Hi, I’m Rose Rimler, filling in for Wendy Zukerman this week, while she’s off riding brumbies in the outback. And this is Science Vs, the show that pits facts against newFangled food. Today we’re talking about processed food, asking– what is it doing to us?
To start, let me tell you a story about something that happened more than a century ago in Japan. For generations, most of the rice eaten in Japan was brown rice– but in the late 1800s, machines were invented that made it much easier to turn brown rice into white rice– by stripping off the outer parts of the rice.[1][2] And this turned white rice from something mostly eaten by wealthy people to something that people all over Japan were eating[3]..
And soon after…this weird disease that was once rare – exploded. It’s called beriberi. And it sounds awful. Your body can swell up, you can lose feeling in your hands and feet - even become paralyzed[4]. In fact, it can kill you[5]. A princess in Japan likely died from it.[6] And by the turn of the 20th century, it was estimated that beriberi caused 8% of deaths in Japan every year[7][8].
And it wasn’t for decades more that the culprit would be understood: It was the processing of the rice that killed people. Stripping off that outer layer also stripped off this really important B vitamin in the rice.[9] Beriberi was simply a vitamin deficiency.
These days, we can eat white rice without fear because we’ve figured out how to put that vitamin back in. But I wanted to start off today’s episode with that story because now, we do a LOT more to our food than we did back then….[10] We process the crap out of it. We do stuff like cram it into bars, mash it into funny shapes and pump it full of fake flavors …
Media clips:
So what you’re really getting are chemicals, additives - think things like preservatives, sweeteners, coloring, flavoring, trans fats, emulsifiers
Basically they can withstand a nuclear holocaust and they’re not good for us
I always say the whiter the bread, the sooner you’re dead
And we’re eating a ton of this stuff.
Media clip: New numbers on just how much processed food Americans eat. A new study finds ultraprocessed food makes up more than half of all the calories in the US diet. I know that sounds scary and I don’t even know why [laugh]
Yeah, in the US, just under 60% of the average person’s diet is ultraprocessed food[11]. Which sounds scary to me too — and I also don’t know why! So that’s what we’re going to dive into today. We’re asking: What's so bad about processed food?? And we’re gonna look at a few different potential problems with this stuff. Including …
1) The additives we’re pumping into this food —
2) The chemicals in the plastic packaging — could they be sneaking into the food and messing with us? Or —
3) is the problem waaaay simpler? Nowadays, a lot of our processed food seems like junk food– is the real issue the fact that it’s packed with fat, sugar, and salt?
Because when it comes to processed food there’s a lot of …
That sounds scary, and I don’t even know why
But then there’s science.
AHHHH
Science Vs Processed Food. Coming up after the break.
BREAK
Welcome back. Today on the show. Processed foods. Let’s dig in. So generally speaking, when nutrition nerds study this, they are actually interested in something called ULTRAprocessed food[12][13] – which is a term scientists came up with to distinguish this stuff from REGULAR processed food. That’s because most of our food is processed … any time we cook or blend something … we’re processing it. And ultra-processed food? It’s a little hard to define…
KH It’s kind of like the way people have often tried to define pornography, right? It’s hard to define but you know it when you see it sort of thing
RR laugh
This is Kevin Hall. He’s a researcher at the National Institutes of Health who studies food and our metabolism.[14] He said you can basically think of ultra-processed food like this —
KH A lot of the prepackaged, ready-to-eat, ready-to-heat foods that are sort of in the middle of the supermarket
So rather than cheese, we’re talking about cheese wiz, instead of plain yogurt, Gogurt. Industrially made bread, cookies, frozen meals, that kind of stuff.
And it turns out that people who eat a lot of this food — do tend to be sicker than people who eat less of it. One of the biggest studies that shows this comes from France.[15] Scientists there recruited over 100,000 people and asked them to report what they were eating– and kept an eye on their health over the years. And they found that every 10% more of this food they ate, the risk of certain diseases went up by about ten to fifteen percent. This was stuff like cancer[16], heart disease[17] , and diabetes.[18] And even death[19].
Other studies have found similar things– in Italy[20], Spain[21] the UK[22], and the US[23][24]. And the risk sticks around even after researchers adjust for stuff like education and income.
Kevin, our scientist, has been following this research. He thinks it’s interesting, but he figured there’s a simple explanation for what’s going on here. He points out that these ultra-processed foods tend to be higher in fat, salt, and sugar[25][26]... in other words…a lot of it is junk food. So Kevin thought it was wrong to blame the processing– it’s more about the nutrients. He suspected that if people ate fresh food with the same amount of fat and sugar, they’d see the same health problems.
So he came up with a clever way to try to single out the effects of the processing itself …
KH If there’s something bad about these foods, then I should be able to design a study where I match for the salt, the sugar, the fat, the fiber. And if it’s really about the nutrients then there shouldn’t really be any effect
So, Kevin recruited people for a study where they would eat either ultra-processed food or food made from scratch. The key thing was that he controlled every single meal so they had the same amount of all the major nutrients.[27] He did this by having them MOVE into the lab. For a MONTH. He told them…
KH You're basically gonna be staying in a hospital ward, and you’re gonna have your own room, and you’re gonna have your bed, and your bathroom, and your shower, and all that sort of stuff. But every day we're going to basically give you three meals and a snack box.
Everyone ate either an ultraprocessed or a home-cooked diet for two weeks — and then they swapped to the other diet. All the while, Kevin’s team is poking and prodding them …
KH We're basically gonna take a lot of blood from you [laugh] and we’re gonna measure how your body's responding when you're exposed to these basically two very different food environments
RR So what did they do all day besides eat and have blood drawn?
KH Well, it varies, right? So we actually have people who are authors and actually want some time to kind of write their manuscript and so they come in
RR oh like a writer's retreat
KH yeah
There were also a lot of college kids on their summer break.
So when they got the less processed meal, it might be something like a yogurt with fresh fruit and nuts. But an ultra-processed breakfast would be a store-bought muffin and Honey Nut Cheerios, for example.[28]. To you and me, these two meals seem pretty different, but to a nutrient guy like Kevin, their building blocks are the same: You had the same amount of fat and sugar in the yogurt with fruit and nuts compared to the Cheerios and muffin. He even got the fiber to match with fiber supplements. And everybody could eat as much as they wanted, and after mealtime, Kevin’s team looked at how much they ate. He also tracked their weight and a bunch of other stuff.
And he figured that if processed food is bad JUST because it’s full of fat and sugar, then he would see no difference between the two diets. But instead…. There was a difference.
KH Yeah, so i was wrong! [laugh] It turned out that people ate a little over 500 calories per day more on average during the ultraprocessed diet. This is a huge effect.
Yeah, so people gained about two pounds in the two weeks they were eating ultraprocessed foods, and they lost two pounds when they switched to the less processed meals. Kevin says one thing going on here - was that on the ultraprocessed diet, people tended to eat faster[29] – maybe because this food is softer and goes down easier.
The overall point here is that there was something different about this kind of food - compared to the home-cooked stuff. To Kevin, this suggests that the problem with ultraprocessed food - is bigger than the fact that a lot of it is junk food …
KH Y’know i think that there's something there. And it's probably not because of the salt, the sugar, the fat, and the fiber, it's probably some other factor
So Kevin’s study found that eating ultraprocessed food made people gain weight. His study can't tell us whether this would make people sick in the long term. But it’s tempting to think that the weight gain is the answer – because we know that being heavy can increase the risk of illnesses like heart disease[30]. And that might be part of it – but it’s not the whole story. Remember those big studies that follow people who eat lots of ultraprocessed food? Well, when the scientists adjust the results to take people’s weight into account, they still find a link to these diseases. In other words, when it comes to eating ultraprocessed food, where you land on the scale doesn’t matter that much – the risk is still there.[31][32][33][34][35][36][37].
So what is this “X factor” that makes this food bad for us beyond making us gain weight?
BEAT 2– FOOD ADDITIVES
Well, the next thing we’re going to dive into here is ADDITIVES. A big Pew survey in 2018 found that about half of Americans think additives in their everyday food are a risk to their health.[38] And it makes sense – because with a lot of ultraprocessed foods, when you flip over the package, you find some weird-sounding ingredients … Producer Meryl Horn and I went to the grocery store to see what’s in this stuff …
<<grocery store ambi>>
We learned a lot of new words….
MH Mixed toco…tocopheeerols … tocopherols?[39] Am I even saying that right?
RR Hexa metha - hexa meth - hexa metha phosphates
We looked at frozen meals, jarred sauces, and even meats…
MH I feel like you kind of know when you're eating a chicken nugget you're signing up for a gamble like, what actually is going into your mouth?
