This one is a bit messy and long. The reason is pretty simple. Lectins are in absolutely every plant and animal. So if you try to “not eat lectins” that isn’t going to work.
The answer, in my opinion, is that all lectins are not created equal; some are lethal, some do nearly nothing, and some just make you a little off your best. Discrimination between the lectins matters.
Then the other complication is that some things, that we have already realized are evil, and some others that are just bad for some people, are all lectins. Take wheat. We think of it as a “wheat problem” but the specific thing that’s the problem is a lectin. We are defining a dozen different diseases that all have a common thread.
So what is that thread?
Lectins are a protein or protein fragment that bonds to a sugar. That’s both simple to grasp, and terribly complex, because there are literally thousands of lectins and sugars of dozens of kinds get expressed (or show up) on the surface of cells and ends of long molecules. Then the combinations run into massively larger numbers (for just 1000 lectins interacting with 1000 sugar containing molecules taken only as “one each” you get a million binary pairs)
What this effectively means is that you can’t just test all of the interactions. At best what you can do is test if a given plant or animal makes you (or a group of people) more or less healthy. Essentially “How do you feel when you eat this?”. In many cases the answer is looking like “I don’t feel well”.
The other thing driving me to this posting (other than just curiosity) is that when I look at the things I already know I react to they are on the list of high lectin foods that are “to be avoided” on a low lectin diet. Tomatoes. Cows milk. Corn. A friend who reacts to wheat. Eventually you start to see a pattern…
Why do things have lectins? They do a lot of functions in the cell. Moving things around from one place to another in the cell. Mediating immunity. And the one that is likely the problem: Killing off animals that want to eat them.
Just to put that last point in perspective: Ricin, one of the most poisonous things on the planet, is a lectin from a bean. Eating a few Red Kidney Beans that were cooked at low temperatures will make you sick (and can kill you) thanks to a lectin.
Furthermore, some of the actions of lectins are immune system mediated, so what makes one person react will be different from what makes the next person react. Depending on your particular immune system, your history of exposure, and your genetic predisposition. I, for example, have the immunoglobulin “E” called IgE. That’s the one that gives you allergies but also gives faster and better response to some parasites like malaria. Not everyone has it. Blacks, for example, evolved sickle cell trait to fight malaria instead; and many from the Levant evolved higher “oxidative stress” and that is set off by Fava Beans. The disease is named Favism, but having the trait is helpful in fighting off malaria. So a complex interaction of genetics, history, and exposure.
Then there are the “degenerative diseases”. Things like heart disease, atherosclerosis, arthritis, and several other “auto immune” diseases like lupus. These have had a bunch of different “causes” imagined for them. Like the physical wearing out hypothesis for arthritis. Yet that seems silly. We grow repair and replacement cartilage when injured; and that isn’t immune system mediated. Could they be related to ingestion of a low grade toxin for years, too? Seems there’s some M.D.s who are starting to say “Yes.” and with some evidence to back up their assertion.
So what I’m going to do is point at some articles, give abstracts of them, and some of my comments as a bit of a review of my reaction to the articles.
The overall impression I’ve got is that the usual suspects are rushing off to a Food Fad again; while the medical camp is dividing into “Does so! Does NOT!” factions. Yet there is clear evidence for “issues” in the medical literature and a lot more in the anecdotal reports of individuals. I’m one of those individuals. I can modulate a general inflammatory response AND a specific joint arthritic discomfort with specific foods that are on the list of those with high problematic lectins and / or associated with “leaky gut”.
This link is the most approachable and the most “centered” and correct that I’ve found so far. I’ll be quoting some of it later, but for now, if you want to get a better description of some of this along with pretty pictures, start here:
These 50 Foods Are High In Lectins: Avoidance or Not?
SuperfoodlyOctober 8, 2017
There are thousands of foods which have allergic reactions associated with them and in theory, it’s possible for any food to be an allergy candidate.
