ZOE Science & Nutrition - Recap: Why you should be wary of ‘low fat’ foods | Sarah Berry

Episode Date: September 30, 2025

If you’re a regular listener of this podcast, you’ll know that our cholesterol level is closely linked to heart health. With that in mind, it’s easy to be drawn to foods labelled as ‘low fat��, ‘reduced fat’ or ‘fat free’ - all of which promise to keep our cholesterol low and heart strong.  However, is it really that simple? I’m joined by Professor Sarah Berry to break down the difference between good and bad cholesterol, bust some myths about low-fat foods, and explain how we can make smarter food choices that support our heart. 🥑 Make smarter food choices. Become a member a zoe.com - 10% off with code PODCAST 🌱 Try our new plant based wholefood supplement - Daily30+ *Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system 📚 Books from our ZOE Scientists: The Food For Life Cookbook by Prof. Tim Spector Food For Life by Prof. Tim Spector Every Body Should Know This by Dr Federica Amati Free resources from ZOE: Live Healthier: Top 10 Tips From ZOE Science & Nutrition  Gut Guide - for a healthier microbiome in weeks Have feedback or a topic you'd like us to cover? Let us know here Listen to the full episode here

Hello and welcome to Zoe Recap, where each week we find the best bits from one of our podcast episodes to help you improve your health. Today we're talking about cholesterol. If you're a regular listener of this podcast, you'll know that our cholesterol level is closely linked to heart health. With that in mind, it's easy to be drawn to foods labelled as low fat, reduce fat, or fat-free, all of which seem to promise to keep our cholesterol low and our heart strong. However, is it really that simple? I'm joined by Professor Sarah Berry to break down the difference between good and bad cholesterol, bust myths about low-fat foods, and explain how we can make smarter food choices that support our heart. 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 make many different hormones. We need it 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 body.

Every single cell has this. Yes, has cholesterol. So without cholesterol, we would be in a little bit of trouble. And so if I understand, in fact, total, like we have to have it, we wouldn't live without it. Yeah. And that's why our body makes it. that, 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 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. 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 is 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 as 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 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 really healthy. But you just said in 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 cholesterol? So 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 blam and irritating. So let's 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 clestals, the cholesterol that's circulating in these good particles.

And the reason we want to do that, very simply put, is because the cholesterol that's packaged in LDL is the cholesterol that is circulating in our blood and delivered to our peripheral tissues. It's delivered to, you know, along our arteries where it can be, actually taken up into the arterial wall. The LDL particles have a particular label on them, which is called the apolliproproteen B label. So it's got like this address label saying that the receptors on the lining of our blood vessels recognize that enables it to cross over into the lining of our blood vessels because of this address label as a way of describing it

called apollipotene B. It's then taken up by the lining of the blood vessels. Over time, this causes this atherosclerosis, so this furring, which causes the narrowing of the blood vessels. And over time, you can get plaque formation. These can become unstable. These can then burst. And that's when you get a blockage, which causes a heart attack. What about foods that say low fat on the label? Because, again, this is one of the big things that, you know, lots of people, even today I'll be sort of given that advice as a way to try and navigate to,

like a better diet for their cholesterol? So I'm always cautious of any label that says low, no or reduced. Because 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 table.

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 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? Yeah, I mean, it depends on the type of food, but often, yes, 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 grain 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 just to make sure that I'm picked up on 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,

turn, 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, oh, there's too much of this and I'm going to start creating fats 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 if you've heard of that. Go on, Sarah. Many people who you hang out with will have heard of

beta glucans. I'm going to be the voice of many of our listeners saying beta what? Okay, so beta glucan is a type of soluble fibes. You've got two different types of fiber. You've got soluble fiber in soluble fiber. Soluble fiber, such as beta 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 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 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. But we know the insoluble fibre, which is the fibre 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 heavily refined against

there. We also know that there's other dietary changes we can make as well as reducing our refined carburetes, as well as increasing our fat, healthy fat intake. And the other that's often talked about is adding sterles 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. And they act a little bit in the same way as the 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 two grams 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 stannle kind of shot drinks that you get. So you might have heard of like flora proactive, etc. And so to get the required amount, you do need to really be buying these kind of products. They're very expensive. And so for someone, that is really concerned about their cholesterol, I might often suggest they try these, but I would say as 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. It's moving then to medicine. We had many, many questions about statins. 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. So I'm often caveatting 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 statins. 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 cholesterol level is, as well as your overall cardiovascular disease risk is. I think the evidence for 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 a medical opinion, that look at your diet first. Can you increase your polyunsaturated fat intake? Can you increase your fibre intake?

Can you reduce 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 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 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 until 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 emphasising 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 us 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 one millimole, 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. I hope you found the information in this week's episode useful.

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