RR Yeast extract. Spices. Guar gum. Dried garlic, dried onion, cottonseed oil
There were also plenty of additives in food we may think of as healthy … for example, a lot of vegan foods are ultra-processed…In vegan yogurt….we found something called locust bean gum…
MH I don't even know what that is. Locust bean doesn’t sound like something I’d want to eat…
RR Yeah, it sounds like something that would crawl out of the ground every seven years.
MH Yeah
But just because Meryl and I don’t know what something is doesn’t necessarily mean it’s scary. So when we got back from the store, I looked up some of these additives. And you know how knowledge is power – most of them seemed pretty innocent[40] when I learned what they were. For example, mixed tocopherols are vitamin E – it’s an antioxidant that stops food from turning brown… and yeast extract is a flavoring that tickles our umami receptors…[41]!
But there are some additives that have raised eyebrows. And one man with eyebrows raised almost to the ceiling is Carlos Monteiro. He’s a professor of nutrition and public health at the University of Sao Paulo in Brazil[42].
RR Hi Carlos
CM Hello
Carlos has been studying ultraprocessed food for years … he actually coined the term in a 2009 paper[43][44]. And he says - new food additives are popping up faster than science can study them …
CM In the past, I mean, we had just a few additives — today you have thousands![45][46]
And well, here in the U.S. – the FDA vets a lot of of the additives that end up in food[47] …. but we know some bad stuff has snuck in in the past, so we can't always count on that[48][49].
And Carlos says there’s one group he’s particularly concerned about, that’s found in A LOT of food: emulsifiers.
Emulsifiers are used to mix and thicken food. They’re a super common type of additive[50][51]– They’re in all kinds of stuff – bottled salad dressings, store-bought cookies…and even ice cream.[52] Ice cream[53]!! And it looks like some of these additives could be doing something weird in our gut. Carlos spoke about it with Meryl.
CM The recent research is showing that when they arrive to our intestines they clean the walls in the intestine. They act as detergents.
MH Detergents? So that’s like soap?
CM Exactly, yeah.
Here’s what we think might be happening[54]. Basically, it all starts when some emulsifiers kill off some of our friendly gut bacteria, and that allows the less friendly kind to thrive. Evidence for this has been trickling in from mice and lab studies for a few years now[55]…[56][57]. And just last year we got research showing that this bacteria die-off can happen in real people who were fed an emulsifier in a controlled study.[58]. In these people, the not-so-friendly bacteria were free to gnaw at the mucus lining of their guts - which meant the bacteria might be able to wriggle into the gut lining and cause problems - like inflammation [59]…
CM So emulsifiers can disturb the ability of our walls in the intestine to absorb what they should absorb and what they should not absorb.
Now, this was a small study, and the participants got a pretty high dose of this stuff[60] – more than the average person would eat in a day[61][62]. But maybe if we eat lots of ultraprocessed food every day, we’d be slurping up a bunch of different emulsifiers, enough to cause problems in real life – like leaky, inflamed guts. The evidence was enough for a group of gastroenterologists to publish guidelines that say people with some digestive diseases - like Crohn’s and ulcerative colitis - should avoid foods with certain emulsifiers in them[63][64]. As for the rest of us? Well, there’s currently a big trial underway testing emulsifiers in people without these diseases – so, hopefully we’ll know more soon[65].
People are also pointing fingers at other additives – and while I’m finding that there isn’t a ton of research on most of them, I did want to just spend a little time on one other additive – because I found the research there pretty convincing. I’m talking about these preservatives called nitrates and nitrites. These are mostly used in lunchmeat,[66] sausages,[67] and bacon.[68] And they might actually cause cancer– because when we eat them they react with other molecules in our body to create carcinogens[69][70]. Just last year, those French scientists who have followed big groups of people who eat ultra-processed food - they put out a paper on this. It showed that people who ate more foods with added nitrates and nitrites were more likely to get certain cancers - specifically breast cancer and prostate cancer.[71].
OK, so what to make of all this? Well for me, that’s enough evidence to make me want to avoid processed meats, but … I’m gonna wait for more evidence on emulsifiers before I give up ice cream. And overall, there wasn’t quite enough research on other additives to freak me out too much. But then something came up that made me think, maybe I should throw out all the ultra-processed food from my pantry... so long, ramen?
That’s coming up after the break.
BREAK
BEAT 3– FOOD MATRIX
Welcome back. We just heard that ultra-processed food isn’t bad for us just because it’s junk food — there’s other stuff going on here. Including some of the sketchy additives that get tossed into the mix. But scientists told me - there’s probably more to it than that. On my journey to find out why processed food is bad for us, I kept hearing this phrase over and over again…from scientists all over the world[72][73][74]…
the food matrix
the food matrix
the food matrix
the food matrix
the food matrix is the main point
So I called up Cathrina [Katrina] Edwards, she’s a nutrition researcher at the Quadram Institute[75]…. Her job is to study food on a microscopic level. She loves looking at teeny slices of food under the microscope-- her favorite food to peek at is chickpeas…
CE The cell structure of chickpeas is and how beautiful they look under the microscope
RR Why do you think they are beautiful?
CE Well, I think it's the shape and they look very neat and organized. The plant cells are very well defined.
RR So it's sort of like the I'm imagining it's sort of like a stained glass
CE Yeah, yeah. It is a bit like that. ... You can stain it with dyes and it looks pretty colors
And Cathrina spends all this time at the microscope … to better understand the food matrix… which she told me is basically the structure of our food — how it’s put together … she said you can think of it this way:
CE you might experience it like something being crunchy or soft or hard or having a different feel to it. How it feels in the mouth is a big clue.[76]
Yeah big picture… when we process food, it’s a very noticeable texture change. Like, think of a single corn kernel – when it’s fresh… or dry… or popped! Different in your mouth– and if you were to zoom in– the tiny structures inside are also different. And scientists like Cathrina are looking at what that means down the line. Like - does this change how our body breaks food down? And if it does - could that be causing our ultra-processed food problems[77][78]?
Cathrina did a study several years back that could help us understand all this [79]. We’re gonna call it ... the chunky porridge pre-poop protocol. Buckle up.
OK, so the first thing they did was whip up two types of this wheat porridge. One was more processed - it was smoother. And one was less processed - it was chunkier. And they wanted to see what happened when people ate this stuff. Did the smooth stuff break down differently than the chunky stuff?[80]
CE: So, we wanted to understand if we preserve some of that structure, how is that digested? Especially how it was digested in the upper gut. The stomach and small intestine. The difficulty here is you can’t easily access the stomach and small intestine.
Yeah, it's not super accessible. Because this part of your gut is kind of coiled up behind your bellybutton[81]. It’s not like you can reach it by poking a finger up your butt. And Cathrina and her buddies really wanted to check out what was going on with the porridge here - because this is where the middle part of digestion happens - before food gets fully churned into poop! Because by the time it’s poop, the nutrients have already been absorbed, and everything kinda looks the same.
So they found the perfect group of people for their study: those who’d had a procedure called an ileostomy. Which can happen when the lower gut has a disease or some other issue and needs to be removed. A surgeon has to make an alternate exit route for food waste. So they go in …
CE And then they make a hole in the abdominal wall. So like, imagine like the front of your abdomen and then the small intestine is basically diverted to that opening.
The small intestine is re-routed so that the stuff inside comes out the side of the belly–
CE And then they're fitted with an external ileostomy bag, which is like a pouch.
So the remains of what people eat ends up in this little bag.
RR: Were you excited to be able to have kind of a window into the the middle part of digestion?
CE: Oh, it was so exciting, honestly. I think that the participants couldn't quite understand why we were so excited about getting this material. It's like gold dust, you know, to us. So it was fascinating.
Studying these people meant Cathrina’s group could kind of freeze frame this porridge mid-digestion - to see if anything was different between the more processed versus the less processed stuff as it made its way through the gut. So every two hours after people ate the porridge[82], they emptied out these bags and gave the stuff inside to Cathrina and her team.
RR: Was it as beautiful as the chickpeas?
CE: Oh, no, never. But very, very exciting. Very exciting, especially to see what came out. The other end was was very interesting.
RR: So, yeah, what did come up the other end, actually and like is it is it like poop at that point? Is it something different? It's something different.
CE: It's more it's more liquid.
CE: Mushroom soup, I would say
RR: Oh OK OK I can picture that uh huh
She took this soupy post-porridge and put it under the microscope… to find out if the body digested it differently depending on how processed it was. First she looked at the stuff that came out after people ate the smooth, highly processed porridge …She was looking for those little pieces of wheat. And she couldn’t see any sign of the stuff! There were no particles … but then when she looked at what was left of the chunky porridge….