However the actual part of a food we can potentially be allergic to are the proteins and their pollens. Not all foods have those, or at least not in high concentrations.
Can you be allergic to apples? Yes but since they contain so little protein content, even if you are allergic, it’s unlikely you will have noticeable side effects like a skin rash, hives, or sneezing. Among those eaten, Gala apples have the least amount of protein and Starking have the most. The latter also tends to trigger more pronounced results in skin prick tests.
It’s not just a coincidence that the 8 most common food allergens are protein-rich:
It then goes on to explain what lectins are and that these foods also have lots of lectins.
Leaky Gut – Intestinal Hyperpermeability
One of the up-front things to get familiar with is the concept of how the gut works and how it might be compromised. The gut is basically one strong layer of cells that isolate the inside from the outside, along with a mucus coating and some backing structures. That cell layer has what are called “tight junctions” with their neighbor cells. These keep out all the “stuff” you have not digested.
Some lectins cause that “tight junction” to become loose or leaky. Then various protein fragments, undigested, can pass into the blood stream, attach to things or deposit in places where they do not belong, and then cause troubles. Either directly, or just by having your immune system say “What is this alien protein doing here?” and attacking those structures – even if they are ‘you’ and important to your function.
The thesis is that depending on the lectin, it can bind to the cells of joints (arthritis), the arteries (atherosclerosis, heart attack, stroke), the brain cells (Alzheimers) or the cells that make insulin (diabetes) and potentially more. In some cases there is research showing the specific lectins, their binding sites, and the specific responses along with the specific antibodies that can be used as a diagnostic tool.
In particular, one of the parts of gluten acts directly to promote leaky gut. It is a promoter of “zonulin” that is the natural gut permeability regulator.
CD is Celiac Disease.
When you see “Gliadin” realize it is part of gluten in wheat.
From the Wiki:
“Gliadins and glutenins are the two main components of the gluten fraction of the wheat seed.”
Now back to the NIH link:
2.3. Gluten, Gliadin and CD
Gliadin epitopes from wheat gluten and related prolamins from other gluten-containing cereal grains, including rye and barley, can trigger CD in genetically susceptible people. The symptoms of this disease are mucosal inflammation, small intestine villous atrophy, increased intestinal permeability and malabsorption of macro- and micronutrients. CD, a chronic inflammatory disorder mediated by T-cells, is preceded by changes in intestinal permeability and pro-inflammatory activity of the innate immune system. Gliadin immunomodulatory peptides can be recognized by specific T-cells, a process that can be enhanced by the deamidation of gliadin epitopes by tissue transglutaminases that convert particular glutamine residues into glutamic acid resulting in a higher affinity for HLA-DQ2 or DQ8 expressed on antigen-presenting cells (APC). Serum antibodies, among which are antibodies against tissue transglutaminases, are also found in CD. The HLA-DQ2 or HLA-DQ8 is expressed in 99.4% of the patients suffering from CD, however, interestingly enough, there is a group of HLA-DQ2/DQ8-negative patients suffering from gastrointestinal symptoms that respond well to a gluten-free diet. This group of “gluten-sensitive” patients does not have the CD serology and histopathology, but does present the same symptoms and shows improvements when following a gluten-free diet.
