The Plant Paradox by Stephen R. Gundry, MD: A Review - or Are Lectins Really Bad For You?
To gain benefit from this review, you DO NOT need to have read the book, The Plant Paradox by Stephen R. Gundry, MD as I will explain his argument in brief in this article.
Book Premise
You may have heard of Stephen R. Gundry, MD, particularly if you're at all into listening to podcasts. He's been on many in the last few months, mostly because he was on the now-typical 'media drive' for the launch of his latest book, "The Plant Paradox: The Hidden Dangers in "Healthy" Foods That Cause Disease and Weight Gain". All of the leaders within the health community interviewed Dr Gundry, and he made a powerful (and actually very measured) argument about his book premise during each conversation.
The Plant Paradox explains the science behind his previous work, "Dr Gundry's Diet Evolution" and gives a compelling explanation about the nutritional conclusions he has come to in his work as a doctor.
Dr Gundry is a renowned cardiologist - and a cardiothoracic surgeon. He earned his medical stripes long before he stepped into a more 'alternative' health movement (by which, I mean preventative health, i.e. healthcare which prevents people ending up needing heart surgery). It was from the coalface of operating on seriously ill patients that he had an almost satori moment, understanding that the surgery for heart disease was lifesaving and powerful - but it wasn't addressing the issue of why patients wound up on his operating table to begin with.
This story is similar to the beginning of so many within the Integrative Medicine space. We all appreciate the miracle of modern medicine, but we also recognise that there is an issue with how many patients end up requiring such acute healthcare. This is why we come to lifestyle and dietary medicine: these are the interventions that can be made as investments in wellness before patients are sick enough to need the operating theatre.
This appears to be the journey of Dr Gundry - and his 'wake up' sparked the end of his operating career and the beginning of his promotion of dietary measures to alter the health prospects of individuals - long before they would have got to the point of needing to go under his own knife.
I appreciate Dr Gundry because, given his background, he gains credibility from the medical community. I have had several medical professionals who previously would not have entertained a dialogue with me about nutritional medicine actually start a conversation about food based on their reading of Gundry's work. This, believe me, is progress.
But what of the specifics of Gundry's writing, what is his argument about the current nutritional landscape and the modern disease epidemic?
The book outlines the science behind his concept that the proteins in plants called Lectins are responsible for much of modern disease.
These Lectin proteins are found in countless foods: everything from grains (including the much-maligned gluten) and seeds, to the skins, rinds and leaves of numerous fruits, vegetables, nuts, beans and dairy products. He explains, in impressive detail, how damaging and inflammatory Lectins can be to the human body - and the myriad of health effects that come as a result.
His work is overwhelming, I have to say. Even working in nutrition and knowing all about Lectins prior to reading this book (they were a vital part of my understanding of my own issues approximately 6 years ago) I was worn out by reading the 360+ page book.
Lectins are literally everywhere. They are carbohydrate-binding proteins. If you have read my All About Gluten page on the Paleo In The UK website then you will understand about Lectins. Gluten is a protein which contains Lectins - in fact, it's part of the reason Gluten is challenging for many individuals. Here I will keep my explanations of the science of Lectins quite basic, because for the full story I really would recommend reading both my article and Stephen Gundry's book. However, Lectins are part of the plant's defence mechanisms. They are compounds (proteins) which bind to the carbohydrates, especially complex ones (known as polysaccharides), in plants. They are sort of sticky and because of their ability to both make plants indigestible AND stick almost indiscriminately to carbohydrates they are thought to be able to bind to sugars in the human gut, the cells lining the human digestive tract - or indeed the digestive tract of any animals who eat the plants.
Having said the above, there's not really a clear 'why' for the presence of Lectins in plants. We can hypothesise (and Dr Gundry does) that it's to do with the plant making itself indigestible so that e.g. plant skins and seeds will pass through digestive systems without being broken down, thereby re-distributing the plant's seeds allowing it to proliferate. But according to Dr Gundry, Lectins are "designedto disrupt cellular communication by, among other things, causing gaps in the intestinal wall barrier, a condition known as leaky gut."