CE It looked like what we'd put into the porridge was coming out the other end … y’know, we put 2-millimeter particles in, and 2-millimeter particles came out.
And what this suggests is that if the food matrix is all broken down and mushed up — it’s way easier for our body to digest– and we absorb the nutrients much faster. And for foods like wheat, that means the sugar we get from them can RUSH into our bloodstream instead of a gentle trickle. In fact, Cathrina looked at this in her study. They took blood samples from the participants. And they found that with the smooth - more processed - porridge, their blood sugar spiked more. By 12 percent[83].
CE And that's quite quite a big effect. So basically, if you eat coarse porridge, your blood sugar levels rise much less and more slowly than they would if you eat smooth porridge.
In the paper, Cathrina and her colleagues plotted this out in a beautiful graph– a line graph, the best kind– and you can see people’s blood sugar when they eat the smooth stuff has a higher rise and a bigger fall, compared to the less processed stuff.
Other studies have looked at different foods and found something similar:[84][85][86][87] The more processed, the faster the sugar or fat rushes into our bloodstream. And this could help explain why this stuff isn't great for us — because the more often your blood sugar is peaking and crashing and peaking and crashing– the higher the risk of getting type 2 diabetes[88] and heart disease.[89]
Cathrina is so convinced by this research that she said, if she was borderline diabetic, she’d probably avoid ultra-processed foods.
CE I think if I went to the doctor one day and they told me that then i would probably freak out a little bit and think, right, I need to get a hold of my diet. So It’s very individual, easy for me to sit here and say if I’ve been diagnosed with pre-diabetes or a metabolic syndrome or something that I’d be more careful about what I eat, but I do think there’s very convincing evidence.
BEAT 4 STUFF IN PACKAGING– HORMONE WACKADOODLE SOUP
Ok there’s one final thing we want to look at here. And it’s not about what we’re doing to the food itself– but it’s about what the food is served in. This is something that’s been all over the news[90][91]… concerning that modern day boogey man…plastics….
Plastics are messing with your hormones, this is a fact of modern life.
Potentially dangerous chemicals found in the food
So it’s the packaging that seeps into the food? That appears to be the case
There are freaky chemicals in plastics called endocrine disruptors. And they’re often found in stuff we store food in, like plastic containers. The big worry is that they can mess with our hormones. This is because they’re really similar to natural hormones - so they can attach to our hormone receptors[92][93] – and cause problems…
Some of them can affect things like how fetuses develop… or potentially screw with our fertility[94]…. and some can interfere with another hormone: insulin..[95]. And that helps explain why exposure to some of these chemicals has been linked to increased risk of diabetes.[96][97]
And these chemicals are a big problem for ultra-processed food …
SS: Basically what we've found is that the more processed a food is the more likely it can be to have these kinds of chemicals
This is Sheela Sathyanarayana. She’s a pediatrician and researcher at the University of Washington[98]. And Sheela says the trouble with many of the chemicals used to make plastics… is that they don’t stay in the plastic … Some of them are only loosely attached[99] , so they can pop off pretty easily.[100][101]
And there’s reason to think that people who eat a lot of ultra-processed food - are taking in more of these chemicals … this we know from studies on people’s urine… - that’s right! We’re going back to the bathroom.
RR we talked to someone about the effluent that came out of ileostomy bags and now we’re talking about pee this is a very potty related subject it seems like
SS yeah i'm very interested in the ileostomy and what they found that’s very interesting
RR haha must just be part of the course of food studies if you're interested in what people eat you have to think about it at the other end
SS You do that's the only way to really know [laugh]
The reason we need pee– is that’s how scientists check for these chemicals in our bodies. They break down and come out in our urine. And Sheela says some of the best evidence we have that more processed food has more of these chemicals comes from studies where scientists ask people what they’ve eaten in the past day or two and take urine samples from them. Sometimes these researchers ask about ultra-processed groceries. And sometimes they look at fast food, which tends to be ultra-processed.[102][103]
RR So they'll say did you have mcdonald's yesterday or jack in the box yesterday?
SS Basically are asking a generic question, did you have any fast food, and then they measure chemical concentrations in urine, and then they’ll compare those concentrations to people who did not report eating fast food
A study that came out a few years ago found that people who ate more fast food- had 20 to 40 percent more of some of these chemicals in their pee[104]. Studies also tend to find this in people who report eating a lot of ultra-processed food generally.[105].[106][107]… This could be because this food is hanging out in its packaging for a while before we eat it…[108] But it could ALSO be from stuff that happens in the factory[109][110]…
SS the way that I really think about it the more steps it takes to get the food to your plate, the higher the likelihood there is for contamination
We KNOW that a lot of the equipment in these factories is made with plastics that have these chemicals in them. Studies have found them in conveyor belts,[111] in storage tubs[112], and they’ve even been found in the gloves that workers wear when they touch the food[113]. At each step along the way there’s another chance for it to sneak into the food …. A good example is boxed macaroni and cheese[114][115]… Sheela’s like, just think about all the steps it takes to make that stuff…
SS let's just talk about macaroni first you have this wheat and it has to be harvested and then it has to be transported and then it has to be broken down into some kind of dough to make the macaroni and at each step in that process, there's the transport, there's the mixing, and I think people would be surprised how much plastic is used in each of those different steps
One advocacy group actually had some boxed mac n cheese analyzed - and found that the powdered cheese had at least twice as much of some of these chemicals as regular cheese[116].
And just overall - the more steps it takes to process a food, the greater the chances for it to get contaminated by whatever plastic it touches…
RR every time you add a step you're adding another order of magnitude of chaos almost
SS that's exactly how I think about it
So it makes sense that if you cut down on ultraprocessed foods, it’d help you avoid these gross chemicals. And you’d have less of this stuff in your pee. Sheela did a really striking study - that helps get at this.
Here’s what she did. A few years ago she and her team recruited some families in Seattle… just regular families, with a couple of kids, who ate a fair amount of canned and processed food. For the experiment, Sheela’s team had caterers deliver fresh, organic, made-from-scratch meals to their homes every day for a week[117] These were the kind of meals and snacks that nutritionists dream of. And Sheela and her colleagues tried to make sure no plastic touched the food at any point…
SS: We asked them in the kitchen when preparing foods use stainless steel bowls, blenders that were glass, food processors without plastic in them, and we asked them to use utensils that were not plastic
And they took pee samples from everyone in the family, even the little kids, before the study started, during the week of catered meals, and then after the week was up. So with most of the ultra processed foods removed from their diets for a week…and replaced with foods fit for Gwyneth Paltrow’s kitchen…Sheela figured these scuzzy chemicals in their pee would plummet…in fact a similar study done a few years before had found exactly that[118]– but– when the results came back for Sheela…something really unexpected happened. The chemicals in the families’ pee didn’t go down….
SS instead the levels increased during the intervention
RR That’s crazy!
SS It is crazy.
SS As a scientist my first thought was, how could this happen?
Yeah, how could this happen? Sheela analyzed foods from the caterers’ kitchen– and it turned out the chemicals were in the raw ingredients themselves. Like the cream and the butter - they had really high levels of this stuff …and so did one of the spices they used. And that’s because these chemicals can sneak into the food supply - in ways we’re not always thinking about. Like milk, it gets run from the cow’s udder through a bunch of tubes
SS if that plastic tubing has these chemicals in it, there could be contamination through that route[119]
RR So it’s really starting from the horse's mouth, to use bad analogy
SS right, right, well, that's what we think
Overall - this is bigger than us. We might be able to avoid some endocrine-disrupting chemicals by skipping ultra-processed foods. But generally….we’re all exposed to them[120][121]. They’re not just in the food system.. They’re used in all kinds of plastic, which are everywhere! So they’re kind of just always … around.
CONCLUSION:
OK, so where does all this leave us? Well, the science is pretty clear that the less we eat of this ultra-processed stuff, the better. But a lot of time when I hear people talk about this, they seem to want to go backwards– to go back to a time before the food supply was industrialized. And I don’t think that’s a good idea either. There is a lot to appreciate about the food system we have– like, making food at a huge scale that keeps a lot of us fed reliably. Plus, some large-scale processing makes food better. Going back to our white rice example from the beginning of the show– processing the rice caused the problem. But it also fixed the problem. Who do you think puts those B vitamins back? It’s not elves.
With all this in mind, I asked the scientists I spoke to for this episode if they had abandoned ultra-processed food altogether. Like, did it ruin Sheela’s love of stuff like potato chips?
SS it’s funny you say that I had some chips right before this call!