2.4. Gliadin and Immunity
There are at least 50 gliadin epitopes that exert immunomodulatory, cytotoxic and gut-permeating activities that can be partially traced back to different domains of α-gliadin. Where some immunomodulatory gliadin peptides activate specific T-cells, others are able to induce a pro-inflammatory innate immune response. Stimulation of immune cells by gliadin is not only restricted to CD patients; the incubation of peripheral blood mononuclear cells (PBMC) from healthy HLA-DQ2-positive controls and CD patients with gliadin peptides stimulated the production of IL-23, IL-1β and TNF-α in all donors tested. Nevertheless, the production of cytokines was significantly higher in PBMC derived from CD patients. Similar results were obtained by Lammers et al., who demonstrated that gliadin induced an inflammatory immune response in both CD patients and healthy controls, though IL-6, Il-13 and IFN-γ were expressed at significantly higher levels in CD patients. IL-8 production was only expressed in a subset of healthy and CD individuals after stimulation with a specific gliadin peptide and appeared to dependent on the CXCR3 chemokine receptor only in CD patients. Sapone et al. showed that in a subset of CD patients, but not in gluten-sensitive patients (with 36% of the studied individuals in this group being HLA-DQ2/DQ8-positive), there is an increased IL-17 mRNA expression in the small-intestinal mucosa compared to healthy controls. The same group showed that in a subset of gluten-sensitive patients (with about 50% of the studied individuals being HLA-DQ2/DQ8-positive) there is a prevailing stimulation of the innate immune system, while in CD, both the innate and adaptive immune system are involved.
2.5. Gliadin and Intestinal Permeability
In order for gliadin to interact with cells of the immune system, it has to overcome the intestinal barrier. Gliadin peptides cross the epithelial layer by transcytosis or paracellular transport. Paracellular transport occurs when intestinal permeability is increased, a feature that is characteristic for CD. It is indicated by several studies that increased intestinal permeability precedes the onset of CD and is not just a consequence of chronic intestinal inflammation. Gliadin has been demonstrated to increase permeability in human Caco-2 intestinal epithelial cells by reorganizing actin filaments and altering expression of junctional complex proteins. Several studies by Fasano et al. show that the binding of gliadin to the chemokine receptor CXCR3 on epithelial IEC-6 and Caco2 cells releases zonulin, a protein that directly compromises the integrity of the junctional complex. Although zonulin levels were more up-regulated in CD patients, zonulin was activated by gliadin in intestinal biopsies from both CD and non-CD patients, suggesting that gliadin can increase intestinal permeability also in non-CD patients, yet increased intestinal permeability was not observed in a group of gluten-sensitive patients.
3. Increased Intestinal Permeability
3.1. Increased Intestinal Permeability is Associated with Disease
Chronically increased intestinal permeability (or leaky gut syndrome) allows for the increased translocation of both microbial and dietary antigens to the periphery which can then interact with cells of the immune system. Shared amino acid motifs among exogenous peptides (HLA-derived peptides and self-tissue) may produce cross-reactivity through immunological mimicry, thereby disturbing immune tolerance in genetically susceptible individuals. Not surprisingly, increased intestinal permeability has been associated with autoimmune diseases, such as type 1 diabetes, rheumatoid arthritis, multiple sclerosis, but also with diseases related to chronic inflammation like inflammatory bowel disease, asthma, chronic fatigue syndrome and depression. The latter two conditions see patients with significantly greater values of serum IgA and IgM to LPS of gram-negative enterobacteria compared to controls, implying intestinal permeability is increased in these patients.
3.2. Intestinal Barrier Function and Inflammation
The intestinal barrier allows the uptake of nutrients and protects from damage of harmful substances from the gut lumen. Macromolecules that can be immunogenic like proteins, large peptides, but also bacteria and lectins, can be endocytosed or phagocytosed by enterocytes forming the epithelial layer of the gut. Absorbed proteins will generally enter the lysosomal route and will be degraded to small peptides. Normally, only small amounts of antigen pass the barrier by transcytosis and interact with the innate and adaptive immune system situated in the lamina propria. Highly specialized epithelial microfold (M) cells function as active transporters of dietary and microbial antigens from the gut lumen to the immune system, where either a pro-inflammatory or tolerogenic immune response can be generated. The paracellular route is regulated by the junctional complex that allows the passage of water, solutes and ions, but under normal conditions provides a barrier to larger peptides and protein-sized molecules. When the barrier function is disrupted, there is an increased passage of dietary and microbial antigens interacting with cells of the immune system (Figure 1).
OK, lots of words, what does it mean?
