ZOE Science & Nutrition - Most replayed moment: Blood pressure: the silent risk you shouldn’t ignore | Prof Tim Spector

Episode Date: June 30, 2026

Today we’re talking about blood pressure. Most of us know that high blood pressure is bad — but surprisingly few of us understand what it actually means, how widely it affects the body, or how to keep it under control. The good news is that monitoring blood pressure is easier than ever, putting you in a strong position to spot problems early and take meaningful action. Professor Tim Spector joins me to explain what blood pressure is, why it matters so much, and share some top salt-based tips that can have a powerful impact on long-term health. 🌱 Try our science-backed and tasty wholefood supplement Daily 30+ Get our brand-new app and Gut Health Test designed by world-leading gut health and nutrition scientists to build healthy eating habits 👉 Join ZOE Follow ZOE on Instagram. 📚Books by our ZOE Scientists The Food For Life Cookbook Every Body Should Know This by Dr Federica Amati Food For Life by Prof. Tim Spector Ferment by Prof. Tim Spector Free resources from ZOE Eating for Better Brain Health: Your brain-gut blueprint How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health Live Healthier: Top 10 Tips From ZOE Science & Nutrition Gut Guide - For a Healthier Microbiome in Weeks  Better Breakfast Guide

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 blood pressure. Most of us know that high blood pressure is bad. But surprisingly few of us understand what it actually means, how widely it affects the body or how to keep it under control. The good news is that monitoring blood pressure is easier than ever, putting you in a strong position to spot problems early and take meaningful action. Professor Tim Specter joins me to explain what blood pressure is, why it matters so much, and share some top salt-based tips that can have a powerful impact on long-term health. I have absolutely no idea what high blood pressure actually is. So what is it?

It is basically a hardening of the arteries and thickening of the arteries so that they're not as flexible. And these are the arteries, the blood vessels that go all around your body, from your heart, pumping blood to every bit of your body, including your brain. And each time your heart beats, there's a change in how much pressure is put into the system. And essentially, it's there to absorb that shock. It's also there to have a system. So if you're exercising or you need to run away quickly, your blood pressure can go up in short bursts, and that's normal, and it comes back again quickly. So you want a flexible mobile system. And what happens when you have high blood pressure, which is also known as hypertension, is that it stays up. It doesn't just come up and go down.

Your resting level is higher. So you've got more resistance to the whole system. It's like your pipes are firing up a bit. They're just not as flexible and bendy. And this puts a strain on the rest of your body. So it has to sort of work harder to do things. That's a lot. That's a very simple way of thinking about it. And where we draw the line about it being normal or abnormal is a bit flexible itself. So it could be that if we wanted to have the perfect blood pressure of, say, indigenous tribes in Africa, then we would put our thresholds even lower and maybe two-thirds of us would be counting as having high blood pressure in the West.

And it's considered a metabolic problem as well. So metabolic syndrome, which I think we've talked about in the past, is a combination of clusters of things that we get in the West where you might get type 2 diabetes, you might get obesity, get high cholesterol. And a part of that, as well as heart disease, is high blood pressure. And they seem to have similar causes and relationships. And they all lead on to one to the other. So if you've got one, you're more likely to get the others. Yes, if you have type 2 diabetes, are more likely to have high blood pressure. but it also works the other way around as well.

But if you got this defect in your blood vessels, that causes stress to all your cells in the way they're pumping out energy and using fuel in all the organs in your body, makes you more like to have kidney disease, makes you more like to have brain disease in terms of dementia, and affects all bits of your body to some extent. So it's not just a sub-rength.

So it's not just a sudden yes or no, I'm going to get a stroke or not. It has a really harmful effect on many aspects of your body. It needs to be seen as a metabolic disease rather than as a purely one-off thing on its own. It's a sign that your body's not healthy. So it definitely sounds really serious. It also sounds like lots of people listening on this podcast, when they go and get themselves measured, we'll discover their blood pressure is higher than they thought it was,

higher than this sort of healthy range. If they then reduce their blood pressure, is it too late to fix any of the damage or if they reduce their blood pressure? Does that reduce the risk of all these diseases in the future, even if it's been high in the past? It's never too late to reduce your blood pressure. I think that's the only the case, apart from people maybe in their hundreds. For most of us, even if you've not known about it for 10 years, you'll still get enormous benefit from getting that blood pressure down to that 120 over 80 range, where you will start to see the benefits, and your metabolism and your body will improve,

the inflammation will improve, your risks will suddenly drop of many of these conditions. Some of the damage will be done, but you'll still be protecting your future life in a big way if you take action. So I think you have got to be very positive about this and not think about the past, think about the future in your future years. And especially, you know, I've seen my mother have a stroke.