Yeah…most of the scientists I spoke to said…do your best but don’t sweat it toooo much….. Like when I asked Kevin if he avoids ultra-processed food, here’s what he said.
KH You know, I try, but I have two small boys at home who tend to kind of like their chicken fingers and their french fries, those sorts of things, and I end up eating a lot of their leftovers
RR How do you feel about that?
KH It is what it is, we all do our best to kind of make healthy choices but the day to day practicalities weigh on everybody. Of course, if I could hire a personal chef and have access to a nice little farm in my backyard, and prepare unprocessed meals for my whole family, that would be great, but life just didn't provide that for me yet [laughs].
That’s Science Vs.
CITATIONS
This episode was produced by me, Rose Rimler with help from Michelle Dang, Meryl Horn, Ekedi Fausther-Keeys, Courtney Gilbert, and Rasha Aridi. Our executive producer is Wendy Zukerman. We’re edited by Blythe Terrell. Fact checking by Erica Akiko Howard. Mix and sound design by Bumi Hidaka. Music written by Bumi Hidaka, Peter Leonard, Emma Munger, Marcus Bagala, and Bobby Lord. Thanks to all the researchers we got in touch with for this episode, including Dr. Anthony Fardet, Dr. Bernard Srour, Prof. Jose Miguel Aguilera, Dr. Mathilde Touvier, Dr. Melissa Melough, Dr. Rachel Laudan, Prof. Niyati Parekh, and lots of others. Special thanks to Paul Adams.
[1] “Since the 1870s there had been the rapid growth of mechanized rice-milling. Instead of de-husking by hand, rice was now processed in power-driven mills, which, along with the husk, removed the inner skin or pericarp, the grain then being further buffeted to produce a polished, white appearance.”
[2] Pervez & Zakiuddin (2018) identify one from the 1860s, another in 1870, then another around 1890, pp.
91-95. (Sci-Hub)
[3] Polished white rice was rare and expensive, but it was around well before the industrial machines were developed. Li and Dray-Novey (1999) refer to grain tributes that included white rice at least as early as the 1700s in China. White rice could be produced laboriously by hand pounding (although this process didn’t necessarily strip all the thiamine out…). Mentions of beriberi in Japan go back to at least the Edo period – some wealthy urbanites got rice polished by water mills (see Hokusai print of “Rice polishing by water mill in early modern Japan” dated c. 1830.)
Bay (2008), p. 114: “In the premodern capital of Edo, beriberi was known as the affliction of Edo… Katsuki Gyuzan … (1656-1740) noted that this affliction was widespread among both the warrior and the commoner classes in 1699.”
Bay (2008), p. 129: “ In 1918 the Yomiuri shinbun served as a platform for Toyama to publicize his ideas. In a series of articles entitled "The Japanese and White Rice," he told how the Japanese had traditionally eaten brown rice. ‘…this rice has not always been white rice like we eat today, but brown rice. . . . Only high-ranking people within the elite class ate white rice [during the Edo period]. While culture advanced rapidly during the Genroku era [1688-1703], everyone outside of Edo, Kyoto, or Osaka was eating unpolished brown rice.’ ”
[4] Among the effects: “… Edema, or dropsy, commonly progresses until the lower extremities and the face are swollen. Pain and sensitivity in the calf muscles is an early sign as muscles begin to swell, degenerate, and atrophy. … Edema of the lungs often causes sudden respiratory distress and, with heart failure, death.” … “In chronic beriberi, there is progressive degeneration of nerve fibers. … Sensibility to tactile stimulation, then to pain, and finally to temperature is lost. The motor nerves are next affected, with paralysis beginning in the lower extremities. Then the fingers are affected, the hand drops limp at the wrist, and the fingers contract into a claw hand. … Other symptoms that commonly occur include a full sensation or cramping of the epigastrium, heartburn, constipation, and mental confusion…”pp. 608-9, The Cambridge World History of Human Disease, (2008), Meade: “VIII.15 – Beriberi” from “Part VIII - Major Human Diseases Past and Present”
[5] “In classic beriberi, death results eventually from severe disturbances of the circulatory system and paralysis of the respiratory muscles ending in heart failure.” p. 609, The Cambridge World History of Human Disease, (2008), Meade: “VIII.15 – Beriberi” from “Part VIII - Major Human Diseases Past and Present”
[6] Alexander R. Bay, 2012, Beriberi in Modern Japan: The Making of a National Disease, p. 32: “The Meiji Emperor had a personal and immediate interest in beriberi not simply because he himself was afflicted; many in the imperial family suffered from it as well.10 Princess Chikako, for example, fell ill in June 1877…In August, the princess’s symptoms worsened, and she quickly succumbed to the disease.12” Publisher: Boydell & Brewer, University of Rochester Press Series: Rochester Studies in Medical History
[7] “beriberi caused 8.2 percent of the total number of deaths from disease per year. On average, 265,000 people developed beriberi: between five and seven out of every one thousand people fell ill with beriberi, and one or two of those afflicted died from the disease.” Source: Bay, Beriberi in Modern Japan, Ch. 4, p. 89, https://www.jstor.org/stable/10.7722/j.ctt1x745m.9
[9] Thiamine (Vitamin B1) in 100 g of cooked, medium-grain brown rice: 0.102 mg… vs. in 100 g of cooked, medium-grain UNENRICHED white rice: 0.02 mg
“There are 13 essential vitamins — vitamins A, C, D, E, K, and the B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, B6, B12, and folate).”
[10] e.g., “FDA data indicate that the use of AFCs [artificial food colors] increased more than fivefold between 1950 and 2012, from 12 to 68 mg per capita per day”
[11] “The consumption of ultra-processed foods increased among all US adults from 2001–2002 to 2017–2018 (from 53.5 to 57.0 %kcal; P-trend < 0.001)” (%kcal is “the relative contribution to daily energy intake”)
[12] Monteiro, C.A., Cannon, G., Lawrence, M., Costa Louzada, M.L. and Pereira Machado, P. 2019. Ultra-processed foods, diet quality, and health using the NOVA classification system. Rome, FAO.
[13] “Ultra-processed foods are formulations of ingredients, mostly of exclusive industrial use, typically created by series of industrial techniques and processes (hence ‘ultra-processed’). Some common ultra-processed products are carbonated soft drinks; sweet, fatty or salty packaged snacks; candies (confectionery); mass produced packaged breads and buns, cookies (biscuits), pastries, cakes and cake mixes; margarine and other spreads; sweetened breakfast ‘cereals’ and fruit yoghurt and ‘energy’ drinks; pre-prepared meat, cheese, pasta and pizza dishes; poultry and fish ‘nuggets’ and ‘sticks’; sausages, burgers, hot dogs and other reconstituted meat products; powdered and packaged ‘instant’ soups, noodles and desserts; baby formula; and many other types of product.”
[15] “NutriNet-Santé is a large-scale (n=171,000) web-based cohort coordinated by EREN, launched in France in 2009 to investigate nutrition and health relationships. All required ethics authorisations have been obtained (listed here). NutriNet-Santé participants regularly fill questionnaires through a dedicated and secure website, providing extensive, high-quality nutritional and non-nutritional data, including repeated data on socio-demographics and lifestyle (yearly), anthropometrics (every 6 months), dietary intake (every 6 months), physical activity (IPAQ questionnaire, yearly)5 and health status (every 6 months). NutriNet-Santé is characterised by a very detailed and up-to-date assessment of nutritional exposure and dietary behaviours. Usual dietary intakes are assessed at baseline and every 6 months thereafter through a series of 3 non-consecutive randomly assigned 24h dietary records. Daily energy, alcohol, micro- and macronutrient intakes are calculated using the published NutriNet-Santé food composition database (>3,500 generic items). All major health events (e.g., cancers, cardio- and cerebrovascular diseases) are reported by the participants and validated by an expert committee of physicians based on medical records, and/or retrieved from the French National Health Insurance medico-administrative databases to limit potential reporting bias. In turn, mortality data are obtained from the exhaustive French National Mortality Registry (CépiDC). The number of incident events already registered is as follows: 4,200 cancers and 1,240 deaths. A sub-sample of the cohort (n=20,000) provided blood and urine samples, currently stored at -80°C in EREN's biobank.”
[16] Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort | The BMJ: “a 10% increase in the proportion of ultra-processed foods in the diet was associated with a significant increase of greater than 10% in risks of overall and breast cancer”: “increases of 12% in the risk of overall cancer and 11% in the risk of breast cancer”
[17] Ultra-processed food intake and risk of cardiovascular disease: prospective cohort study (NutriNet-Santé): “In this large prospective cohort, an absolute increment of 10 in the percentage of ultra-processed foods in the diet was associated with a 12%, 13%, and 11% statistically significant increase in the rates of overall cardiovascular, coronary heart, and cerebrovascular disease, respectively.”