Now I've looked at the literature... and there's literally NO evidence to suggest that plant Lectins are 'designed' to do anything that we can be sure about. There is some interesting evidence to suggest that plants produce MORE Lectins (and some other toxic/damaging compounds such as phytates) when under threat. This has been tested by having an animal chew one side of a plant and then testing the chemical constituents in the other side. So yes, this would seems to confirm that plant Lectins are part of a stress response, or a protective response of the plant. But there is no 'intent' behind this mechanism. It's a bit like the Cell Danger Response of humans - every living thing appears to release more stress-based molecules when under threat. The way you read Gundry's text, you would be forgiven for thinking that plants were sentient and purposely produce poisons to attack humans...
Moreover, the fact that Lectins are in most living things is of interest - because that includes humans. We use Lectins in our immune systems as complement proteins (these bind antigens for targeting by the innate immune system prior to acquired immunity being developed). We also have receptors which are made up of Lectin proteins... because, as I have said, they bind stuff. That makes them good in situations where stuff needs to stick. Surely if all Lectins (as Gundry suggests) are terrible then we'd all be pretty much dead by now?
Well no, let me be a bit more measured. Dr Gundry is careful to go through his argument and separate the toxic Lectins from the less-toxic ones (mostly), though he does stop short of really illuminating the reader about the ubiquity, utility and potential benign nature of some Lectins as a protein. Because to do so would dilute his argument.
His main point is simple... plants contain protective mechanisms which are, by their very nature, toxic to those that consume them. The mechanism of action of these toxic proteins known as Lectins is enough to cause mass dysregulation - everything from interrupting nerve signalling to creating intestinal permeability through their activity in the cell wall. Furthermore, through the contribution to both inflammation and systemic hormonal dysruption, Lectins (in particular the toxic Wheat Germ Agglutinin) can contribute to weight gain, metabolic damage, diabetes and both heart and kidney disease. They can interrupt hormonal signalling, cell signalling, nervous system communication and result in everything from gut distress to dementia.
Wow…
The book does make distinctions between the Lectins in wheat and the slightly-less-toxic-but-still-potentially-triggering Lectins within most other grains (especially brown rice... please use white instead), the skins of vegetables (please peel and de-seed, especially with tomatoes and peppers) and non-ripe fruits (please buy fruits and veggies in season). It then launches into a Plant Paradox Program which is designed to eliminate the Lectins from your life, but in reality probably just reduces the toxic Lectin load quite considerably. And of course, there's the ever-present recipes, tables of ingredients, lists of 'foods to include' and justifications for a) A Three-Day "Cleanse", b) Ketogenic Diets using the Plant Paradox Program and c) using this approach for healing kidney disease (preventing dialysis), beating cancer (focusing solely on the Warburg principle... something I will cover in future blogs) and halting the progression of Alzheimer's.
Phew... this seems to be pretty miraculous.
But I'll be honest, guys. I'm reviewing a book that I could barely read. I could barely read it because the writing - the way the arguments are expressed and the conviction and language used - made me feel a little bit nauseous...
How To Sell Any Health Approach
Want to write a bestselling book about a nutritional approach? Well there are three things that you need to make sure that you do. All three of these were achieved most successfully in just the introduction to Dr Gundry's book:
Relieve guilt - you have to insist that the health conditions that people are facing are NOT THEIR FAULT: most importantly obesity and diabetes which are often thought of as conditions of behaviour/choice rather than true 'illnesses' or 'diseases'
If something is not anyone's fault, you have to FIND SOMETHING ELSE TO BLAME. Seems at the moment it can be anything - from evolutionary biology to carbs, fats, even protein now (heard of protein fasts, anyone?!), to sugar (always sugar), to transfats, GMO's, non-organic foods, glyphosate... and now LECTINS!
Offer an easy solution, typically removing the above substance that you chose to paint as an 'enemy'... oh - and promise that your way is that easy solution and the recipes/books/diet choices you recommend will literally cure everyone, of everything
Then there's a fourth requirement to the above process... You have to be able to write a compelling book about your chosen enemy and your promised cure which throws around the phrases "everything you thought you knew about your diet, your health, and your weight is wrong.', "your health problems are not your fault", "the secrets I share with you will reveal what is keeping you sick, tired, depleted of energy, overweight (or underweight), fuzzy headed, or in pain" and - most damningly - "the real cause (for your current ailments) is so well hidden that you would never have noticed it", followed by the depiction of the selected 'enemy food' (in Gundry's case this really niche, ubiquitous plant molecule, the Lectin) as the 'secret' health disruptor, 'the real cause' of illness - and the program the book is selling must be promoted as your 'miracle cure'.
