Podcast Episode 78 Transcript – Lectins

Aidan Muir:

Hello and welcome to the Ideal Nutrition Podcast. This is episode 78. My name is Aidan Muir and I’m here with my co-host Leah Higl. And today we are talking all about lectins. And I suppose looking at it from the perspective of what are they, why should they matter? If they matter, how much should we care about them and what should we do about them? This is a topic that I probably don’t see as much as Leah does see, I feel like it’s a little bit more relevant in her space. And because of that and also because Leah’s got a blog post on this that’s very helpful as well – We’re going to be looking at it through the lens of me interviewing Leah. I’ve obviously done a bit of reading, done some research and everything like that, but I still think it’d be more helpful if we do it in that format. So starting with the basics, what are lectins?

Leah Higl:

So lectins are a type of protein that are found in a range of foods. They’re basically grouped together based on the fact that they are proteins that bind to carbohydrates. And this feature is usually, people talk about it in plants in terms of a protection mechanism in plants, because basically what this does is makes them resistant to digestion and they’re not very… They are very stable in an acidic environment. So the human stomach, obviously quite an acidic environment and that’s usually to facilitate the breakdown of different foods. But lectins are particularly resistant to being broken down because of this function that they have with binding to carbohydrates.

Aidan Muir:

What are they in?

Leah Higl:

They’re in a fair bit. Plant foods predominantly, so we’re mainly looking at legumes, soy foods, greens, all different kinds of vegetables, but particularly nightshades, some nuts including things like cashews and peanuts. Also, in a lot of seeds, it’s different fruits. So I’m just naming a lot of plant foods right now cause that’s predominantly what they’re in.

I think it’s interesting to note that gluten found in wheat products is also technically considered a lectin. And lectins are also found in some non plant-based foods being some dairy products. Like A1 protein is a lectin like protein, can be found in eggs in small quantities and meat from animals that have been fed corn and soy as well.

Aidan Muir:

And lectins are like, they’re a variety of things. It’s like a group of things. So-

Leah Higl:

It’s a group of things. So there’s all different kinds of lectins and there are different ones that have different functions and are in different foods. They’re just pretty much grouped together based on the fact they’re proteins that bind to carbohydrates and that covers a ton of different things.

Aidan Muir:

Yeah, cool. Did you see the case study kind of thing on red kidney beans? I think it was uncooked red kidney beans and a group of people, they get hospitalized or they’ve got like, yeah, vomiting, diarrhea, those kind of things. And somebody claimed to have only eaten four of them.

Leah Higl:

Only four? Okay. I didn’t see that.

Aidan Muir:

I think they were soaked but they were uncooked.

Leah Higl:

Yeah. So the lectins in uncooked red kidney beans are considered poisonous to humans and can have the effect of diarrhea, vomiting. Your body just wants to get rid of them. But during the soaking and cooking process, they are broken down. So it’s actually not an issue when it comes to cooked red kidney beans. So just don’t eat uncooked red kidney beans and you’ll be okay.

Aidan Muir:

I also like that cause it comes at it from that, I suppose that nuanced perspective of being, these things do exist and are relevant and it’s worth having some awareness of them.

Leah Higl:

Definitely they’re a thing and there are times where they can be quite harmful to our health. It’s just usually in circumstances that you wouldn’t typically eat them. We’re not going to have a lot of uncooked legumes in our diet. And a lot of the time processes like cooking, soaking, sprouting, that’s actually going to reduce the lectin content of things quite dramatically and therefore it doesn’t really… That’s how we usually eat them, so it doesn’t matter.

Aidan Muir:

Yeah, cool. And I guess looking at it from that perspective of why are people proposing that we should be avoiding lectins?