[18] Ultraprocessed Food Consumption and Risk of Type 2 Diabetes Among Participants of the NutriNet-Santé Prospective Cohort: “Consumption of UPF [ultra-processed foods] was associated with a higher risk of T2D [type 2 diabetes] (multi-adjusted hazard ratio [HR] for an absolute increment of 10 in the percentage of UPF in the diet, 1.15; 95% CI, 1.06-1.25; median follow-up, 6.0 years; 582 252 person-years; 821 incident cases). These results remained statistically significant after adjustment for several markers of the nutritional quality of the diet, for other metabolic comorbidities (HR, 1.13; 95% CI, 1.03-1.23), and for weight change (HR, 1.13; 95% CI, 1.01-1.27).” (A HR value of 1.15 corresponds to a 15% increase in T2D risk.)
[19] Association Between Ultraprocessed Food Consumption and Risk of Mortality Among Middle-aged Adults in France “A total of 602 deaths (1.4%) occurred during follow-up. After adjustment for a range of confounding factors, an increase in the proportion of ultraprocessed foods consumed was associated with a higher risk of all-cause mortality (HR per 10% increment, 1.14; 95% CI, 1.04-1.27; P = .008).”
[20] “A high proportion of UPF [ultra-processed food] in the diet was associated with increased risk of CVD and all-cause mortality, partly through its high dietary content of sugar.” “in a large sample of the Italian adult population” (PDF also here)
[21] Study of 12,000 people in Spain found risk of death increased by about 45% in people who ate the most UPF compared to those who ate the least, when adjusted for age, etc.
[22] A study of >21,000 people in the UK found that for every 10% more UPF in diet, type 2 diabetes went up 12%, adjusted for lots of stuff including BMI
[23] 11,000 US adults from NHANES survey 2011-2016 “Every 5% increase in calories from UPFs [ultraprocessed foods] was associated with 0.14 points lower CVH [cardiovascular health] score (P < 0.001).”
[24] NHANES study evaluating data from late 80s early 90s (N = ~12,000) found that “Over a median follow-up of 19 years, individuals in the highest quartile of frequency of ultra-processed food intake (e.g. sugar-sweetened or artificially sweetened beverages, sweetened milk, sausage or other reconstructed meats, sweetened cereals, confectionery, desserts) had a 31% higher risk of all-cause mortality, after adjusting for demographic and socio-economic confounders and health behaviours”
[25] “When considered in relation to other food groups, an inverse linear relation between UPFs and less-processed foods was evident. Increased UPF intake correlated with an increase in free sugars, total fats, and saturated fats, as well as a decrease in fiber, protein, potassium, zinc, and magnesium, and vitamins A, C, D, E, B12, and niacin. In conclusion, the data indicate that increased UPF consumption negatively affects the nutritional quality of diets.”
[26] “The content of added sugars in ultra-processed foods (21.1% of calories) was eightfold higher than in processed foods (2.4%) and fivefold higher than in unprocessed or minimally processed foods and processed culinary ingredients grouped together (3.7%).”
[28] Menus available in supplemental material: https://www.cell.com/cms/10.1016/j.cmet.2019.05.008/attachment/f7d43756-3f67-4557-8322-59a9d143d63c/mmc1.pdf
[29] “Interestingly, Figure 2F illustrates that meal eating rate was significantly greater during the ultra-processed diet whether expressed as kcal/min (17±1 kcal/min; p<0.0001) or g/min (7.4±0.9 g/min; p<0.0001). Individual differences in average eating rate in kcal/min between the ultra-processed and unprocessed diets were moderately correlated with overall energy intake differences (r= 0.45; p=0.047).”
[30] From our episode on weight/health: “People with high BMIs are more likely to have health problems like heart disease[34], type 2 diabetes[35], and some kinds of cancer[36]”
34: The famous Framingham heart study (mostly white, middle class Americans) which followed people for decades-- found that risk of heart disease increased 20% in overweight people and increased 40-60% in obese people.
35: Ten-year followup data from the Nurse’s Health Study and a similar one in men found that risk of heart disease and diabetes were higher in people with higher BMIs, with diabetes risk much higher than heart disease.: see Table 3
36: From a study of over 5 million people in the UK followed over two decades: With BMI included as a linear effect, and adjusting for all potential confounders, each 5 kg/m2 increase in BMI was associated with a large increase in risk of cancer of the uterus (HR 1·62, 99% CI 1·56–1·69; figure 2). There were also large increases in risk (HR >1·1 per 5 kg/m2) for cancers of the gallbladder, kidney, and liver, and small increases in risk for colon, cervical, thyroid, ovarian, and postmenopausal breast cancers and leukaemia (figure 2).
[31] “However, the associations between ultra-processed food intake and risk of cancer observed in this study were statistically significant despite adjustment for body mass index and remained significant after further adjustment for a Western-type dietary pattern and/or the energy, fat, sugar, and salt content of the diet.” In Table 2: “Model 1=multivariable Cox proportional hazard model adjusted for age (timescale), sex, energy intake without alcohol, number of 24 hour dietary records, smoking status, educational level, physical activity, height, body mass index, alcohol intake, and family history of cancers” (France)
[32] “In model 1 (adjusted for age (timescale), sex, BMI, physical activity level, smoking status, number of 24 hour dietary records, alcohol intake, energy intake, family history of CVD [cardiovascular disease], and educational level), during a median follow-up of 5.2 years, intake of ultra-processed food was associated with increased risks of overall CVD (hazard ratio for an absolute increment of 10 in the percentage of ultra-processed foods in the diet 1.12 (95% confidence interval 1.05 to 1.20); P<0.001, 518 208 person years” (France)
[33] See table 2 and table 3, models adjusted for baseline BMI: https://academic.oup.com/ajh/article/30/4/358/2645510 (Spain)
[34] “Of note, energy balance and overweight are both associated with T2D [type 2 diabetes] risk. However, this could not have entirely explained the associations observed because our models were adjusted for BMI and weight change.” (France)
[35] See table 3 https://link.springer.com/article/10.1186/s12916-019-1312-y/tables/3 Model 1 adjusted for age, sex, and body mass index (France)
[38] “The Pew Research Center survey finds the U.S. public of two minds about food additives. Roughly half say the average person faces a serious health risk from food additives over their lifetime (51%) while the other half believes the average person is exposed to potentially threatening additives in such small amounts that there is no serious risk (48%).”
[39] Pg 221: “To prevent lipid oxidation in foods from meat products to nuts, developers add natural polyphenolic compounds such as tocopherols (vitamin E)... Among the natural antioxidants, mixed tocopherols are commonly used. These are eight naturally occurring compounds (a mixture of tocopherols and tocotrienols) related to vitamin E that are commercially extracted from vegetable oils.” (from Ch 12 “Food Additives” in Culinology: The Intersection of Culinary Art and Food Science, Wiley, 2016, editor: J.J. Cousminer)
[40] The WHO evaluated tocopherols in their 1973 review: “Though the toxicological studies are less than would normally be required for foreign substances used as food additives, it is considered that alpha-tocopherol is a nutrient. The clinical experience with this vitamin is used as the basis for the evaluation.”
[41] Pg 236: “Autolyzed yeast extract is used primarily as a flavor enhancer in processed foods such as soups, meats, and vegetarian meat analogs. Like MSG, it is valued for its ability to stimulate taste receptors that are sensitive to the umami or savory type of taste” (from Ch 12 “Food Additives” in Culinology: The Intersection of Culinary Art and Food Science, Wiley, 2016, editor: J.J. Cousminer)
[43] “Ultra-processed foods are basically confections of group 2 ingredients, typically combined with sophisticated use of additives, to make them edible, palatable, and habit-forming. They have no real resemblance to group 1 foods, although they may be shaped, labelled and marketed so as to seem wholesome and ‘fresh’. Unlike the ingredients included in group 2, ultra-processed foods are typically not consumed with or as part of minimally processed foods, dishes and meals. On the contrary, they are designed to be ready-to-eat (sometimes with addition of liquid such as milk) or ready-to-heat, and are often consumed alone or in combination (such as savoury snacks with soft drinks, bread with burgers).”
[44] From a 2009 letter: “In his recent invited commentary, Carlos Monteiro proposes a classification of foods based on the type and intensity of food processing. In particular, he identifies a category of ‘ultra-processed foods’, the consumption of which should be avoided to prevent disease and enhance well-being. In his fairly provocative title, he states that ‘The issue is not food, nor nutrients, so much as processing’.”