And yes, that's all in the opening paragraphs.
How, Why - and WHY NOT - To Sell Something As An Enemy
It is this energetic - the 'you have been lied to, let me tell you the truth' - that permeates SO MANY nutritional programs, books, protocols, regimens and dogmas. The reason this is what is used to sell these approaches is because it works. If you can convince people that they are not to blame - and moreover, that there's a relatively simple solution - then it is attractive and it's basically nutritional click-bait.
But bodies are phenomenally complex. I lived for about 17 years feeling crazily insecure about mine but never really doing anything about it. Then my health took a nosedive and I was plunged into this nutritional landscape wherein all I wanted was to change the way my body felt. I highlighted on so many of these 'this food is the enemy' protocols in my time - everything from Lectins, to oxalates, salicylates, histamine, FODMAPs, gluten, animal protein, fats, fruits, sugars, fibre... you name it, I've been in the space where I've avoided it because somebody promised me it would make all of my problems go away.
In my profession we are often accused of selling snake-oil, and this whole approach (the 'miracle cure, avoid this' approach) is why
Unfortunately, healthcare is business. In conventional medicine this has a direct influence that is oft-reported: Big Pharma influencing prescription prevalence and the postcode lottery of some medications, operations and treatments. But this financial bias is also present in Functional Medicine, where insurance does not cover our services and we aren't on the staff of a hospital so we're mostly self-employed and we're often recovered patients or professionals who've fallen out of love with the existing healthcare model.
Because our services stem from this root, it is common for there to be just as much bias in the integrative landscape as there is the conventional one. The difference is that instead of being faithful to certain medications we will pin our allegiance to a dietary style - and if we can write a book, program, ebook or interactive web-course to sell said dietary style (promising miraculous results) then we gain passive income, we influence a lot of people and, voila!, you have made a name for yourself.
The reality of this is that the market of healthcare requires us all to be businesses - and the sexy cures sell.
The problem is that no-one, in my opinion, is actually selling snake-oil, and whilst I can't speak for conventional medicine, I actually don't think that many in the Functional or Integrative worlds are intending to be disingenuous. To bring us back to this very specific example of Dr Gundry - he is 100% correct in his assertions about certain plant proteins. And he is also a practitioner who has witnessed his approach help himself and many of his patients. The science - the mechanism - is fairly factual...
What isn't accurate is the emotive context and the aggressive terminology he uses. It isn't appropriate to sell avoiding Lectins as a cure for everything from cancer to Alzheimer's. It isn't fair to label Lectins responsible for every ill. And it isn't OK to use such compelling language, backed with some convincing, authoritative-sounding factoids from a medical professional, to sell a concept that removes a lot of foods from people's diet, purporting that those foods were responsible for their illness.
So Is There Anything to the Plant Paradox Theory - Is Gundry Right?
The difficulty in nutrition studies, or rather one of the difficulties, is that there is a difference between mechanistic data and in-clinic, observational, what-actually-happens-in-the-real-world information. That's not to say that the two never correlate - because they often do. But often does not mean always.
Let me explain... the basic tenet of the anti-Lectin doctrine is that plant protection mechanisms such as Lectins are ever-so-slightly inflammatory to the human digestive system. They can also interfere with things like intestinal permeability, nerve signalling (not so sure we've proved this one yet, but I'll include it) and also the microbiome. Lectins are on the skins and seeds, the outer shells and husks - it's like the walls of these plants contain these proteins which irritate our gut lining and create challenges to intestinal wellbeing and systemic health.
Now, mechanistically there is a great point to this argument. It has been shown that these specific plant proteins can wreak havoc - by which we mean that we've tested people and found these proteins systemically throughout the body. Wheat Germ Agglutinin (WGA) has been found in the walls of blood and lymphatic vessels, suggesting that these proteins not only CAN translocate across the gut barrier, they end up in systemic circulation and can modulate the immune response.