Leah Higl:

So there’s quite a few different reasons. I think the first thing to start off with is there’s pretty much this one guy that’s really anti lectin and his name is Dr. Gundry and he wrote a book called The Plant Paradox. And a lot of the different reasons why people started avoiding lectins, or at least why it got popular comes from this book. So a few reasons that he notes is A, some lectins are actually poisonous or toxic to humans. So things like the lectins in red kidney beans when they’re uncooked. So that is a real thing, but not all lectins are like that. So that’s also important to note. The second reason that is probably the most cited reason for removing lectins from someone’s diet is that you quote unquote can’t digest them. So they are resistant to digestion in the gastrointestinal tract, but that doesn’t necessarily make them bad either.

There are a lot of things in our diet which are non-digestible or hard to digest. So things like dietary fiber, things like FODMAPs that are really great for you and really great for gut health overall, but yeah, technically you can’t digest them. But that is one of the reasons that is heavily cited for not eating lectins.

Aidan Muir:

Yeah, cool. And I’m pretty anti going after one person or anything like that. It’s part of a philosophy I’ve developed over the years, but when you Google lectins, it is just Dr. Gundry coming up everywhere, videos, everything like that.

Leah Higl:

He’s definitely the most popular person. I think he is the one that popularized it with the book, the Plant Paradox. And there are a lot of celebrities and stuff that jumped on his bandwagon, and kind of held him up as this person that knew this amazing thing that no one else did. So that’s the only reason I mentioned because if you Google it, he’s the only one that comes up. So I think it’s worth mentioning that that’s kind of where this is coming from.

Aidan Muir:

Yeah. A hundred percent. And even though it is all mostly popularized by one person, I still do see these questions just coming from the average person and it’s almost like, and I don’t think Chinese whispers is the right word, but it’s almost like it’s come from here and it’s kind of been passed along to a few people and then it is not an uncommon question being like say people start looking into plant-based diets, they hear about lectins and how we should be avoiding them or whatever. And then it becomes confusing.

Leah Higl:

Yeah. And I think the hard part is that we’ve said it comes from a grain of truth in terms of not all of this is false. There are reasons why you would avoid certain lectins like AKA in red kidney beans, et cetera. Or there are reasons why lectins, I guess, can have a negative impact on certain things. We might talk about nutrient absorption soon. So it comes from this grain of truth and then it’s just been taken way too far.

Aidan Muir:

So lectins can reduce nutrient absorption of stuff like iron, zinc, and calcium. How relevant is that?

Leah Higl:

Honestly, I feel like it is barely relevant at all because I think if we look at plant-based foods, there are a lot of things that we call antinutrients in plant-based foods. So even things like oxalates and phytates, and all these other things in plant-based foods that do reduce the absorption of things like iron, zinc, calcium, other nutrients. But it doesn’t make those foods bad for you. It just usually means that if you are getting a lot of these nutrients from these plant-based foods that contain these antinutrients, whether it’s lectins or things like phytates and oxalates, you probably just need to increase your overall intake of those particular foods and get a little bit more in.

Aidan Muir:

Yeah, yeah, a hundred percent. Another area where it’s relevant, anti-nutrients matter, but there’s also ways.

Leah Higl:

But the solution isn’t avoiding the antinutrients, it’s just having more of the nutrients to kind of combat that limited absorption from the lectins. So because a lectin free diet is kind of almost heading more towards the carnivore spectrum where you are cutting out, there’s a ton of really awesome foods. So overall you’re decreasing usually the quality of your diet in order to avoid these antinutrients. So it just doesn’t make much sense to me.

Aidan Muir:

Yeah. And I suppose jumping on that bandwagon, one of my first thoughts whenever overly simplistically assessing certain claims about dietary approaches and stuff like that is we do see research on plant-based diets, and longevity showing on average people who follow plant-based diet live longer. From memory there are studies on vegan diet showing 10 years longer than the average. Which is quite significant. And I, amongst other people can point at a lot of flaws in that like healthy user bias and stuff like that. But one of the things that I think is super, super relevant is if we look at it through the lens of how some people are proposing this, as in lectins are toxins that build up in your body over time and these anti-nutrients that cause all of these issues, they’re specifically being linked to autoimmune conditions, and stuff like that as well. How is this 10 years extra lifespan also occurring as well?