Pretty simple at the base of it. We can show a direct set of reactions that results in zonulin opening the “tight junctions” and letting a load of foreign molecules into the body. This is an essential action of the protein in wheat. It ought to happen to greater or lesser degree to everyone.
Then, for many folks, they can react to those foreign compounds (and bacteria…) in various ways depending on where the go and to what they attach.
This is seen in folks with CD, in folks without CD, and in folks with a load of other diseases specifically listed:
“increased intestinal permeability has been associated with autoimmune diseases, such as type 1 diabetes, rheumatoid arthritis, multiple sclerosis, but also with diseases related to chronic inflammation like inflammatory bowel disease, asthma, chronic fatigue syndrome and depression.”
That sure looks like a pretty strong case against eating a lot of wheat and for reducing the quantity of it, perhaps to zero. IMHO, anyone with one of those autoimmune diseases ought to at least try a gluten free diet and see if after a week or two they are feeling better or worse. If you are fine and eat lots of wheat, consider yourself lucky; given the clear biochemistry in the gut.
(Obligatory paranoid disclaimer: I’m not a Doctor. I don’t even play one on TV or the internet. These are just my ideas as I intend to apply to myself. YMMV and don’t do ANYTHING without consulting your physician and handing them a load of money.)
Once Inside The Body
Now the kicker is that this lets a load of other compounds in, including those indigestible lectins that can then bind to sugars on cells all over your body that then causes your immune system to take notice and attack.
From that Superfoodly link at the top:
Lectin intolerance and toxicity affects all of us to at least some degree.
Lectins were discovered almost 130 years ago, in 1888. That’s well over a decade before aviation, something we have since mastered. Yet these commonly occurring compounds largely remain a mystery. And while you may not be flying everyday, it’s guaranteed that you are eating foods containing lectin on a daily basis.
Seems like something we really ought to know more about, right?
Glyca-binding proteins (GBPs) are a category of proteins which bind specifically to certain sugar molecules. The “glyca” is the same prefix you see in the word glycation. That describes what happens after a protein or fat binds with a sugar molecule.
This binding process can cause inflammation and the creation of advanced glycation end products (AGEs), which are compounds associated with numerous age-related diseases. It’s why the apparent anti-glycation benefits of carnosine are so intriguing.
While some is influenced by diet, most of the glycation in your body will take place no matter what you eat.
So once in, bad stuff happens. Oh Joy. Back at that NIH link:
3.3. The Role of Zonulin Signaling on Intestinal Permeability
Intestinal permeability is a measure of the barrier function of the gut which relates to the paracellular space surrounding the brush border surface of the enterocytes and the junctional complexes consisting of tight junctions, adherent junctions, desmosomes and gap junctions. The junctional complexes are regulated in response to physiological and immunological stimuli, like stress, cytokines, dietary antigens and microbial products. As mentioned before, zonulin, a protein identified as prehaptoglobulin-2 (the precursor of haptoglobin-2) is also a regulator of intestinal permeability. Haptoglobin-2, together with haptoglobin-1, is one of the two gene variants of the multifunctional protein haptoglobin and is associated with an increased risk for CD (homozygotes and heterozygotes) and severe malabsorption (homozygotes). The haptoglobulin-2/zonulin allele has a frequency of about 0.6 in Europe and the U.S.A, but varies throughout the world depending on racial origin.
So folks “with issues” need to avoid stress too. If stress sets you off, getting rid of the wheat driven increase in zonulin might also be helpful (ought to be…). Then that “microbial products” indicates why all the probiotics and “fecal transplants” can do things. Once the gut is leaky, what leaks in matters a lot more.
