ZOE Science & Nutrition - Recap: What Prof. Tim Spector got wrong about Mushrooms and UPFs

Episode Date: July 30, 2024

While researching for his bestselling book, Food for Life, Tim dug deep into the new science around UPFs. We used to think they were unhealthy because of their high salt, fat and sugar levels. But there’s much more to the story.  Tim helps us navigate our UPF-filled grocery stores to eat healthier, and explains what he got wrong about a food group he'd previously overlooked... the humble mushroom. Learn how your body responds to food with ZOE 👉 start here 📚 Books from our ZOE Scientists: 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, two foods Professor Tim Spector says he was wrong about. Mushrooms and ultra-processed foods, or UPFs as they're often known. While researching his best-selling book, Food for Life, Tim dug deep into the new science around UPFs. We used to think they were unhealthy because of their high salt, fat, and sugar levels. But as it turned out, there's much more to the story.

In this clip, Tim helps us navigate our UPF-filled grocery stores to eat healthier. First up, though, the incredible health benefits of a food Tim previously overlooked, the humble mushroom. Yeah, I discovered lots about mushrooms, which I didn't know. I had no clue about i mean i used to you know enjoy the odd mushroom in a risotto or with a sunday fry up maybe but i didn't realize quite how many thousands and thousands of species there are and the fact that they're closer to animals than they are to plants as well so they're not actually members of the plant kingdom that's crazy and about a third of our the earth we're standing on is is made up of fungi and their their mycelium their network and a incredible how they can

produce these mushrooms that suddenly appear after a bit of rain and grow massively and then disappear again for another year it's incredible and it turns out they are potentially a real lifesaver for the planet, if we can harness them right, because they have an amazing amount of nutrients in them and are very high in protein levels as well. So it doesn't regard which species they are. And they have this meat-like quality to them that humans can recognize, the so-called umami flavor. So they're often used to disguise dishes between Italian sauces that, you know, they couldn't quite afford the meat, so they just put in mushrooms. And it's well known for centuries how you can do that.

And it turns out that not only is they high in all these nutrients, if you leave them in the sun, they actually, like humans, produce vitamin D. So rather than taking highly controversial supplements. This is after you've cut them and put them in a basket or while they're still connected to the rest of the fungus? Well, I've seen data showing both. So they can actually still produce it because many plants do actually stay alive once you cut them from the rest of the family, if you like. They will continue to still be alive. So we don't totally understand this, but they've now done commercially. So you can buy especially vitamin D enhanced ones, but

many mushrooms contain natural amounts of vitamin D. And I think we're going to see more and more of that as if our other sources might be drying up if we're having too much ultra-processed food. So that's interesting. They like to absorb the sun like we do and convert in their skins, in a way, precursors into this vitamin D, which they obviously use themselves. And vitamin D is very good for our immune system. But we know that my particular views are that vitamin D supplementation has not really succeeded in preventing any disease at all. So natural forms of vitamin D are really important. The last topic where I think you said you really changed your mind, and that is ultra processed food.

And maybe Tim, you should just start by explaining what ultra processed food is, and then explain how you've really changed your views about it. So the language around processed foods is complicated because most food we eat is processed to some extent. So even something like butter or milk can be considered processed because it's not just eating the raw plant or just cutting that bit of meat from the animal and eating it. But what we mean by ultra-processed is when the food itself no longer resembles the original ingredients, so that you are using extracts of plants or meats that no longer are the same as those original members, and you're putting them together in a factory in a way that you lose all the structure of those original foods, and you're just taking bits of them from a sort of chemistry set. They tend to have at least 10 ingredients, and to make them stick together, they've often

got these glues or gums or thickeners to make them seem like real foods again. So they're like reconstituting these foods. And this is unfortunately what constitutes 50% of our diet in the UK and 60% of our diet in the US. Which is an enormous number, right? So you're saying, you know, half to well over half of everything you eat is this sort of rebuilt food instead of something which bears any real resemblance to the diet that we clearly ate until