[45] US Food and Drug Administration’s “Substances Added to Food” database currently lists 3,975, but “It is important to note that the inventory is only a partial list of food ingredients.”
[46] “More than 10 000 chemicals are allowed to be added to food in the United States, either directly or indirectly, under the 1958 Food Additives Amendment to the 1938 Federal Food Drug and Cosmetic Act (Public Law 85-929). An estimated 1000 chemicals are used under a “Generally Recognized as Safe” (GRAS) designation without US Food and Drug Administration (FDA) approval or notification.” (More here)
[47]FDA spokesperson in email to RR: “The agency performs a science-based evaluations of the safety data, including data available in the published scientific literature to ensure safety of the substance at use levels that approximate what humans may consume in their diets. Most safety studies are performed in rodents and the results are extrapolated to humans. This is because the relevant safety endpoints involve analyzing tissue or organs (things that cannot be done in humans). ….The term “food additive” is defined in the 1958 amendments to the FD&C Act. As part of that law there is an exclusion to the FDA's premarket approval authority for food additives for GRAS (Generally Recognized as Safe) substances. A company may conclude that, based on publicly available information, the intended use of substance in food is GRAS. We encourage manufacturers to submit their GRAS conclusions to FDA for review; however, the FD&C Act does not require FDA approval of GRAS conclusions. “
[48] E.g., “Based on the available scientific evidence and the findings of expert scientific panels, the Food and Drug Administration (FDA or we) has made a final determination that there is no longer a consensus among qualified experts that partially hydrogenated oils (PHOs), which are the primary dietary source of industrially-produced trans fatty acids (IP-TFA) are generally recognized as safe (GRAS) for any use in human food.”
[49] “Because of inherent limitations of science, FDA can never be absolutely certain of the absence of any risk from the use of any substance. Therefore, FDA must determine - based on the best science available - if there is a reasonable certainty of no harm to consumers when an additive is used as proposed.”
[50] “Emulsifiers constitute an important class of food ingredients that are used in a variety of foods, and are reported to represent approximately 75% of all approved food ingredients on the market (JECFA, 1998).”
[51] https://academic.oup.com/nutritionreviews/article-abstract/79/6/726/5867654 | scihub “Given the ubiquity of food additive emulsifiers in the food supply …”
[52] https://academic.oup.com/nutritionreviews/article-abstract/79/6/726/5867654 scihub see table 2 for ice cream, dressing, and cookie examples (and many others): e.g., Dairy-based ice cream and frozen desserts (Carrageenan); Dairy-based ice cream and frozen yogurt (Mono- and diglycerides of fatty acids); Dressings and vinegar (Xanthan gum); Cakes, pastries, and sweet goods (Mono- and diglycerides of fatty acids); Water-based ice popsicles and sorbets (Celluloses, including carboxymethylcellulose); Water-based frozen desserts (Guar gum)
[53] https://onlinelibrary.wiley.com/doi/full/10.1111/nbu.12408 Also see table 2: e.g., ice cream shows up in several categories; plus lots of others (e.g., cookies, salad dressing)
[54] Helpful overview: https://theconversation.com/food-additives-and-chronic-disease-risk-what-role-do-emulsifiers-play-38492#:~:text=A%20recent%20study%20suggests%20emulsifiers,our%20risk%20of%20chronic%20disease.
[55] “...we observed that administration of CMC [carboxymethylcellulose] and P80 [polysorbate 80] to mice
resulted in microbiota encroachment into the mucus, alterations in microbiota composition, including an increase of bacteria that produced proinflammatory flagellin (FliC) and lipopolysaccharide (LPS), and development of chronic inflammation…” “We examined the direct impact of CMC and P80 on the microbiota using the mucosal simulator of the human intestinal microbial ecosystem (M-SHIME) model that maintains a complex stable human microbiota in the absence of a live host.” “This model consists of consecutive pH-controlled, stirred (200 rpm), airtight, double-jacketed glass vessels kept at 37°C and under anaerobic conditions by daily flushing with N2 (15 min). The set-up used in this study consisted of a stomach and a small intestine vessel and eight (experiment represented figures 3–⇓ 5, 7–⇓ 9 and online supplementary figures S1–S13) or nine (experiment represented figure 6) proximal colon vessels in parallel.”
[56] “In accordance with previous studies, both carboxymethylcellulose and polysorbate 80 induced a lasting seemingly detrimental impact on microbiota composition and function. While many of the other 18 additives tested had impacts of similar extent, some, such as lecithin, did not significantly impact microbiota in this model. Particularly stark detrimental impacts were observed in response to various carrageenans and gums, which altered microbiota density, composition, and expression of pro-inflammatory molecules.” “These results indicate that numerous, but not all, commonly used emulsifiers can directly alter gut microbiota in a manner expected to promote intestinal inflammation.”
[57] “Translocation of E coli across M-cells is reduced by soluble plant fibres, particularly plantain and broccoli, but increased by the emulsifier Polysorbate-80. These effects occur at relevant concentrations and may contribute to the impact of dietary factors on Crohn's disease pathogenesis.”
[58] “...CMC [carboxymethylcellulose] consumption …perturbed gut microbiota composition in a way that reduced its diversity.” “the relative abundance of these SVs [sequence variants] were markedly affected by CMC consumption, including decreases in Faecalibacterium prausnitzii and Ruminococcus sp., and increases in Roseburia sp. and Lachnospiraceae (Supplementary Figure 6). Although it is difficult to reliably ascribe functional consequences to these alterations, we note that CMC consumption induced loss of F. prausnitzii, which is associated with health and known to mediate production of beneficial metabolites such as short-chain fatty acids”
[59] E.g., “Emerging in vitro and animal evidence suggests that food additives such as emulsifiers may contribute to gut and metabolic disease development through alterations to the gut microbiota, intestinal mucus layer, increased bacterial translocation and associated inflammatory response.”
[60] “The dose of CMC (15 g per person per day) used in this study likely exceeds CMC intake of most individuals but might approximate the total amount of emulsifier consumption by persons whose diets are largely comprised of highly processed foods that contain numerous emulsifiers…”
[61] “Our analyses indicated that among the emulsifiers assessed, lecithin and MDGs have the highest mean exposures at about 60 and about 80 mg kg-1 bw day-1, respectively, whereas the exposure to CMC is half to one-third that of lecithin or MDGs; and the exposure to P80 is approximately half that of CMC. The review of available safety information such as ADIs established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), in light of our updated dietary exposure estimates for these seven emulsifiers, did not raise safety concerns at the current specified levels of use. Additionally, by examining two time periods (1999-2002, 2003-10), it was concluded that there is no evidence that exposure levels to emulsifiers have substantially increased.”
[62] “A literature search was conducted which identified eight studies investigating the interaction of sodium carboxymethyl cellulose, polysorbate 80, gum arabic, carrageenan, and arabinogalactan with the gut microbiota in murine and in vitro models. … These studies were conducted at high doses that have no relevance to the current dietary levels consumed in the United States”
[63] “For example, the nutrition group from the International Organization for the Study of Inflammatory Bowel Disease (IOIBD) has recently published dietary recommendations for patients with IBD (42). Though the evidence base is limited, it was recommended that patients with Crohn’s and UC limit consumption of certain commonly encountered emulsifiers, specifically carboxymethylcellulose (E466/cellulose gum) and polysorbate-80 (E433) (see Table 1 for food sources of these additives) both for Crohn’s disease and Ulcerative Colitis (42). Both emulsifiers are present in many processed foods, such as ice cream. The group also recommends a decrease in foods containing carrageenan, a commonly used emulsifier/stabilizer. It is very hard to take issue with these consensus recommendations.”
[64] “In CD [Crohn’s disease], it may be prudent to reduce intake of processed foods that contain carrageenan, carboxymethylcellulose, and polysorbate-80 (EL [evidence level] very low). In UC [ulcerative colitis], it may be prudent to reduce intake of processed foods that contain carrageenan, carboxymethylcellulose, and polysorbate-80 (EL very low).” (sci-hub)
[66] Consumer Reports: We tested 31 packaged deli meats—name brands and store brands—including chicken, ham, roast beef, salami, and turkey. (See “CR’s Deli Meat Test Results,” below.)
All samples had levels below the federal government’s thresholds for deli meats: 500 micrograms per gram for nitrate and 200 micrograms for nitrite. But our tests also showed how confusing the labels can be. There were 10 “cured” meats in our tests and 21 “uncured.” On average, the nitrate and nitrite levels were essentially the same.
[67] Relating to the overall nitrite and nitrate levels, Bresaola showed the highest levels, followed by Speck. Lower levels were detected in Mortadella, cooked meat and cooked ham. The lowest concentrations of nitrite/nitrate were registered in canned meat.