3.4. High Zonulin Levels are Observed in Auto-Immune and Inflammatory Diseases
Zonulin signaling is proposed to cause rearrangements of actin filaments and induces the displacement of proteins from the junctional complex, thereby increasing permeability. Gliadin peptides initiate intestinal permeability through the release of zonulin, thereby enabling paracellular translocation of gliadin and other dietary and microbial antigens, which by interacting with the immune system give rise to inflammation. In this manner, a vicious cycle is created in which, as a consequence of the persistent presence of pro-inflammatory mediators, intestinal permeability will increase even further. High zonulin levels (together with increased intestinal permeability) have been observed in autoimmune and inflammatory diseases like CD, multiple sclerosis, asthma and inflammatory bowel disease and the haptoglobin polymorphism is associated with rheumatoid arthritis, ankylosing spondylitis, schizophrenia and certain types of cancer.
The zonulin inhibitor Larozotide acetate was tested in an inpatient, double-blind randomized placebo-controlled trial. The group of CD patients in the placebo group that were exposed to gluten showed a 70% increase in intestinal permeability, while no changes were seen in the group exposed to Larazotide acetate. Also gastrointestinal symptoms were significantly more frequent in the placebo group. These results suggest that in CD patients, when intestinal barrier function is restored, autoimmunity will disappear while the trigger (gluten) is still there. Besides gliadin from wheat gluten, the lectin wheat germ agglutinin (WGA) has also been shown to stimulate cells of the immune system and increase intestinal permeability, as we will now discuss further.
The biggy in that last paragraph is that there is a simple “fix” in larozotide acetate. Were I suffering from one of those diseases, like Lupus or MS, I’d certainly try gluten avoidance and start researching larozotide acetate.
Skipping down into the WGA section (the stuff from the germ of the grain not the white flour part – so the added bit from “whole grain”.)
4.4. WGA and Intestinal Permeability
After ingestion, WGA is capable of crossing the intestinal barrier. In animal models, WGA has been shown to reach the basolateral membrane and walls of the small blood vessels in the subepithelium of the small intestine. WGA can be phagocytosed by binding to membrane non-receptor glycoproteins, a process that has been observed in Caco-2 cells. WGA can also be endocytosed by antigen sampling M-cells or by enterocytes via binding to epidermal growth factor receptors. Another possible route for lectin entry into the periphery is by paracellular transport, a process that can be further aggravated by the binding of gliadin to the chemokine receptor CXR3 on enterocytes.
WGA itself has been found to affect enterocyte permeability. Investigations by Dalla Pellegrina et al. showed, in vitro, that exposure to micromolar concentrations of WGA impairs the integrity of the intestinal epithelial layer, allowing passage of small molecules, like lectins. At the basolateral side of the epithelium, WGA concentrations in the nanomolar range induced the secretion of pro-inflammatory cytokines by immune cells. This may further affect the integrity of the epithelial layer, heightening the potential for a positive feedback loop between WGA, epithelial cells and immune cells. When combined, these mechanisms are likely able to significantly increase the percentage of consumed WGA that can cross the epithelial layer compared to the low percentage of WGA crossing by means of transcytosis (0.1%) alone. This suggests that, together with gliadin, WGA can increase intestinal permeability, resulting in an increase of translocating microbial and dietary antigens interacting with cells of the immune system.
So much for that whole “Whole Wheat Is Better” thing… There are other lectins that “have issues” but wheat looks to be somewhat unique in this strong promotion of “leaky gut” and letting loads of the others in.
