Etc and so to get the ired amount you do need to really be buying these kind of products they're very expensive um and so for someone that is really concerned about their cholesterol I might often suggest they try these but I would say it's a starting point actually increase the amount of polyunsaturated fats in your diet I feel like that's a natural transition you've gone from food to something that's starting to feel like a supplement that's moving then to Medicine we had many many questions about statins um and so I'd love to sort of wrap up with that many people will either be thinking about taking them offered them or on them what are your thoughts so I need to caveat that as I'm often cave atting with that I'm not a medical doctor and I don't think I'm comfortable making a decision you know on whether someone should or shouldn't go on stattin I think it's something that you need to do in consultation with your clinician I think you need to look at what your current cholesteral level is as well as your overall cardiovascular disease risk is I think the evidence for or their effectiveness is overwhelming that's one thing I'll say from a kind of research perspective it's undoubtedly they reduce your cholesterol I do think for people that don't have excessively high cholesterol that they could start by looking at their diet given that we know that diet can have such a big impact on cholesterol so I would suggest if someone was to ask me what's my personal view but please this is not um a medical opinion that look at your diet first can you increase your polyunsaturated fat intake can you increase your fiber intake can you reduce your your refined carbohydrate intake you know can you increase the amount of legumes you're having beans pulses Etc and try that for a few weeks and see what happens the good news is Jonathan diet changes cholesterol really quickly we see a change in cholesterol after about 10 days when people are following a a a kind of diet that reduces cholesterol within two weeks you see quite a big change within a month you've seen a huge change so you can make these changes and then go back to your GP and see a month later has it significantly reduced your cholesterol if it's still alarmingly high that's when I think you need to continue that discussion about statins with Zoe the program involves small changes you know that accumulate over time because we know that making small changes are the changes that are going to stick so if you're making small changes that you progressively add to over time then I would suggest waiting two to three months till you go back to check if you are going all out and this is what we do in our studies then you will see it quite quickly but the reason I'm emphasizing how quick it is is because I think it's a really good motivational factor to say look you can quickly change it and I think a really important point to make as well Jonathan is that it's the duration over the years at which your LDL cholesterol is elevated that's important in terms of cardiovascular disease risk so I said earlier that if you reduce your LDL cholesterol by 1 M over 10 years you reduce your risk by 25% if you reduce it over 50 years you reduce it by 50% what we want to be doing is making sure there's less time that you have with an elevated LDL cholesterol that's really helpful Zara um and of course I can imagine the team back at zo saying make clear that Zoe is not for the treatment of any disease yeah and I think one last point I do want to make sure we say join this podcast given that we are doing a lot of research in this area of menopause I would really quickly like to say that you do see a change in cholesterol levels whether you're Perry or postmenopausal so we see in our own data from our zo predict studies that postmenopausal women have a sudden rapid increase in their LDL cholesterol increases by about 25% compared to if you're 25% increase yes compared to if you're premenopausal now some of that is a natural effect of Aging okay as you age your cholesterol increases irrespective of your diet but what we know is that um men are on a certain trajectory that their LDL cholesterol is increasing a little bit each year women are increasing a little bit each year what's fascinating and and we've published research on this as you know Jonathan is soon as you hit the menopause suddenly your trajectory changes you actually overtake men as women in your LDL cholesterol levels and this is because we know that estrogen which which is what you lose during the menopause is a really strong activator of that LDL receptor so we know why this happens and so this is when diet becomes even more important but the good news is again is that you can somewhat try and reduce that increase that you have in cholesterol postmenopausally by following a healthy diet according to what we've just suggested amazing Sarah thank you so much I have so many more questions but we're definitely at time I'm going to try and do a a little playback and and correct me if I got uh this wrong my take away from like discussing the complexities of what's going is in a sense it's quite simple that today you're saying the latest fence says really focus on this LDL number like you don't want that to be high if it is high it's a problem it's going to lead to like big increase in risks around um heart disease you saying HDL you don't feel quite as strongly about it as people have probably done even five or 10 years ago so focus on that LDL there