Additionally, tomato saponins (another plant defence mechanism) are also known to translocate, i.e. leave the confines of the gut. Anything that escapes the GI tract becomes an immune target, so the argument goes, because it comes directly into contact with the Gut Associated Lymphoid Tissue (GALT) which is where our immune system 'learns' what might be threatening. This can contribute to immune system dysregulation, inflammation, interruptions in cell signalling and/or hormonal regulation... basically the results can be catastrophic (the aforementioned cancers, neurodegenerative conditions, nervous system issues and, of course, weight gain).
The problem that I have with all of this is that there are several major, important factors that must be considered. Whilst all of this may be true mechanistically, a lot of these studies are done in animals. This is absolutely fine, this is where all science must start because animal models are good equivalents to the human body, especially intestinally.
However, when we are looking at the relatively complex workings of the human body, focusing on the mechanistic effects of certain so-called 'anti-nutrients' in the diet negates to recognise that the human body has evolved to face - and thrive in the face of - constant immune challenges... in ways that perhaps our animal equivalents (like the rats/mice used in such studies) have not.
Our human bodies are built to withstand the presence of antigens and 'invading' proteins/microbes. Our bodies are used to things interrupting our cell signalling, affecting our nervous system and having to deal with intruders that are challenging to our biology. We are not supposed to, in my humble opinion, operate in a vacuum where we wrap ourselves in cotton wool and avoid everything that might possibly present a threat to our bodies. We've survived for thousands of years by evolving in response to threats. If plant compounds are slightly irritating to our digestive systems, I imagine this is why we've evolved alongside the bacteria that live within us - because where we fail, they can succeed, breaking down more fibres and proteins than we innately can and minimising their impact on the human body.
So I'm not saying Gundry is wrong. His mechanistic data is impressive, and true. And yet it neglects to acknowledge that we have been consuming Lectin-containing foods for centuries - though he does cover this. I think his argument is "yes, and we've been getting progressively worse the more Lectins we include in our diet". But the truth is that, unlike other animals, humans are one of the more powerful and omnipresent animal species on the planet.
This would suggest that whilst animal intestines may be seriously affected by some of these anti-nutrient containing plants with their Lectin defence mechanisms... perhaps the human digestive tract and the immune system which has evolved to accompany it (not to mention the microbiome that has evolved to live inside it) might be absolutely fine when consuming these apparent 'toxic' proteins.
Moreover, mechanism is one thing. It is important, too, because nutritional studies are complex and tricky to design in ways which are at all reflective of real life. But the mechanism of translocation which we can clearly see occurring does not - yet - correlate well to the data of poorer health outcomes. In fact, the Lectins can do 'damage' by binding to the epithelial cells of the GI tract and yet we know, especially with the saponin Lectin of the tomato mentioned above, that the human digestive system heals this 'damage' relatively quickly. Even with Gluten, we know that some individuals really struggle with this but there are others for whom the interaction with their GI tract is experienced and then recovered from almost immediately.
This said, every single day in my practice I witness individuals who have noticed distinct, discernible improvements in their health conditions (everything from brain fog to arthritis, headaches to digestive disruption, menstrual cramps to mood disturbance, fatigue to poor temperature regulation, to weight and/or water retention) when they cut Lectin-containing foods out of their diet. I am not just talking about Gluten - because many of these clients have been gluten- and dairy- free for a long time prior to this last step of eliminating the foods which are high in Lectins. For many, it seems like eliminating Lectins really is the 'miracle' in their health journey.
Now, this is the evidence that I have to look at - along with all the research papers. I have to assess the fact that my patients get better when paying attention to these Lectins, which 'science' would suggest have little adverse health outcomes, despite clear ability to translocate across the gut barrier and disturb cellular function. There is perhaps no good research to suggest that Lectins alter health outcomes... but that does not mean that there is a lack of evidence - because I see people get better when removing Lectins, and that's evidence. And yes, the plural of anecdote is not data... but sometimes in the battle for scientific relevancy we lose the fact that sometimes we don't know the exact why - but knowing it happens means that we, as clinicians and not researchers, cannot ignore what stares us in the face. Science has (often) been wrong. Faced with a patient who feels a much lower inflammatory burden when eliminating anti-nutrients, I'm tempted to state that lower inflammation is almost ALWAYS the better health space to occupy, irrespective of the evidence to tie Lectins to chronic disease states... If Lectins can cause inflammation - I'm tempted to eliminate them from my clients' lives.
