The truth about organic food - according to science

0:00Welcome to ZOE Science & Nutrition, where world leading scientists explain how their research can improve your health.

0:15Today, we're talking about organic foods. Organic foods. Hang on, what does that even mean? And how do I know if something's organic? Oh, of course, because organic foods tell you so in massive letters on the packaging, and they cost way more. But as to what makes a food organic, whether eating organic is better for your health, or if the benefits are actually worth the expense, I honestly have no idea. And I don't think I'm the only one.

0:49Luckily, Professor Tim Spector is here today with answers. Tim is one of the world's top 100 most cited scientists, my scientific co-founder here at ZOE, and the author of the bestselling book, Food for Life, The New Science of Eating Well. Stick around until the end and you'll find the answer to our most asked question. Does Tim eat organic or not?

1:13Tim, thank you for joining me today. Fantastic once again. And I think this is going to be fun because we have never talked about organic food before and I'm actually not sure that you've really talked very much about it publicly at all. First time for me as well. So I'm excited and I'd like to start as always with our quick fire round of questions. Are you ready, Tim? Go for it. And we're going to be really strict today. Yes, no, or maybe. All right. Are there more nutrients in organic food? Yes. Can pesticides in non-organic food affect our health? Yes. Okay. Not sounding too good for the non-organic food so far.

1:53is there one food that you would definitely buy organic? Yes. If you're on a budget, is it crucial you eat organic food? No. And then I'm going to let you have a whole sentence, Tim. What is the one myth about organic food you'd love to dispel? That you can't trust it at all, I think is the common one, that you can't trust the labels, therefore don't bother. Got it. So it's all a lie, so you might as well just give up and just buy whatever. Ten years ago, I was very skeptical about organic food. I didn't really bother. I just saw it as being expensive. I just thought it was marketing hype, getting us to spend more money on things.

2:35So Tim, can we just start at the beginning and explain what does it mean for something to be organic? The key things about organic food are that it doesn't contain antibiotics. Antibiotics are not given in that food chain, not given to the animals. it doesn't contain any pesticides or herbicides or actual chemical additives of any kind and also the third thing is it doesn't include any artificial fertilizers so and tim what's the difference between a pesticide and a herbicide a pesticide is also known as an insecticide so it kills actually the living bugs beetles and other things that are eating the plants and a herbicide like Roundup is something you spray in your garden that kills weeds.

3:23So it's actually killing other sorts of plants rather than the first one killing sort of animals. It's killing plants and it's also used in organic food production to actually dry out the crops just before you harvest them as a sort of extra way of making the harvest easier. So generally we don't refer to herbicides much. We group them together with pesticides. So often if people are talking about, they're including herbicides and this chemical, which many people have in their garden called Roundup. They're the general rules. And so when you buy something organic, it doesn't guarantee that it's totally free of all these things.

4:02It just means the levels will be very much lower. And so just to make sure that I've sort of got that, this organic sort of has these two elements. One is about the way in which the food is being grown. And I sort of think about this as somehow just being less destructive to nature in that environment, right? Like not killing all the bees and everything else. And there's almost a second part, which is how is it healthier for me to consume it because it's got less pesticides and these sorts of things that are on the food. And so is that right, Tim? It's sort of like the combination of both of these as we think about organic?

4:36Yes, there's an environmental impact of these products. And we know that, for example, extensive use of fertilizers in fields runs off into our rivers and is actually causing major problems. Other chemicals also leach into killing other animals. And some countries use many more aggressive insecticides, for example, pesticides than others. So there's a whole group called organophosphates, which include the family of nerve agents and things like this, like Novichok, that some countries like Sweden have completely banned but are very common in the US and used at low levels in the EU but still allowed.

5:24And obviously around the world, there's very different rules. If you're getting food from Asia or India, you don't really know what's been used in those countries. So I'm listening to this and thinking I probably don't want nerve agents in my salad. But tell me, Tim, how worried should I be about pesticides in the foods that I eat? So most of these pesticides are checked to be safe in humans by studying mice and rats and seeing if it gives them cancer or what happens to their liver or other organs. They generally pass those tests, but they've never looked at other aspects, more subtle aspects of what happens to them.

6:05So these studies where rats are given organophosphates and you can see changes in their gut microbes means that they produce chemicals. And we've talked before about the gut microbiome as little chemical factories. And depending on how they're triggered, they'll produce different chemicals, vitamins in response to that. So these produce kind of weird chemicals when they're given organophosphates to eat. They respond differently, cause abnormalities, and can switch, in the rat at least, some of the sex hormones. So the phytoestrogens that occur naturally. So there's cause for concern based on rat and mouse studies, but I never believe them on their own.