100 years ago. Absolutely right. And not every country does this. So there are countries in Europe and Mediterranean, like Portugal, that only have 10% of their food in that way. So it's definitely something that affects particular countries that maybe lack to food culture, but also have very strong business links and lobbying links of the food industry to point us in this direction. And the fact that we went for new, modern, scientific foods that may be easier to cook with and cut out a lot of those old time-wasting methods. But at what cost? And I think when I first started writing this book six years ago, the emphasis was all about, they have high in sugar, they're high in fats, they're high in salt. And that basically, if you reduce those three things, you can make them healthier. And that's still the main establishment government approach to ultra-processed food and one that the food industry is quite happy with because they can keep substituting different chemicals to reduce

the sugar by artificial sweeteners. They can reduce fat levels by increasing carbohydrates and other sugars and sugar alcohols, etc. And they can reduce the salt by, again, tampering with the structure of the food and using different preservatives. So all of it you can get round. But I think what I found was that there was some new research showing that ultra-processed food works not through the bad effects of those chemicals, those three macronutrients, if you like. But actually, it's the whole process. It's these extra chemicals that act in two ways to really harm us. First is our gut microbes through the chemicals like emulsifiers and thickeners and artificial sweeteners that in most people, and this might be personalized as well, our gut

microbes react to and produce chemicals that make us sicker than if we weren't eating them and might make us more hungry, might send signals to the brain to overeat and put on weight and generally mess up our gut microbiome. Just to make sure you know, make sure that we're all following. You're saying now you feel these chemicals in this ultra processed food, which is sort of directly triggering actions in these trillions of bacteria, which are then creating their own chemicals that really affect our health and our brain and things like that. Is that what you're saying, Tim? Yes. So it's not a direct effect. As you said, it's through our gut microbes, which I think we need to think of as like these pharmacies where they're producing chemicals for us instead of our body. And sometimes they produce the same chemicals that our body produces, but through an alternate

pathway and something that can, we're just learning more and more about all the things they produce. So this is a very new science, but it's showing us how things that we thought were completely inert, like artificial sweeteners, like carrageenins, which are like thickeners, or other lesser-than-emulsifiers, sucralose, they can't harm you because we've done the studies to show that. It doesn't cause cancer or anything but it does mess with your body and it does that we think through the gut microbes but the other convincing bit of evidence for me was this study from the NIH Kevin Hall's group where

compared in a very strict environment in a lab they gave gave, for a couple of weeks, people two different diets matched for calories completely, one a whole food diet made from real food, and the other, a copy of it made from ultra processed food. And they were both equally satisfying for the participants. But the group that had the ultra processed equivalent, kept saying they were hungrier and they went back to eat more and more every day. So they were overeating by about 200 calories a day. So there's something else in that food that's nothing to do with the calories, nothing to do with the salt, the sugar, everything else, because they were matched. That is telling the brain, eat more. And we don't know if that's direct or through the gut microbes. But once you really absorb that information, you think, gosh, if I'm having this every day of my life in some form,

this is perhaps why we're in such a mess in countries that have high ultra-processed food percentages in their diet, like the US, like the UK, like Canada, Australia, and Germany in Europe. That's why we've got part of this problem, because we've just seen it as a reductionist idea. Oh, we've only got to change the salt for potassium. We've only got to switch the fats for proteins and a bit of carbs. We've only got to take the sweetness away and add other chemicals. That changes nothing. And so I've really become much more anti-ultra processed food. And that's a big shift, isn't it? That you're saying, you know, I remember when we first talked that you were particularly concerned there was no

fiber in it. So it wasn't sort of positively feeding the bacteria. And now you're talking about it almost as if we were taking a drug, right? It sounds like almost like you're describing what would be happening if I was taking a medical drug that I don't need. And we all know that all these different, you know, many drugs have side effects, right? They say on the label, you know, may cause obesity or may cause nausea. You're really describing this as if these are sort of like medication, but we are not being prescribed it by the doctor, right? We're just buying it at the corner store and eating it because it tastes delicious. Yeah. And it's been designed by really brainy people, brilliant food scientists who have spent 30 years now trying to create this

perfect mix of chemicals that satisfies your taste buds and makes you want to eat more of it. And that's what they're paid to do. And they do it brilliantly. And they're doing it ever and ever cheaper. So using cheaper and cheaper products, more synthetic products to do that with really no restraints at all. Brilliant. Tim, thank you so much for spending the time with us. My pleasure. Thank you for listening to today's recap episode. I want to take 30 seconds to talk about something that's not talked about enough. Menopause.

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