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- [00:01]
A
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 diving into coffee. Most of us are greeted by its earthy aroma every single morning, its hot, bitter taste signaling that the day has officially begun. Coffee is so ingrained into our daily routine, we rarely pause to consider the effect it has on our health. So what is coffee? A health boosting elixir or just another guilty pleasure? I'm joined by Professor Tim Spector and coffee expert James Hoffman to explore one of the world's most popular drinks.
- [00:40]
B
Well, for many years we thought coffee was bad for us because short term it increases your heart rate, increases your blood pressure. For decades, people said this is a rather dangerous thing to be having. Don't do too much of it, you're going to have a heart attack. Then they started doing some proper studies and have shown that you actually, based on over 25 studies, you can now see a reduction of about 25% in your risk of a heart attack or heart disease. So then you're saying, why would that be something that short term might be slightly stressing your system is actually long term good for you? And I think it's seeing as coffee as this hole, coffee is this fermented plant that has microbes acting on it, has hundreds if not thousands of chemicals produced from it, and it's probably a combination of all those things that gives it this health benefit, such as the fiber in it. And we used to think, not think of coffee as a fiber rich drink, but we now know that broadly you can get about 1.5 grams of fiber out of a cup, which means if you're having three cups a day, that's, you know, 4.5 to 5 grams of fiber, which, you know, it's a quarter of your daily fiber intake in the, in the, in the UK and the.
- [02:05]
A
US I always find extraordinary because I always somehow in my mind think about fiber as being like, like this roughage that you can't. Like bran. Exactly. Or like, you know, the stuff that my grandmother, you know, might stir into a glass of water. Yeah.
- [02:19]
B
And two cups of coffee is more than a banana in terms of fiber.
- [02:22]
A
But the point is it's a drink. So like, where's all that? I don't, you know, where's all the solid bits of fiber? And this is because of my understanding of fiber isn't quite right.
- [02:30]
B
Well, that's right. Well, fiber can be in drinks and can be small particles that are still going to have A similar effect when they reach the lower part of your intestine where all the gut microbes are. And there are soluble fibers and there are insoluble fibers and you know, they may be, some of them might be invisible. So I think that's the way it's.
- [02:47]
A
Actually dissolved into the drink. So there can be fiber in something you can't even see, which is, we.
- [02:51]
B
Always think about like, it's just like eating spinach or something, but actually it's not like that. And there are lots of different ways that we can get fiber into our body. And until recently we didn't appreciate this. And it's not in most sort of nutrition textbooks as, you know, health drink. But there's more fiber, you know, generally in coffee than an equivalent amount of orange juice, for example. So it's not sufficient. I'm not saying you can live just on coffee and have a good, and have a good diet. But given that, you know, in the west we're very fiber deprived, it's actually perhaps the thing that's just keeping us going on this very low fiber diet and making up, you know, perhaps a quarter of a third of our, our fiber amounts. So it's the fiber, but it's also these individual chemicals that we're still just getting to understand. And this range of polyphenols that are in the coffee bean, some of them are enhanced by the microbes as they ferment it and those are released and those have direct effects on our body. And some of them can reduce blood sugar and reduce stress and actually reduce blood pressure and things like this. So it's, it's a complex area, but I think we're suddenly putting it together from a drink that was demonized as being very harmful to us to something that actually could be beneficial. And the other interesting thing is we always thought it was about the caffeine. And the studies have now clearly shown that you get nearly as much benefit on the heart with decaffeinated coffee. And again, it comes back to this idea of how we see foods is we always think of this one thing coffee's all about caffeine and lemons is about vitamin C and we forget everything else, but all these other stuff going on in that food that can give us these huge benefits.
- [04:50]
C
I think it's the great frustration of coffee conversation is the substitution of coffee and caffeine. It's this incredibly well studied drug. We know a lot about caffeine, but it's not all that coffee is. But it ends up being all that we Talk about most of the time when people want to talk about coffee and health.
- [05:06]
A
Do we understand why coffee is full of not only caffeine but all of these other polyphenols? What's that? Most of us think about coffee as being either something ground that we buy from our grocery store, or maybe we think about it as like this like blackened thing that looks a bit like a bean, but we definitely don't think about it as a plant or anything else. What's the.
- [05:29]
C
The caffeine's easier to sort of understand the presence of. It's primarily produced by the coffee in the coffee fruit. So coffee beans grow in sort of a cherry. It's about the size of a small grape with two peanuts like seeds in the middle. So if you look at a coffee bean that's two flat size, they would typically face each other as a defense mechanism. The plant produces caffeine to act kind of as an insect repellent, for want of a better term, to discourage insect attacks on the fruit. That's really why it's there in the quantities that it is. Therefore, you tend to see species of coffee that are hardier and more robust. One of which is robuster, grows lower, more insects are present, twice the caffeine levels of something like caffea arabica, which grows higher up and obviously has less challenge. And so it needs less defense. But yeah, that's the primary reason caffeine exists. Caffeine is produced by other plants.