[68] Table 2 Nitrates; Table 3 Nitrites - Sausage, Bacon, Processed Meats
“The highest median nitrate content is observed in chorizo (median [IQR]; 101.61 [60.05–105.93] mg kg-1). Canned fish products have the highest median nitrite level (median [IQR]; 20.32 [6.16–30.16] mg kg-1). By subgroup, the median nitrate value in industrial processed meat products (e.g., uncured burger, patties and sausages), whole milk powder and in particular red meat are higher than cured meat products.”
[69] "Regarding side effects, the Scientific Committee for Food of the EU (Directive 2008/7/CE, 2008), in 22 September 1995 reported that in meat products nitrates turn into nitrites (e.g., by heating). Nitrites, in turn, react with acids (for example the existing hydrochloric acid in the stomach) and lead to the formation of nitrous acid (HNO2), which in turn can react with certain amines (obtained by the hydrolysis of proteins) and form nitrosamines (Directive 2008/7/CE, 2008). Moreover, nitrosamines are genotoxic carcinogens and there is no threshold below which the formation of cancerous cells and tumors can be excluded (Oficial Journal of the European Union, 1999)."
[70] “In 2006, the International Agency for Research on Cancer classified ingested nitrates and nitrites, in situations that would lead to endogenous nitrosation (production of NOCs), as “probable human carcinogens” (Group 2A)” [Sci-hub]
[72] “The term “food matrix” has appeared in the food technology and nutrition literature to denote that chemical compounds in foods behave differently in isolated form (e.g., in solution) than when forming part of food structures. … Differences among food matrices are largely responsible for the nutritional performance and health potential of products that have similar chemical composition (Fardet 2014; Capuano, Oliviero, and van Boekel 2017).” sci-hub
[73] “Processing induces significant changes to the food matrix, for which ultra-processed foods may affect health outcomes differently than unrefined whole foods with similar nutritional composition.”
[74] “We postulate that if the nutrient content is insufficient to fully characterize the diet-global health relationship, one other dimensions is necessary, i.e., the food matrix through the degree of processing.”
[76] “The term food matrix describes the physical form of a food, and encompasses the natural structures of raw plant materials as well as the composite organisation that results from industrial and/or household processing(27,28). For edible plants, the scales range from the cm scale of plant tissues to the nm dimensions of nutrients and phytochemicals inside plant cells”
[77] “Processing induces significant changes to the food matrix, for which ultra-processed foods may affect health outcomes differently than unrefined whole foods with similar nutritional composition. Notably, the highly degraded physical structure of ultra-processed foods may affect cardiometabolic health by influencing absorption kinetics, satiety, glycemic response, and the gut microbiota composition and function.”
[78] “We postulate that if the nutrient content is insufficient to fully characterize the diet-global health relationship, one other dimensions is necessary, i.e., the food matrix through the degree of processing”
[79] Cathrina Edwards’s study (note: was done at King’s College London, not Quadram Institute where she is now): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4588739/
[80] Note: Both kinds of porridge were smooth enough to slurp down comfortably without chewing. In fact, they asked people not to chew, just to minimize differences between the two. But Cathrina does not advise that people reduce chewing their food to reduce blood sugar spikes–there’s no evidence this would work–and it could be dangerous. - Pers. Comm.
[81]https://my.clevelandclinic.org/health/body/22135-small-intestine#:~:text=Where%20is%20the%20small%20intestine,edges%20of%20the%20abdominal%20cavity.
[82] Fig. 1: “ileal effluent was collected every 2 h up to 10 h" "then at the participants' convenience overnight"
[83] “Blood glucose, insulin, C-peptide, and glucose-dependent insulinotropic polypeptide concentrations were significantly lower (i.e., 33%, 43%, 40%, and 50% lower 120-min incremental AUC, respectively) after consumption of the coarse porridge than after the smooth porridge (P < 0.01).” … “The peak concentrations of glucose, insulin, C-peptide, and GIP were 12%, 32%, 37%, and 60% higher (P < 0. 01), respectively, after smooth than after coarse porridge and were reached within 90 min of ingesting the test meals.”
[84] “Recent studies have demonstrated the importance of food structure during the digestion of plant foods. In particular, in the almond kernel, depending on its structure and degree of processing, the amount of lipid released from the almond tissue matrix and the fatty acids produced from lipolysis has been found to vary substantially. … Differences in the physical form of ingested almonds in particular, lead to variability in nutrient digestibility and consequently evoke different blood nutrient profiles and gut hormone responses.”
[85] “Here we show that the integrity of cell wall fibre in chickpea powder was preserved on baking and this led to a ~40% reduction in in vivo glycaemic responses (iAUC120) to white bread rolls (~50 g available carbohydrate and 12 g wheat protein per serving) when 30% or 60% (w/w) of the wheat flour was replaced with intact cell powder.”
[86] “As predicted, the low-lipid-bioaccessibility meal (WA [whole almond seed macroparticles]) resulted in a significantly attenuated lipemic response compared with the high-lipid-bioaccessibility meals (AO [almond oil and defatted almond flour] and CO [sunflower oil blend as control]). The substantially lower iAUC [incremental area under curve] value for triacylglycerol after the WA meal (ie, a 74% reduction relative to AO; see inset in Figure 1) was consistent with the predicted low level of lipid release for WA, which was estimated to be ≈8–12% (22). We attributed this effect to the structurally intact cell walls of almonds, which act as a physical barrier and thereby encapsulate the intracellular lipid and hinder the lipid release during digestion. Indeed, direct evidence for a cell wall barrier mechanism comes from in vitro digestion experiments of almond lipid (16) and from a human study showing that the ingestion of almond seeds increases the fecal excretion of encapsulated lipid (7).”
“Concentrations reached peak values 5 h after all test meals, increasing from mean fasting values (%) of 40.6 (95% CI: 24.9, 58.4), 115.3 (95% CI: 84.4, 151.5), and 103.0 (95% CI: 77.1, 132.7) after the WA, AO, and CO meals, respectively.”
[87] Study looking at oatmeal particle size: The flake porridge gave a lower glucose response than the flour porridge, and there were apparent differences in gastric emptying in both the early and late postprandial phases.
[88]There was a positive association between dietary GI and the risk of type 2 diabetes, coronary heart disease, and colorectal, breast, and bladder cancers, as well as between dietary GL and the risk of coronary heart disease, type 2 diabetes, and stroke.
[89] Glycemic variability (GV), referring to oscillations in blood glucose levels. … There is considerable evidence to support the negative role of GV in the development of diabetic macrovascular and microvascular complications … Moreover, a meta-analysis conducted by Liang et al. reported that high amplitude of GV played a causal role in cardiovascular disease (CVD), and minimizing GV could improve insulin resistance and reduce carotid intima-media thickness, as well as lower the risk of CVD
[90]https://www.consumerreports.org/pfas-food-packaging/dangerous-pfas-chemicals-are-in-your-food-packaging-a3786252074/ (refers to PFASs – per- and polyfluoroalkyl substances – which are “endocrine disrupting halogenated pollutants”)
[92] “BPA has been the focus of significant research and attention. It can bind to the estrogen receptor and cause tissues to respond as if estradiol is present; thus, it is classified as an “endocrine disruptor.” ” (sci-hub)
[93] “Endocrine-disrupting chemicals (EDCs)... can mimic or inhibit naturally occurring hormones by binding classical nuclear hormone receptors or by disrupting other pathways regulating hormone synthesis or action, thereby disrupting the normal physiology and homeostasic processes of the organism”
[95] “Diabetes mellitus is characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. Any toxic chemical that kills β-cells or disrupts their function has been termed a “diabetogen.” Beginning more than 30 years ago, researchers described how environmental chemicals (eg, dioxins, DDT, BPA) altered β-cell function (168–171). Recently, numerous articles have been published demonstrating the link between EDC exposure and alterations in glucose homeostasis and/or diabetes mellitus in animals as well as epidemiological studies in humans (138, 172–175).”
”Here we will review the evidence published since 2008 implicating EDC exposure in the etiology of obesity and T2D. It is difficult to know which EDCs are risk factors for obesity, diabetes, or both, because they have interlinked pathologies. However, there is enough evidence to suggest that some EDCs act as obesogens and others act as diabetogens (Table 3).” “The etiology of type 1 diabetes mellitus (T1D) is very different from T2D. … Studies relating EDCs and other contaminants to T1D are beginning to emerge, although they are still very preliminary”
[96] Discussion of French all-cause mortality study about ultraprocessed foods mentions BPA/endocrine disruptors (cancer, diabetes, obesity): “Epidemiologic data have suggested that endocrine disruptors are associated with an increased risk of endocrine cancers and metabolic diseases, such as diabetes and obesity.”