Paleo Diet & Avoiding Grains
They eventually look at the overall “Paleo Diet” impacts:
6.3. Health Effects of the Paleolithic Diet
There are few studies that investigate the influence of a paleolithic type diet comprising lean meat, fruits, vegetables and nuts, and excluding food types, such as dairy, legumes and cereal grains, on health. In domestic pigs, the paleolithic diet conferred higher insulin sensitivity, lower CRP and lower blood pressure when compared to a cereal-based diet. In healthy sedentary humans, the short-term consumption of a paleolithic type diet improved blood pressure and glucose tolerance, decreased insulin secretion, increased insulin sensitivity and improved lipid profiles. Glucose tolerance also improved in patients suffering from a combination of ischemic heart disease and either glucose intolerance or type 2 diabetes and who had been advised to follow a paleolithic diet. Control subjects who were advised to follow a Mediterranean-like diet based on whole grains, low-fat dairy products, fish, fruits and vegetables did not significantly improve their glucose tolerance despite decreases in weight and waist circumference. Similar positive results on glycemic control were obtained in diabetic patients when the paleolithic diet was compared with the diabetes diet. Participants were on each diet for three months, whereby the paleolithic diet resulted in a lower BMI, weight and waist circumference, higher mean HDL, lower mean levels of hemoglobin A1c, triacylglycerol and diastolic blood pressure, though levels of CRP were not significantly different. Although the paleolithic diet studies are small, these results suggest that, together with other dietary changes, the withdrawal of cereal grains from the diet has a positive effect on health. Nevertheless, because these studies are confounded by the presence or absence of other dietary substances and by differences in energy and macronutrient intake, factors that could all affect markers of inflammation, it is difficult to make a concise statement on the impact of cereal grains on these health outcomes.
I’ll leave the rest of that paper for folks to look at on their own. The short form is “Paleo Good” but maybe not needed for everyone.
Other Lectin Effects – Arthritis
Related is a more general look at lectins, especially in beans:
A key point about legume lectins is that they are easily broken down by prolonged boiling and substantially made harmless by pressure cooking. Soaking helps. So soak over night with changes of water, then pressure cook, and you need not worry about it.
After an introduction about cooking kidney beans and what happened when some folks did not, they get down to the business of how various lectins, once inside you, can cause issues.
BMJ. 1999 Apr 17; 318(7190): 1023–1024.
Do dietary lectins cause disease?
The evidence is suggestive—and raises interesting possibilities for treatment
David L J Freed, Allergist
This suggests that in humans IgA nephropathy might be caused or aggravated by wheat lectin; indeed a trial of gluten avoidance in children with this disease reported reduced proteinuria and immune complex levels.
Of particular interest is the implication for autoimmune diseases. Lectins stimulate class II HLA antigens on cells that do not normally display them, such as pancreatic islet and thyroid cells. The islet cell determinant to which cytotoxic autoantibodies bind in insulin dependent diabetes mellitus is the disaccharide N-acetyl lactosamine, which must bind tomato lectin if present and probably also the lectins of wheat, potato, and peanuts. This would result in islet cells expressing both class II HLA antigens and foreign antigen together—a sitting duck for autoimmune attack. Certain foods (wheat, soya) are indeed diabetogenic in genetically susceptible mice. Insulin dependent diabetes therefore is another potential lectin disease and could possibly be prevented by prophylactic oligosaccharides.
Another suspect lectin disease is rheumatoid arthritis. The normal human IgG molecule possesses carbohydrate side chains, which terminate with galactose. In rheumatoid arthritis much of the galactose is missing, so that the subterminal sugar—N-acetyl glucosamine—is exposed instead. These deficient IgG molecules feature strongly in the circulating immune complexes that cause fever and symptoms. In diet responsive rheumatoid arthritis one of the commonest trigger foods is wheat, and wheat lectin is specific for N-acetyl glucosamine—the sugar that is normally hidden but exposed in rheumatoid arthritis. This suggests that N-acetyl glucosamine oligomers such as chitotetraose (derived from the chitin that forms crustacean shells) might be an effective treatment for diet associated rheumatoid arthritis. Interestingly, the health food trade has already siezed on N-acetyl glucosamine as an antiarthritic supplement.13
Among the effects observed in the small intestine of lectin fed rodents is stripping away of the mucous coat to expose naked mucosa and overgrowth of the mucosa by abnormal bacteria and protozoa. Lectins also cause discharge of histamine from gastric mast cells,15 which stimulates acid secretion. So the three main pathogenic factors for peptic ulcer—acid stimulation, failure of the mucous defence layer, and abnormal bacterial proliferation (Helicobacter pylori) are all theoretically linked to lectins. If true, blocking these effects by oligosaccharides would represent an attractive and more physiological treatment for peptic ulcer than suppressing stomach acid. The mucus stripping effect of lectins also offers an explanation for the anecdotal finding of many allergists that a “stone age diet,” which eliminates most starchy foods and therefore most lectins, protects against common upper respiratory viral infections: without lectins in the throat the nasopharyngeal mucus lining would be more effective as a barrier to viruses.