is this apob measure so some people have seen that from their doctors and I think that's increasingly happening in in the states that's an even better measure but they're sort of saying the same sort of thing don't worry about the cholesterol in your diet that's got nothing to do with this actually your cholesterol is being sort of is very much driven by processes that are going on inside your body so it's a marker of something that's bad going on and interestingly your liver is playing this important role which I'm not going to try and play back because I don't think I've understood it well enough be able to do that that's both like you know clearing it away but also making these fats these triglycerides and so a lot is like is your body working in the right way that there's this sort of parallel um mechanism that's going on when we eat food and eating fat is really important the right sort of fats can really lower um our cholesterol the wrong ones can make it worse one of the reasons why we do this test for everybody um who who becomes a Zoe member is to understand how your body is working actually with eating food um eating these fats because that's so important for understanding how to give you the right advice that this 25% increase in LDL um as a consequence of going through menopause um which is an enormous shift and you're saying before this suddenly women have much lower levels than men and like afterwards they end up above so you can see why there's such a profound change in your body and also I think why you know I'm thinking now about sort of friends and family it's sort of striking how often they seem to have this diagnosis around this time period which I guess is not not by chance then SAR yep right and then you said like what can you do and the good news here I think is beyond um statins which you said can be very effective there actually is an enormous amount that you can do through diet and lifestyle which I think is is always really exciting to hear that you're not just stuck with it and that the advice is basically exactly the opposite of the advice that my dad was given 40 years ago so rather than saying don't eat any fat you're actually saying that if you're eating the right healthy fats you can actually reduce your cholesterol and so what that does mean is yes you know my dad was told to eat less red meat so that's true but he should have been eating more healthy fats as a result salt instead he moved to you know eating more bread and potatoes and things like this and SAR is like rolling her eyes because like well that's this terrible advice because your body has this ability to take these carbohydrates on and if you're eating too much of them that liver you talked about again is like turning it into fats and then you can end up actually having this high LDL as a result so don't feel you have to move to a lowfat diet do feel that you really need to change what you're eating also do really think about your carbohydrates though so actually eating these sort of poor quality highly refined food or Ultra processed food could be really bad for your fat however eating things that were high in fiber and whole grains could be really good um and I think final thing that you said is like if it says like lowfat food on the label it's almost certainly something to avoid yes I'm always cautious saying almost certainly but yes I think that's fair to say I believe we did a podcast on Ultra processed food and I just remember this thing about like almost any food that has like a printed Health claim on it you know like low fat or added protein or any of these things you should be very cautious about so that has stuck in my head I I think almost is the quite is the right word I mean you can take Greek yogurt and you can have some very good lowfat Greek yogurt that hasn't been you know fiddled with with all of these other ingredients Sarah thank you so much for walking us so clearly through a very complex topic I feel I understand it much better than I did at the beginning of the podcast and um I'm sure lots of listeners will as well thank you great pleasure thank you I loved having Sarah on the podcast today and I hope you learned something new from her now if you listen to this show regularly you already believe that changing how you eat can transform your health but you can only do so much with general advice from a weekly podcast if you want to feel much better now and hopefully live many more healthy years you need something more and that's why more than a 100,000 members trust Zoe each day to help them make the smartest food choices combining our world leading science with your Zoe test results Zoe is your daily companion to Better Health for life so how does it work Zoe membership starts with at home testing to understand your unique body then Zoe's app is your health coach using weekly check-ins and daily guidance to help you shift your food choices to steadily improve your health I rely on Zoe's advice every day and truly it has transformed how I feel will you give Zoe a try the first step is easy just take our free quiz to find out what Zoe membership could do for you just go to zoe.com podcast where as a podcast listener you'll also get 10% off as always I'm your host Jonathan wolf so Zoe science and nutrition is produced by Julie Panero Sam Durham and Richard Willen the Zoe science and nutrition podcast is not medical advice and if you have any medical concerns please consult your doctor see you next time [Music]