She had poorly controlled blood pressure, and we all know people like that. And it's such a preventable condition that we really all need to be taking much more care of our blood pressure. So if you don't mind my asking, when you talk about that example with your mother, are you saying that you feel that if she'd managed to control her blood pressure, better, she might not have had that stroke? I think that's correct, yes. The data show that if your blood pressure is well controlled, as opposed to poorly controlled, it can halve your risk of having a stroke.

You can never eliminate the chance completely because sometimes people have stroke without having high blood pressure, but you can dramatically improve the odds. So, Tim, I would love to switch now to that actionable advice. Is there anything that people can do in terms of their lifestyle? Absolutely, yes. So lifestyle changes, as we've discussed many times, are important. So if you're too sedentary, that's going to put your blood pressure up. So try and do some exercise. Sedentary is like doctor speak for sitting on the couch and watching TV. Sitting on your bum all the time. Yeah, exactly. Modern lifestyle, working at home, very bad for you. Get out there, do some walking, do some exercise.

That's good for blood pressure. Sleeping well is also related to blood pressure. So, sort out your sleep as much as you can. That's not just one of these sort of hand-wavy things. Your sleep really has an impact on your blood pressure? Yes, it does. And again, we see this repeated because blood pressure is part of this metabolic group of conditions that all seem to have similar causes. A poor night's sleep or doing lots of shift work will actually raise your blood pressure.

So particularly if you are doing night work, shift work, you are more prone to these problems. So it is a risk factor. Generally, we did sort of laugh off stress, but if you've got chronic stress in your life, then that is associated with blood pressure in many studies. And try and find ways of reducing that through something you enjoy, whether it's sport or it can be something like yoga, it can be like meditation. It can be through having sauna. There have been some small studies showing that people who have regular,

saunas do have lower blood pressures. So anything that, and it sort of makes sense because you're expanding and you're stretching your blood vessels when you're going for a sauna. They're trying to keep up and keep your temperature constant. So they're having a little workout. So this is like the gym for my blood vessels is just to sit in a sauna and sweat. Correct. Yes, exactly. I love that. It's definitely less painful than the ice baths. We know that that's not my thing. I know you prefer sauna to ice baths. But the same way, mindfulness and yoga, they do relax you and you will get some benefit from that as well. But I think the main thing we should focus on that everyone can do is to think what in their diet can they do to get their blood pressure down because every millimeter counts.

So can we talk a bit more? Can we start to dive into diet then? Maybe start with what might be causing the problem. What in my diet might be raising my blood pressure? These would be most likely be processed foods that have high salt content. We think that about 85% of the salt you get in the average American or British diet comes from pre-packaged, manufactured, highly processed foods. So almost all the salt does not come from when you pour salt onto your meal. Unless you live and work in a French restaurant, then it's only about 10% of your intake.

It varies a bit, but it's at most 20%. So at least 80% is coming from prepackaged foods that you're buying, whether they're in canned soups, whether they're in biscuits, they're in musli, they're in children's cereals, things that you don't expect to find so much salt. And is that more salt than we would have put? in our diet, you know, in the past when people would have just been cooking their own versions of these meals? Much more, yeah.

It's like three or four times more you were getting. And they're often doing it to disguise some of the other flavors. Salt is used to disguise a lot of the chemicals that they're putting into these foods. It's also there to provide this hyper-pallitability. This is a term we've talked about, make you overeat. So by adding a certain amount of salt to things, if you combine that with salt and fat in these foods, you will naturally overeat and therefore spend more money on that company's product than you would otherwise have done. So this is like a big part of what sort of big food is putting

into these meals, either to hide like the ingredients that you might taste and don't taste as nice, or just to make you have that thing where you just can't stop eating and it's sort of that sort of magic point where it's so delicious that you're just going to eat the whole pack. Correct. And it's obviously so vital to their product. They really haven't. worked out a way of doing without it. And so it's the number one thing that we should be avoiding. And it's the worst thing is it's in many, you know, children's products and things you don't even think are salty. I mean, don't normally think of cookies or biscuits as needing salt in them. And yet, there they are with the sugar, you've got the salt. It's often used to preserve them for even longer shelf lives as