But if we all eat lectins, why don’t we all get insulin dependent diabetes, rheumatoid arthritis, IgA nephropathy, and peptic ulcers? Partly because of biological variation in the glycoconjugates that coat our cells and partly because these are protected behind a fine screen of sialic acid molecules, attached to the glycoprotein tips. We should be safe. But the sialic acid molecules can be stripped off by the enzyme neuraminidase, present in several micro-organisms such as influenzaviruses and streptococci. This may explain why diabetes and rheumatoid arthritis tend to occur as sequelae of infections. This facilitation of lectins by micro-organisms throws a new light on postinfectious diseases and makes the folklore cure of fasting during a fever seem sensible.
Alternative medicine popularisers are already publishing articles about dietary lectins, often with more enthusiasm than caution, so patients are starting to ask about them and doctors need to be armed with facts. The same comment applies to entrepreneurs at the opposite end of the commercial spectrum. Many lectins are powerful allergens, and prohevein, the principal allergen of rubber latex, is one. It has been engineered into transgenic tomatoes for its fungistatic properties, so we can expect an outbreak of tomato allergy in the near future among latex sensitive individuals. Dr Arpad Pusztai lost his job for publicising concerns of this type (20 February, p 483).
Note that last bold bit about transgenic tomatoes… This paper was from 1999 and it was just a few years after that when I began having stiff and ache prone joints when eating lots of tomato foods. And people wonder why I’m not keen on GMO foods…
So the general point of that section was that we are all different, those of use with modified IgG of the kind manifest in rheumatoid arthritis are more reactive to lectins, and there are some other protective bits too.
Nice to know, but if stopping wheat can cut down the lectin absorption while dropping out some high lectin foods can reduce that available to absorb all while cooking things longer and hotter destroys more of what’s in it: Why the hell not see if you stop hurting then? As a side effect, it also looks to improve diabetic responses and general inflammatory problems.
About Those Cows
From that Superfoodly link:
Based on research to date, the highest overall animal source appears to be dairy.
Mammals only produce milk during reproduction to feed their newborns. Since reproduction is an animal’s most important task in life, it’s interesting to note that it also involves their most significant use of lectins – the mother’s milk is loaded with it.
This fends of predators – other species – from considering that milk as being their own potential food source. That ensures the newborn is more likely to get this vital source of food, rather than someone else. Keep in mind that predators include microscopic organisms, like bad bacteria and fungal infections in a baby’s digestive tract.
So why are these milk lectins nutritious for the baby, while being potentially poisonous to another species?
That’s how lectins work. They ensure the food is good for who should get it, but not good for everyone.
In particular, there was an odd mutation happened some thousands of years back that make northern European Cows different from southern ones. French and Italian good, German and Swedish not so much…
Two thousand years ago, Northern European cows suffered a genetic mutation and began producing a lectin-like protein in their milk called Casein A1 (the normal cow makes Casein A2, a safe protein). Unfortunately, Casein A1 cows are heartier and give more milk, so most cows in the world (except those in Southern Europe), produce milk that’s harmful to humans. I’ve found that most people who react negatively to milk, get mucous from drinking milk, or think that they are lactose intolerant, in fact are affected by the lectin-like protein Casein A1, but tolerate Casein A2 from sheep, goats, buffaloes, and French, Italian, and Swiss milk products and cheeses.