Leah Higl:

It’s like those two things just can’t simultaneously be factual, right. A lot of people, particularly Dr. Gundry and people that follow his teachings kind of say that lectins do cause things like weight gain and gastrointestinal disorders, and yeah like you were saying, allergies and a different kind of autoimmune disorders. But we know that people that eat a ton of these plant-based foods overall tend to be pretty healthy or healthier than people that avoid them or have very little plant diversity.

Aidan Muir:

Yeah. And specifically on the legumes topic, there’s these areas called the Blue Zones, people can poke holes in this but you can poke holes in everything. But there’s areas called the Blue Zones, they’re three times more likely than Australians to live to a hundred years old. And almost every single one of them, these populations have high intakes of legumes specifically. It is hard to argue at a population level that our health concerns are being brought upon by too much legumes.

When we can look at that and then also being in Australia, do we consume many legumes to start off with? If we look at it also from the fruit and vegetable intake, this is a commonly claimed or a commonly cited kind of stat, but it’s like if we look at just the recommended daily intake of fruits and vegetables in Australia, 6% of people do that, reach that target. It’s hard to be like, “These are the issues.”

Leah Higl:

Yeah. The reason we’re all sick is because we’re eating way too many fruits and vegetables, and legumes and nuts and seeds. Yeah, that doesn’t check out.

Aidan Muir:

I don’t know. So I know that’s overly simplistic, but it is something to factor in amongst everything else we’re saying here as well.

Jumping on the weight loss kind of thing as well because that is a common claim, going lectin free, that causes weight loss. One I guess we can address from the calories perspective, you can also share your thoughts as to why you think this is anecdotally happening.

Leah Higl:

I honestly think it comes down to if you are going from a diet where you’re really not thinking about what you’re eating and then you’re overall changing it up to a more whole food based diet, you’re putting more effort into your nutrition, I think there’s a chance that your calorie intake’s probably going to decrease. And that’s probably going to have an impact on weight loss, weight management long-term. But when we look at… There is no actual evidence to suggest that going lectin-free or low lectin is going to improve fat loss or weight loss outcomes. So it really does just come from this anecdotal evidence where I think it’s just people eating less calories because they’ve made these changes to their diet and they’ve lost weight because of that.

Aidan Muir:

Are there any studies at all? As a genuine question, are there any studies at all on a lectin-free diet directly?

Leah Higl:

Not that I am aware of currently. Especially not looking at weight loss or weight management. I think-

Aidan Muir:

Even for other areas like autoimmune conditions and stuff like that.

Leah Higl:

Even just other things, it’s slim to none. Yeah, there’s nothing, obviously you can extrapolate some research kind of looking at specific foods that are high in lectins, your legume based foods and try to extrapolate that to outcomes with lectins. But there’s nothing specific. No.

Aidan Muir:

Cool. Sharing my own thoughts on a lot of… Because yeah, off air we were speaking about how he goes through the comments of the YouTube videos of people talking about low lectin diets and stuff like that, and a lot of the comments are supportive. One of the questions I genuinely actually do wonder is, does Dr. Gundry have people commenting on his videos? Does he have stuff? I’m not actually accusing that, but it seems like it’s all positive comments and stuff like that. It’s like, are negative ones deleted? I actually don’t know. But regardless, I do think there is genuine positive comments in there and a lot of people who are experiencing these benefits and stuff like that. And looking at it through the lens of being like, okay, let’s say there are a lot of people experiencing these benefits. Why do I think that is happening?

The weight loss one is simple. If you have to make a dramatic dietary change, oftentimes it results in a calorie deficit. I’ve seen him talk and say things like, “I think we should eat the way we used to eat 10,000 years ago.” And it’s like if you do that, you do have a minimally processed diet, you probably end up consuming fewer calories. That’s not necessarily surprising. With certain autoimmune conditions and stuff like that as well, it’s like well there is a dramatic change in your diet. Once again, some of those dramatic changes can also coincide with things that may or may not improve your autoimmune condition as well. Gastrointestinal stuff, lectins can be difficult to digest.