But What Is Actually Going On With Lectins?
So, this whole article might thus far seem contradictory: I'm appalled by the rhetoric in Gundry's work and yet I do see the value in lower-Lectin diets for some of my patients. What on earth is my rationale then?
Well, quite simply, the Lectins' ability to create gastrointestinal permeability and/or systemically alter metabolism and cell signalling is important, and yet most human beings are utterly fine with this impact which is, ultimately, relatively weak and makes little-to-no difference to their health status overall.
Then there are those (my patient population, for example) whose health is threatened and challenged already: perhaps with an autoimmune condition or a gut bacterial imbalance, possibly with gut permeability or with a complex hormonal issue or metabolic dsyregulation. For these individuals, the inclusion of Lectins may be like adding fuel to an already raging fire, in which the Lectins are the kindling which will keep that fire of inflammation alight.
Can kindling alone produce a roaring fire? No. You need matches and bigger logs and oxygen. Such is true with Lectins: it is highly unlikely that Lectins are the root cause of anyone's health issues (save for the gluten in those with coeliac disease). There is no way that in a perfectly healthy individual the consumption of a tomato and a few nuts is going to cause mass dysregulation. To be fair to Gundry, I don't think he's saying this either. However, the way his argument is presented has you believing that every human should be wary of the Lectin content of all foods, however small.
It is simply too didactic to state that Lectins are universally bad - and all Lectins are bad for all people. As with all food - the Lectins really aren't the problem, the digestive system and the human body into which these Lectin-containing foods are being fed is. Lectins can be damaging to some people, but that's more of a reflection of their current health status than a reflection on the innate toxicity of Lectins.
The other thing to recognise is that Lectins aren't just one thing. In my article about Gluten on the Paleo In The UK site I have made the distinction between Lectins and toxic Lectins - suggesting that the WGA-type Lectin is capable of causing much more dysregulation than the saponin on a tomato, and clearly less dysregulation than the endogenous Lectins which literally help us develop our immune systems. It's simply not fair to categorise all Lectins in the same category. Doing so means that you eliminate most of the plant kingdom.
Being fair to Gundry again, he does state throughout his book that he is not anti-plants. He presents alternative ways to eat plants (mostly cutting/washing off the lectin-containing parts) and does suggest that cooking can denature some of the less potent Lectin content of foods. My issue, however, is that he states in other paragraphs that "Lectins can savagely damage the absorptive layer of your intestines... Think of Lectins as incoming bombs. In order to repair the damage, you must stop eating lectins - and I am going to show you how." (Page 86). This is extreme... and it just gives entirely the wrong impression to the reader about who actually does need to be cautious about Lectins and how broad and impactful their effects actually are.
Is There A Middle Ground?
I think that sometimes my fellow practitioners are allergic to the Middle Ground. And unfortunately this can give those within Functional Medicine and/or Nutrition a really bad name. However, in a world where an extreme viewpoint will garner much more attention, it's catchier and more appealing to push an agenda that exists on the edge. And if you can pepper the conversation with a lot of threatening, fear-mongering statements, all the better.
And this is my entire problem with Gundry's book.
Look, the truth about Lectins is really very simple. They are plant compounds which vary in their impact on the human digestive system. Much isn't known about them and what we do know suggests that the robustness of the individual is far more indicative of how well-tolerated Lectins are than anything else. Moreover, some Lectins are worse than others, with the Lectins in grains proving more challenging, though this may or may not be to do solely with the Lectin content as there are other compounds in grains which affect digestibility.
For those with immune difficulties, digestive dysbiosis and/or genetic influences which affect their ability to tolerate certain proteins, building a diet entirely based on Lectin-containing foods is probably not a sensible idea. In these cases, some attention to the Lectin-containing foods is likely to be wise. However, investing in building a robust gut, a peaceful immune system (by removing extraneous stressors) and a diverse microbiome is likely to assist with digesting and tolerating Lectins in all cases, irrespective of individual sensitivity.