- [06:23]
B
Yeah, tea leaves as well. So I mean green things, I mean, not green, more the black tea ones for the same reasons.
- [06:29]
A
And polyphenols themselves are also what I understand defense chemicals is how I've heard you and others describe them. Tim.
- [06:35]
B
Yeah, this is again, it's an incredibly broad family. But in general, these are chemicals produced by plants to defend themselves not only against insects, but it might also be against high winds or could be cold, or it could be strong sunshine, or it could be to change the way predators, you know, the taste and things for predators. But generally it's a defense mechanism for plants that ends up having a side effect of being beneficial for our gut microbes. That's how nature has come as full circle.
- [07:14]
A
Imagine that I'm going into a coffee shop rather than making this at home. What is James's top tip for picking the best coffee in that situation?
- [07:24]
C
First and foremost, I'm going to be pro independent coffee shops. They have a different motivation. They're trying to Winnie, waver with the quality of the product, not with convenience and familiarity, which is how Chains tend to work, so it's worth the gamble to find a good independent coffee shop. They'll care more about the coffee, it'll be fresher, it'll probably be of higher quality, it'll probably be theoretically higher in things like polyphenols, which, that's a broad statement and I'm very nervous making it. But you would hope that would be the case. And so that would be the first thing. And then I think as long as coffee is well brewed, which again, independents these days tend to do well, whether it is a flat white or it is a filter coffee or it is a straight espresso, it's actually a matching kind of extraction of the raw material across all of those things. And so you should see the benefits kind of regardless of your preferred drink. But people or independent businesses are excited to talk to you about what you like and help you find something that you like. And it's always worth a conversation and finding your local sort of place. I think we don't have that feeling as much anymore of like your local coffee shop. And that's a shame. You know, that's the thing independents offer over chains too, is community space, experience. So, yeah, all those things is why I'm pro independent business.
- [08:37]
A
And one question that we were asked a lot from our listeners was what about people with high blood pressure? So, Tim, you've been talking about all the great health benefits of coffee, but you also mentioned, I think that historically people were told not to drink, drink coffee because it raised blood pressure. If you have high blood pressure, what's your advice?
- [08:57]
B
I think if your blood pressure is not under good control, then you have to be very careful with, with coffee and caffeine. But all the studies suggest that if you're just starting to drink coffee, it's only the first few weeks that your blood pressure will go up and then it stabilizes. So I wouldn't advise anyone to completely change their diet or anything they're doing if they don't have stable blood pressure, get it stable and then start to slowly introduce coffee into your diet. It's not, as far as I'm aware, a contraindication. If your blood pressure is well controlled. I monitor my blood pressure and coffee has no effect on that. And there's some evidence that long term it might actually reduce your blood pressure.
- [09:49]
A
Got it. So you're saying if someone's listening to this and they have high blood pressure, but it's under high control and they like coffee, you're not saying, don't worry about it, give up.
- [09:57]
B
And they were old studies, they're out of date. They showed that people who hadn't been exposed to coffee, if you give them large doses short term, your blood pressure can go up. So obviously if you have a problem short term, you don't want to have that problem. But if it's well controlled, then no real problem long term and long term. We know from all the epidemiology that for the average person they will get derived benefit in terms of their heart health. But the caveat, as always is everyone is an individual and all our responses are going to be different. We can't give advice that is going to apply to absolutely everybody. We're talking at this point averages.
- [10:43]
C
And there's always decaf.
- [10:45]
B
Yes. So there's always decaf. And I think the blood pressure story was mainly about the, the caffeine side of it. So as we've heard, decaffeinated coffee is safe. The chemical processes are now considered very sophisticated safe. There's plenty on the market. Find one that you like. No need to have caffeine. I think everyone's got to work out, you know, there are lots of factors that affect your caffeine metabolism. Work out what suits you, experiment, find out, you know. But for many people, it does get them going in the day and gives them a clarity of thought, you know, in their thought processes and other things that are important. And that's why I have coffee in the morning, but I don't have it at night.
- [11:31]
D
That's it for this week's recap. If you're hearing this, you're already on your way to making smarter food choices with world leading science speaking of making smarter food choices, Zoe membership helps you do just that with scientific solutions that let you listen to your gut. Listening to your gut starts with an at home test kit that helps you understand your body's responses to food and the good and bad microbes in your gut. Then Zoe's app helps you build life changing nutrition habits step by step. Become a Zoe member today and give your gut the love it deserves. The first step is easy. Go to Zoe.com and use the code podcast to get 10% off. As a Zoe member, you'll get a comprehensive at home test kit and personalized nutrition program. So go to Zoe.com and get 10% off with a code podcast.