They can also overlap with a lot of high FODMAP foods as well. They can overlap with other food chemicals as well, such as salicylates too. Once again, making this change might cause those results even though it’s not necessarily only due to lectins or even largely due to the lectins.

Leah Higl:

It could be part of the puzzle.

Aidan Muir:

Yeah, it Could be part of the puzzle for sure. And then I’ve seen other people commenting about, I used to have eczema. Now I don’t. I’ve spoken previously about salicylates and eczema, how there is a bit of… There’s not masses of research on this, but if I was interpreting the research, it seems based on the research we’ve got somewhere between about 60 to 80% of people who have eczema. If they went low salicylate would notice improvement. If you cut out lectins, you would also be cutting out salicylates. So I suppose I say that because it’s from personal experience, there are people who try a low lectin diet and notice benefit, and then hear us talking and be like, “Nah, this is ridiculous.”

Don’t knock it’s true until you try it. But I’m like, there is a lot of potential factors going into why there is these positive benefits for a lot of people as well.

Leah Higl:

Yeah, there’s so much overlap with other things. Like the food chemicals, FODMAPs, general dietary changes that could be… I think your anecdotal evidence is not, shouldn’t be the be all and end all because there is so much overlap with other things.

Aidan Muir:

And while we’ve spoken about how there could be indirectly benefits to lectins through other components of foods and stuff like that, being like plant-based diets consistently linked with health outcomes and stuff like that. Are there any benefits to lectins themselves directly?

Leah Higl:

So there’s a few things that I like to hit on when people ask me that. And the first one is lectins do potentially have a number of health benefits in themselves. So some lectins do act as antioxidants to protect the body’s cells from damage. So we know antioxidants are usually a helpful thing to have in your diet and some lectins act that way in the body. Secondary to that, they also slow digestion and absorption of carbohydrates, which can have you staying fuller for longer and prevent sharp increases in blood glucose levels. If that’s something from a health perspective that is beneficial to you. So that’s a factor as well. There is some research in lectins as anti-cancer treatments, but I’m not jumping on that bandwagon anytime soon after looking at the very, very kind of slim pickings of research that there is.

But hey, early days potentially. Again, diets that are rich in plant-based foods potentially have those better health outcomes overall. So maybe in relation to cancer as well. And this may play a role. And there is also a wide array of research showing that these lectin containing foods that we’ve spoken about in terms of legumes, whole grains, nuts, seeds, they have been associated with lower rates of type two diabetes, cardiovascular disease, and generally beneficial in maintaining healthy weight. So whilst it may not be due to lectins, these foods, we know they have good health outcomes overall and a lot of these foods they’re a great source of different vitamins, and minerals and contribute to an overall good quality diet.

Aidan Muir:

Cool. So I guess summarizing in a way that we’ve already kind of summarized, but I like summarizing anyway. If somebody was thinking about consuming more of these lectin containing foods, how much should they care about lectins? Should they do anything about it beyond the red kidney beans or just kidney beans, like cooking them. Beyond that aspect, is there anything you think people should do with this?

Leah Higl:

Yeah, I think talking about lectins is almost for the general person over complicating something that doesn’t need to be complicated. I think if you have trouble digesting some of these foods, sometimes extra soaking, sprouting, cooking could be beneficial from the reduction of lectin content, but also its impact on FODMAP content even of different foods, et cetera. But overall, I would say don’t worry about lectins and just try to include these foods pretty regularly because they’re pretty awesome.

Aidan Muir:

Awesome. Sounds good. Well, this has been episode 78 of the Ideal Nutrition Podcast. As always, if you could please leave a rating and review if you haven’t already, that would be massively appreciated. But thank you for tuning in.