[97] “Endocrine-disrupting chemicals (EDCs)... disrupt cellular and whole-body metabolism… recent research has identified exposures to these metabolism-disrupting chemicals (MDCs) as playing a causative role in a wide spectrum of metabolic disorders in humans, including obesity, diabetes, dyslipidemia, nonalcoholic fatty liver disease (NAFLD), and cardiovascular dysfunction”.
[98] https://deohs.washington.edu/faculty/sheela-sathyanarayana ; https://www.seattlechildrens.org/directory/sheela-sathyanarayana/
[99] “Because they are not chemically-bound, phthalates and bisphenols used in food contact materials or food processing plastics can transfer to food (Koch and Calafat, 2009).”
[100] “Seafood samples packed in polypropylene (PP), polyvinyl chloride (PVC), tin can, and glass containers were monitored for 4 months to determine the time-dependent migration of phthalate esters (DEHP, DBP, BBP, DINP, DIDP, and DNOP). DEHP was the most phthalate esters found in food samples…Unfortunately, all three packaging materials have an active role in the migration of phthalate esters into foodstuff.”
[101] “We investigated the release of phthalates and heavy metals in coffee brewed from coffee packed in single-serve coffee containers made from different types of materials: metal, biodegradable and plastics. We detected with GC–MS small amounts phthalates, below the tolerated daily risks levels, in all the coffees prepared from the different types of capsules.” “Plasticizers such as phthalate esters, because of their anti-androgen and estrogen-like activity, are indicated as major endocrine disruptors”
[102] In the studies that evaluated dietary patterns, the ultra-processed groups included snacks (like crisps or chocolates), sweets, convenience foods and fast foods( Reference Ritchie, Spector and Stevens28 ); snacks and convenience foods( Reference Diethelm, Günther and Schulze35 ); fast foods (sweetened beverages, French fries, fried chicken, salted snacks, hamburgers, hotdogs and pizzas)( Reference Shang, O’Loughlin and Tremblay36
[103] Of the sample of food ads, PUPF [processed and ultra-processed food ]products were more frequently advertised during children’s programmes (98·9 %) v. programmes targeted to the general audience (93·7 %, χ 2=45·92, P<0·01). The top five food categories were desserts, dairy products, non-alcoholic sugary beverages, fast-food restaurants, and salty snacks. [fast-food was treated as a category of PUPF- see table 3 (food processing level categorized according to the NOVA system)]
[104] https://pubmed.ncbi.nlm.nih.gov/27072648/ “In this cross-sectional study of the U.S. population, we found a consistent, positive association between recent fast food consumption and phthalates exposure. Furthermore, there was evidence of a monotonic, positive dose–response; participants with high fast food intake had 20–40% higher urinary concentrations of phthalate metabolites than did nonconsumers. … We did not find an association between total fast food consumption and BPA.” “...participants with high consumption (≥ 34.9% TEI [total energy intake] from fast food) had 23.8% (95% CI: 11.9%, 36.9%) and 39.0% (95% CI: 21.9%, 58.5%) higher levels of ΣDEHPm and DiNPm, respectively, than nonconsumers.”
[105] “In our study we observed a positive association between ultra-processed food and urinary concentration of most phthalates and bisphenol, suggesting that contamination by contact materials may be an additional pathway to explain the associations seen between ultra-processed food and various health outcomes…” “In this cross-sectional study of the US population aged 6 + years, there was evidence of monotonic dose-response association between ultra-processed food consumption (expressed as % of total energy intake) and urinary concentration of ΣDiNP, mCNP, mCPP, mBzP and BPF. No association was observed with ΣDEHP, BPA and an inverse association was observed with BPS. The association with BPA gained significance when ultra-processed food was expressed as % of total gram intake.”
[106] “In adjusted models, higher energy from ultra-processed food was associated with higher urinary concentrations of MCPP, MCNP, and MCOP but not MBzP, ∑DEHP, or bisphenols. … Ultra-processed sandwiches/hamburgers, French fries/other potato products, and ice cream/pops were associated with higher concentrations of multiple chemicals.”
[107] “Ultra-processed food consumption was associated with increased concentrations of urinary MEP. Conversely, consuming unprocessed food was associated with lower concentrations of MEP and MBP in the Asian Taiwanese adult population.” [monoethyl phthalate (MEP); monobutyl phthalate (MBP)]
[108] “Seafood samples packed in polypropylene (PP), polyvinyl chloride (PVC), tin can, and glass containers were monitored for 4 months to determine the time-dependent migration of phthalate esters (DEHP, DBP, BBP, DINP, DIDP, and DNOP). DEHP was the most phthalate esters found in food samples…Unfortunately, all three packaging materials have an active role in the migration of phthalate esters into foodstuff.”
[109] “Because they are not chemically-bound, phthalates and bisphenols used in food contact materials or food processing plastics can transfer to food (Koch and Calafat, 2009).”
[110] “Packaging accounts for ~40% of all plastics produced since the 1950s, of which 41% is used specifically for food or beverages (Schweitzer et al., 2018). This statistic refers primarily to the latter stage of the food system in which food products are processed, marketed and transferred to consumers. However, plastics are also used extensively at other stages of the food system, for example in agricultural mulch, fishing nets and crates for transporting produce.”
[111] “BBP [butyl benzyl phthalate] is used in the manufacture of vinyl tile and PVC to make food conveyor belts, carpet tile, tarps, weather stripping, and, to a limited extent, vinyl gloves and adhesives. BBP can be released into the environment during production, incorporation into products, use, and disposal.
The best estimate of exposure to the general public is 2 µg/kg bw/day from food in adults…”
BBP as endocrine disruptor https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2872021/
[112] Table 1: storage containers used in industrial food production
[113] “Tsumura and others (2001b) investigated phthalate contamination of retail-packed lunches caused by PVC gloves used in the preparation of foods. The PVC gloves used in the preparation of the foods contained up to 41.0% of DEHP, 60.2% of DEHA, 74.8% of DiNP, and 27.9% of BBzP. Higher levels of phthalates were found in general in the final food products (contacted withPVC gloves) than in the uncooked (not yet contacted with PVC gloves).”
[114]https://www.nytimes.com/2017/07/12/well/eat/the-chemicals-in-your-mac-and-cheese.html?partner=slack&smid=sl-share
[116] https://www.kleanupkraft.org/data-summary.pdf see table 1— depends if you look at the chemicals in the fat or the chemicals in the product generally: “Table 1 shows that the average total concentration of phthalates in macaroni and cheese powder was more than four times higher than in natural cheese, on a fat basis. (“Natural cheese” is an industry term meaning not processed or imitation). … After adjusting for percent fat content, cheese powder and processed cheese still had two times higher average fresh-weight phthalates concentration.”
[117] Sheela’s study: https://pubmed.ncbi.nlm.nih.gov/23443238/
[118] “To evaluate the contribution of food packaging to exposure, we measured urinary BPA and phthalate metabolites before, during, and after a "fresh foods" dietary intervention….Urine levels of BPA and DEHP metabolites decreased significantly during the fresh foods intervention”
[119] “PVC tubing is commonly used in the milking process and in the bulk transfer of milk between tankers and storage tanks in dairy farms and dairy processing plants. Like many other PVC products, plasticizers such as phthalates are used in PVC tubing to make it more flexible, and among which DEHP is the most frequently used with as much as 40% in the tubing (Ruuska and others 1987; Tsumura and others 2002a). Since they are not chemically bonded to the polymer, plasticizers can migrate from the PVC tubing into milk, especially at relatively higher temperature during the milking process.”
[120] “The majority of Americans have detectable urinary concentrations of multiple phthalate metabolites and bisphenols (Centers for Disease Control and Prevention, 2018). While these chemicals are rapidly eliminated via urinary excretion (Calafat et al., 2015), the omnipresence of exposure sources is of growing concern given that exposure to some phthalates and bisphenol A are associated with wide-ranging adverse health outcomes related to their ability to disrupt the endocrine system (Gore et al., 2015).”
[121] “Urinary metabolites of DEHP and DiNP are detected in 98% of the US general population (Zota et al. 2014) with higher exposures observed in children (Koch et al. 2004; Wittassek et al. 2011). Urinary metabolites of BPA are detected in 90% of the U.S. population with higher exposures observed in non-Hispanic Blacks, children, females, and those of lower socioeconomic status (Calafat et al. 2008; Nelson et al. 2012).” [di(2-ethylhexyl) phthalate (DEHP); diisononyl phthalate (DiNP)]