6:51It's only in mice, only in rats. You can actually produce any result if you really want to, just by doing 20 experiments and picking the one that worked. No one generally publishes the other 19. So big human studies are the ones to go for. And then you've got, as usual, this whole range of epidemiology. So from the observational study that would just take a group of people that you follow for like 10 years and ask them based on their starting diets, you know, did you ever eat organic, yes or no? And often, because we weren't thinking about it 10, 20 years ago, the data is quite crude. So there's one study from Belgium that followed 58 ,000 Belgians and found that people who ate non-organic food ended up putting on more weight than people who ate organic food.

7:37Now that could be totally a health bias, right? I was going to say, this is one of the things we talk about all the time, right? Which is that people don't, they're not like rats. You can't make them do what you want them to do. So people have this whole bundle of their behaviors. So presumably people who eat organic food tend to also be like they smoke less and they are more careful about what else they eat and they probably are healthier. And so this stuff is very hard to untangle, right, in the studies you're describing where they're just observational. They observe it, but they do try and adjust in their models for the fact these healthy effects that you're describing.

8:13So they would adjust for smoking, adjust for exercise, adjust for education level, et cetera, et cetera. showing, they're still fine. But it was a one-off and no other studies really shown differences in weight. Then there was another study in the UK of 680 ,000 people. Again, a rather crude study because very large numbers and that has a yes, no, do you eat organic foods or not. But they did have good data on cancers and they didn't find any big effect on cancers in that study, but they did show an increase in one cancer called non-Hodgkin's lymphoma, which is a cancer of the blood, not that common, but they had increased rates.

8:52Then there was the Nutrisonte study, which has actually much more detailed information because it's really been designed for studying nutrition, and they've done similar studies on ultra-processed foods, and they've followed about 58 ,000 people, I think it is, for a period, I think it's about nine years. And they found an increased risk of most cancers by about 25%, including non-Hodgkin's lymphoma in the people that weren't taking organic food. And the organic food group were protected by about 25%. So that's a huge difference, right? 25 % lower risk of cancer. So how do you... So some of that could still be this fact you haven't adjusted for these healthy behaviors, but it's big enough to think there might still be something real in there.

9:44And again, this other, interesting, finally, this non-Hodgkin's lymphoma comes up again. And also there was interesting things in breast cancer went up after the menopause. And so certainly, again, just in rapturing up our slight worry about this. Obviously, that's just organic versus non-organic. If you took the people taking glyphosate, this is exposed to glyphosate, Roundup, which is what… Can you explain what that is? Roundup is this herbicide that is in most weed killers. And you looked at people with high exposures because they're doing parks or sports fields or spraying crops, for example.

10:32The epidemiology studies, they overall suggest there is a slight increase in cancers, and again, particularly non-Hodgkin's lymphoma. So there is some evidence that cancers are increased through long-term exposure to these chemicals. It's far from proven, but there is this strong link with non-Hodgkin's lymphoma, which seems to be more consistent than the other data. So cause for concern that way, there's also, there was a meta-analysis of about 20 small studies looking at infertility and problems during pregnancy. Again, suggesting a slight effect, but the studies were not well performed. And so low quality.

11:19So our sort of clarity on saying, yes, it definitely does that is not quite there. and there was also several studies looking at attention deficit in younger children showing there was a relationship there again poor quality studies but enough to be concerned that we should be sorting this out in a way that we you know no one is really addressing and the final study actually comes from our own twins where we were the only ones to look at the effect of organic food on the gut microbiome. It was an observational study. We took 60, I think, four pairs of our twins, working with some environmental epidemiologists.

12:08Robin Minaj was leading the study and looked at several hundred different residues, insecticides and herbicides and found that nearly everybody had some organophosphates type residues in their blood and urine. So just to make sure that I've got that, this is where I'm happily eating my pears and my apples and my leeks and whatever. I'm not out in the garden spraying this on my hands. This is from the food I'm eating. and you're saying that I went into your hospital lab along with 10 ,000 other twins and you took my blood and you could actually find bits of this, remnants of this pesticide in my blood?

12:57Is that right? Yes, I think it was over 90 % or something. So almost everybody had some. Yeah. So in your blood and urine, nearly everyone's got these insecticides and about 50 % of people had detectable levels of these herbicides, the glyphosate, the Roundup. And we looked at the gut microbes to see if these chemicals were having an effect. Was there a difference between people with high exposures, high levels in their blood and urine versus low levels? And there was a clear correlation. And so people who were eating more fruits and vegetables had higher levels of these chemicals. and they also had different changes in their gut microbes.