well. So that's where most of the salt comes from. And I don't think there's any harm in telling everybody who's worried about their blood pressure to avoid those kinds of foods. Because even if it doesn't dramatically reduce your blood pressure, if you're not particularly salt sensitive, you get so much other benefits from not having those kinds of foods anyway. So I think everyone should be doing that. The second thing you can do is if you do find yourself adding a lot of table salt to your food, you're someone who likes that, you might want to switch to a different type of salt called potassium chloride. So this is sometimes labeled as low salt alternatives. So salt has the chemical formula sodium chloride and these low salts are potassium chloride and they're basically

mix the sodium chloride with potassium chloride to give you a similar taste, but much less of the sodium and more of the potassium. And when they've done clinical, randomised clinical trials of this, they show that if you switch this around and you're not having all the other sort of junk foods we talked about, you can reduce your blood pressure by about 3 to 4%. So more than just reducing salt on its own. So that's a pretty good tip.

The only problem is for many people, they have a rather metallic taste. And they don't like it. But this is what manufacturers should be doing. They should be putting much more potassium than sodium into these pre-packaged foods. That would really help make them less harmful for us. The other big thing is realizing that just by increasing your potassium level, you will be improving your blood pressure, be reducing it.

And the best way to improve your potassium level is to eat more varied plants. I'm not into superfoods. I don't think people should be eating tons of kiwi fruit necessarily, but that's a good example of one that is full of potassium. But fruits and vegetables in their natural form are fantastic sources of potassium that we should all be eating more of and less salty things. and just change that ratio. And the more you do that, the more you be able to improve your blood pressure naturally,

you know, even before you're going on to blood pressure medications. And they can also enhance blood pressure medication. So it's not either or. I think even if you're on a blood pressure medication, the more you can help it with diet, the less you need to go on to higher doses or a second one which could give you more side effects, et cetera, the better you'll be. So you feel like combining this with medication makes sense?

This isn't something where just popping the medication sort of solves the problem for everybody. Absolutely, yes. So I think they should be used together. I think we should be seeing diet as another arm of medication, not as a complete alternative, only if you don't believe in medication. Because for this particular condition, that the evidence is so clear that medication will save your life. and will stop you getting a stroke and heart attack.

So I don't want anyone to think that this is instead of. It's usually in addition to. It might mean that you can eventually, you might be able to get off your medications. If you're someone who started them when they're on a really poor junk food diet, your doctor didn't tell you that that reason was you were getting all these terrible blood pressure-inducing effects from the food, you've changed that, you've improved your life,

you've improved your gut microbes, they're secreting other chemicals, you might then be able to wean yourself off these drugs. That's possible. You've certainly heard stories of this from people who've written to me. So bear that in mind, but, you know, do that under medical supervision. Hosting this podcast means I get to quiz world-leading scientists every week about how to improve my health. But I'll be honest with you. For a long time, my snacking habit was completely out of sync with the science. I'd hit an energy slump, grab a snack bar, and usually inhale it in two bites while looking at my phone. I knew that the ingredients were a bunch of artificial additives and emulsifiers, but honestly, I was hungry and usually there was nothing else healthy to eat. It wasn't until our chief scientist, Sarah Berry, explained the physics of snack foods on this show that it finally clicked.

Highly processed bars are engineered to be eaten fast and release their sugar immediately, which in my case, caused a sharp spike and then crash in my blood sugar, leading a few minutes later to a collapse in my energy and a spike in my hunger. In my opinion, this is a cynical move by big food companies to make us eat more. I was furious, but Sarah said she thought we could solve this. She came back a year later with the Zoe gut health bar and had done something completely radical. She'd left the natural cell structures of the plants intact. The first time I tried a sample, I realize you physically cannot rush it. It tastes great, but because the bar preserves that natural food matrix, it's also wonderfully

dense and chewy. So it forces me to slow down and savour it. It delivers a huge diversity of over 12 plants. And because it breaks down slowly in your body, you avoid that sudden sugar spike and crash. Plus, both flavours are just delicious. My favourite is, of course, the 70% dark chocolate. I've got to admit, as a chocoholic, I did ask our gut health scientists to make sure we had that option. If you're ready to swap your additive-laden snack bar for something that's designed to be good for your gut health,

head over to zoey.com slash snackbar. That's zoe.com slash snack bar. Your gut will thank you.