The problem with books that promote the ideology of 'good' and 'bad' foods is that they perpetuate the idea that foods can be dangerous. In suggesting that there are 'hidden dangers in "healthy" foods that cause disease and weight gain' (literally on the front cover as the subtitle) this increases the impression that our nutritional landscape is a difficult one, filled with foods that are slowly poisoning us. In fact, the way nutrition is presented just plays on people's fears around it, rather than sagely and calmly presenting the facts. I fairly simply managed to lay out the facts in just two paragraphs above. It's not as catchy, sure - but it helps far more people.
If the Lectins you are consuming are responsible for your disease and weight gain then the problem isn't in the fact that you're consuming Lectins. It may be exacerbated by eating Lectin-containing foods, but unless you are coeliac or profoundly gluten-sensitive it is highly, highly unlikely that consuming Lectins alone is the sole thing responsible for derailing your health picture. Instead, there are likely multiple causes, of which consuming a diet high in Lectins might be just one - and it is only impactful because of the poor resilience of the rest of your body.
Lack of sleep, a dysregulated microbiome, not chewing your food properly, eating and living in a high stress state, living on coffee and alcohol, using anxiety as a fuel and motivating factor in your life... it is these things that will make your immune and digestive systems vulnerable to the impact of Lectins. If you are relatively healthy and taking care of yourself, your body is well equipped to break down and to deal with Lectins. In most cases.
Because that's important to state... Yes, there will always be exceptions to the details I have laid out here. I myself am one of those exceptions - it doesn't matter how on point my health is I'm always going to struggle with Lectins because I have a lot of mast cells in my gut which really, really don't like the Lectins coming into contact with them. But that does not mean that I insist that all of my clients eat the way I do - my body is simply different. Nor do I label everything that my body cannot tolerate or struggles with "bad" or an "enemy". That is just loaded terminology which gives everybody in my line of work a bad name.
Food is not a meritocracy and there are no 'good' and 'bad' foods. It is my belief that there are foods that serve our optimal health and foods that detract from it. Which foods these are will depend entirely upon the individual, the time in their life and the rest of the inputs/stresses/challenges that they are currently facing... again, it's nothing to do with the food itself being 'designed' to be toxic.
More than this, a lot of how your body responds to and accepts food will depend a lot on how we feel about it.
And this last part is why I am so vehemently against dogma which portrays food as 'good' or 'bad' - such as in Gundry's book. Believing something is so, particularly when it's something that you're about to ingest, makes your nervous, immune and digestive systems respond accordingly. Those Mast Cells I mentioned above - they don't typically love Lectin-containing foods. But I know from personal experience that I can change absolutely nothing about the food that I have eaten - except my perception of it - and the food can have a drastically different impact. I can also consume something and watch my body start to react - and then calm it all down using just my perspective alone...
(NOT RECOMMENDED FOR ANYONE WITH PROVEN ALLERGIES... CONSULT YOUR DOCTOR... ALL THE USUAL DISCLAIMERS APPLY HERE...)
So yes, food is MUCH more complex than 'good' or 'bad', Lectins, anti-nutrients or histamine/salicylates/oxalates/FODMAPs etc. Food is rarely consumed without context. It is books like Gundry's which worry me. Even my mother read it and said, "I'm scared about what on earth to eat now."
This should NEVER happen. Eating and nourishing our bodies should never be a place where fear is allowed to take hold. You may very well be one of the people for whom the foods mentioned above really do aggravate and create reactivity. I am in no way saying that this is 'all in your head', because it isn't. What I am saying is that your issue with Lectins likely stems from something inside you and books, websites, blogs and dietary programs which reinforce the sense that there is danger in the nutritional world itself are doing you NO favours because they are stoking your fear - fears that in some (many) cases are unfounded.
If you are someone who is struggling with feeling like every food might be an enemy, or someone who has become so confused or lost about what is right or wrong to eat, please reach out to talk to someone and DON'T read books like this and try to implement their instructions. You don't have to reach out to me, though you're welcome to - but I would encourage that whoever you to reach out to is NOT someone who sits on or promotes an extreme, someone who isn't promising you that cutting out something will heal your life and who isn't selling the ideology that certain foods are 'bad' foods. If you would like to talk to me about what's happening for you and see if I can help you work out a better way to tackle your nutrition, please get in touch today.