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14:45So people listening to this could be like, oh, so that's great. I'm going to give up my fruit and vegetables and I'm going to go back to my meat and saturated fat diet. And I'm going to avoid all these horrible risks, Tim, that you're talking about that I might get more cancer. Like, Is that the right takeaway from this? No. Okay. Well, if you go back, obviously people who eat lots of fruits and vegetables compared to people who don't or are on ultra-processed food diets of minimal fiber are likely to live 10 years longer and have half the risk of heart disease, diabetes, dementia, all the common chronic diseases.

15:32We've known that the fiber is really important, the plants are really important, the polyphenols, the defense chemicals in plants are really important for all bits of our body. Now, what we're talking about here is, I think, a possible 10 % increase in cancer risk, which, you know, in terms of a lifetime risk is a fairly small one for vast amount of people. And not every cancer. We're only talking about a few specific ones where there's evidence. And something like non-Hodgkin's lymphoma is a rare cancer most people haven't heard of. I don't know the exact rates, but it's going to be less than one in a few hundred people get it.

16:14You know, I haven't given up eating fruits and vegetables when I can't find organic, okay? To me, the advantages far outweigh any risks. So we're talking about a subtle difference here that probably only makes a difference if we're having them regularly and you know for decades but we'd still rather not have all of these pesticides in our food particularly at certain times in life where you know i don't think we talk much enough about it but there's critical times of pregnancy or feeding young children when you know there's so much happening to the body, the brain, and really don't want unwanted chemicals washing around that have all these effects we still don't really understand, you know, unless there's no way around it.

17:01Now, we've talked a lot about sort of the negative things that might come from pesticides and therefore organic food is almost just sort of saying, oh, well, at least it's got less of those bad things. But one of the things I've heard is, well, that organic food is supposed to have more nutrients in it and that's part of why the idea that the soil is alive with its own microbiome, all these things is better. Is there any truth in this Tim or is that just good marketing? There is some truth in this and there was a meta-analysis about eight years ago, about 300 tiny little studies that put them all together and it showed that on average the organic produce had more minerals in it.

17:46It had less cadmium, which is like a toxic mineral. And importantly, for me, it had around 30 to 40 % more polyphenols. 30 to 40%. Okay, so that's enormous. So that's like, you know, increasing your polyphenol intake by 30 or 40%. And that really is important. So just to remind people, that's the defense chemical that you find in plants that occurs naturally and is often in the tips of leaves or the bitter part or it's in the berries or these things naturally. So these are the things that naturally protect the plant against insects and the environment that it turns out the organic ones who are raised in our traditional ways have more of.

18:36And I think that's really fascinating because there's no one's exactly sure why. The hypothesis I like is the fact that if you surround these plants with insecticides and spray use, sort of taken away their, you don't need that defense, and you give them masses of fertilizer so they just grow. So all they really want to is grow. They're just like these giant sumo babies that are growing big and fat as fast as possible. And the environment is like super easy for them. And they have no defenses. And so, you know, if you grow too fast, you're likely to have a really bad immune system because the focus is on growth, not on prevention.

19:18I love this. So it's a bit like, so they are like the plant equivalent of homo sapiens living here in the 21st century in the developed world, are they? Where, you know, we can sit on the sofa all day, we don't need to do anything. And we now know that you really need to go to the gym. It's really important for your health. And you're saying it's a bit similar that the plants, the environment is not stressed enough. They are really couch potatoes. They're, you know, they're sitting there in the sun, everything's done for them. They don't have to bother. They to produce these defense chemicals like they used to.

19:51Because they're no longer fighting off these insects. And also, I guess they always get the right water and they get the right fertilizer. And that means, I guess, thinking back to some of the things you've talked about the microbiome, that they end up being different from the sort of foods we might have eaten until 100 years ago. So they have a lot less of these chemicals that our bodies would have just assumed they would get naturally with the food because way back in the past, no plants were being treated like this. So everything presumably had all of these defense cannibals because they were all in this fight for survival.

20:27Yeah, exactly. And it's the same thing if you look at how chickens have evolved, how we've grown these massive chickens in just a few weeks. They don't have anything like the nutrients and things of the old scrawny chickens that we used to eat. And I think this is all our food has been primed for growth and size and to look good. But when you look into the detail, you're getting actually less of the things that you need. So if you do buy the organic equivalent, you're going to be getting around 40 % more polyphenols, less toxins in there, slightly more minerals on average. And you are going to be getting a slightly better product.

21:13So the idea that it was a con, which was what I believe 10 years ago, is not really true. So I'm going to ask the question that our listeners have really wanted to ask from the beginning. It was like our number one question that we got from all the listeners beforehand, which is, Tim, do you eat organic food? I do, Jonathan. Yes. I know you might be surprised because when I'm out traveling, I don't insist on organic food. No, that's right. You generally seem quite relaxed about it and much more focused on whether you're eating plants. Yeah, exactly. Getting a diversity of plants is my number one priority.

21:49And I know it's hard to get diversity of plants and organic. And so that bar is just really too high, especially when you're traveling and you don't have those options you do at home. But at home, I would say 75 % of what I'm eating in terms of plants, fruits and vegetables, etc., is organic. And are you eating this organic food because you're worrying about cancer? Or are you eating this organic food because you're thinking you're getting more of those sort of good polyphenols you were talking about? I got really into this as I was, you know, six years ago, I started writing my book, Food for Life, which has a big section on this if anyone's interested.

22:28it wasn't just about cancer there was this you know these polyphenols it was the microbiome aspect of it i didn't really want lots of extra chemicals for decades going to my microbiome that on the one hand i was trying to build up in a good way so this was just seemed to be detrimental and you know i can now afford it so that's what i i've now done so i've changed my views on organic produce. But I think people shouldn't worry too much about things that they only do occasionally. I think what we're seeing here is this is something that you worry about for things that are in your diet regularly, and you're going to be having them regularly for years.

23:11So can we talk about that for a minute? Because I think you're in a nice position where your children have grown up and you're affluent enough to be able to do this with a lot of pressure. organic food is really expensive. How should people think about those trade-offs? And I'd love to talk about maybe are there particular foods where these levels of the pesticides and everything are really high and you should be really worried versus others. What are the foods where the pesticides are likely to be worst? Breakfast cereals that contain oats. Okay. That's incredibly surprising. I thought you were going to give me a fruit.

23:49Tell me about So oats, because they're often raised in damp countries, they are sprayed just before they're harvested to dry them out. Okay. And so this gives them massive amounts. And because they're wet, they absorb all that glyphosate. And so their levels are five to ten times more than many other grains. so that is something that is not not particularly a health food that i think uh people should go out of their way if they do love oats and i know you used to be a big oat eater although you're not anymore um you know and you can afford it either switch something else or go jump particularly if you're trying to give your kids something which you think is healthy i think that you could be giving them high levels of particularly this herbicide glyphosate.

24:43Rice is another one that came up interestingly in some surveys as being quite high in pesticides. And we do know that if you get certain areas of India and Pakistan do a problem with runoff of arsenic into rice paddy fields. So, you know, if you're getting cheap rice from certain places, you may be ingesting a lot of chemicals. And in general, fruits and vegetables that contain a lot of water will tend to absorb these chemicals more than others, and where they particularly attract insects as well. So cucumbers, pears, nectarines, these tend to have quite high concentrations. and everyone loves strawberries.

25:30I love strawberries, but in tests in the US and the UK, they commonly get tested as being above the safety levels. So we have these standard safety levels. And this again for these herbicides you're talking about? This is pesticides and herbicides. So these are the insecticides and the organophosphates and the glyphosates, really high levels. That's the sort of thing you should be wary of. If you have strawberries just once a year, it's probably not worth worrying about it. But if this is like part of your regular thing, just see if you can get organic strawberries. Or presumably swap to a different fruit that has lower levels.

26:12And other berries, I didn't used to, but I now try and get organic blueberries if I can. You can often get them frozen, interestingly, and they're not very expensive. if you buy the frozen organic berries and you stick them in the freezer. I was just thinking about this this morning. I get a lot of organic tinned food and a lot of organic frozen food because after podcasts that we've done in the past where I've discovered that actually like frozen vegetables and tinned vegetables are good, we now cook a lot of that at home. And what's interesting is that the price of still organic tinned beans is still incredibly cheap.

26:57So is that one of the areas that, again, you've picked up on three really good tips for people is, yeah, organic frozen food is really good. They don't have the same costs because it probably costs more to transport organic food because it does go off quicker. So you've got to be much faster. You can't just leave it around in warehouses for as long as possible. You don't tend to store them in those chemical bags and things. so that's a good tip about frozen foods canned foods i think beans do come up in some surveys as being high in pesticides so buying paying you know 10p extra or whatever for an organic bean can uh is is good value compared to the fresh one it's all a bit scary you're talking about like these pesticides and herbicides what can i what can i do if i've if i've got this can i you know can i wash this you know i was always brought up by my mother interestingly like i should wash the fruit washing helps but it doesn't get it down to organic levels but it doesn't get it down anywhere near to organic levels so you remove a little bit of it and you can peel them if you can't get an organic one you know probably peeling it gets rid of perhaps half but you still a lot of it might go beyond the skin so another little trick is if you're washing stuff add some sodium bicarbonate, baking soda, that is very good at removing...