As I react by being arthritic and congestive on “cows milk” I’m likely in that group. I do fine on sheep and goat milk, cheeses and yogurt. This may also explain some of the longer healthier life “hot spot” around the Mediterranean. Not just the general diet, but the specific milk in the cheeses and cream sauces…
I’ll be checking out Whole Foods and related “health food stores” to see if any “Casein A2” cows milk is on sale. As Cow’s milk gets subsidy but goat milk does not, it would be nice to find I could use a subsidized form…
Note that this Casein A1 will also be showing up in cream sauces, cheeses, yogurts, any main courses or sides made with milk… on and on.
BTW, that article is a Q&A with Dr. Steven Gundry, M.D.; who’s written a book about all this. He was a very busy cardiac surgeon doing thousands of surgeries before he decided preventing it in the first place was a higher calling. He is now a strong advocate for lectins as causal of all sorts of diseases, especially heart disease.
Are We Wrong About What Makes Food Healthy?
Some of the foods we think are the healthiest may play a role in leaky gut, autoimmune disorders, and other diseases, says goop contributor, Steven Gundry, M.D., whose research may change the way we all think about “healthy” food in the future. Gundry, who focuses on autoimmunity and microbiome disorders, sees lectins—proteins found in some plants, designed to protect them from predators—as the root cause of many diseases. As Gundry explains, lectins are like a smart bomb to the body; they can have toxic or inflammatory effects that underlie gut-related health issues like leaky gut, autoimmunity, and weight gain. His forthcoming book on the topic, The Plant Paradox, is a fascinating exploration of the evolution of plants and animals, and our relationship to the food we eat today, along with useful practical tips, eating plans, and health-boosting recipes. If you’re like us, Gundry’s insight into the modern diet, particularly concerning which plants are healthy and not, will surprise you:
Reading the rest of that link is well worth it, along with this one:
Could Diet Cure Arthritis?
Gut and autoimmunity expert Dr. Steven Gundry, author of The Plant Paradox, has been making waves with his research on lectins—a type of protein found in some plants that he believes to be at the root of most diseases. (See why in this goop piece.) Gundry’s diet recommendations have proved particularly effective for patients struggling with arthritis—a condition he not surprisingly has an unconventional stance on, and one that he connects to a breakdown in the gut. We interviewed him about the causes of osteoarthritis (the most common form of arthritis) and the autoimmune disease rheumatoid arthritis, and what he sees as the potential cure:
My research [see more in Gundry’s book The Plant Paradox] has shown that both RA and osteoarthritis can be caused by proteins in plants and some milk products, called lectins, which break the gut’s barrier (i.e. leaky gut), releasing these proteins into our blood circulation. In the case of RA, lectins confuse the immune system (called molecular mimicry), and cause it to attack the synovial surface of joints and the lining of blood vessels.
In the case of osteoarthritis, lectins have been shown to attach to the sugar molecule in cartilage called sialic acid, prompting a direct immune attack on the cartilage itself. This can lead people to have their hip or knee replaced—because there is no cartilage left in their hip/knee joint (often referred to as “bone on bone”).
Of interest, societies that typically eat very low lectin diets—like the Kitavans and Okinawans—have extremely low incidence of arthritis or autoimmune diseases of any kind.
Moreover, human studies that used a novel lectin (seeds from the Maackia amurensis tree) that actually prevents other lectins from binding to receptors in cartilage was shown to prevent cartilage breakdown, which could make it an effective treatment to RA and OA.
What’s your treatment plan for patients with arthritis?
In either form of arthritis (RA or OA), I ask people to remove the major lectin-containing foods from their diet: These include all grains and pseudograins like quinoa, all beans unless pressure cooked, all nightshade vegetables (such as potatoes, eggplant, tomatoes, peppers, and goji berries), as well as squashes and cucumbers. American nuts and seeds—cashews, peanuts, sunflower, pumpkin, and chia—are also removed. Finally, I ask people to avoid all Casein A1 milk products. Cheese and milk products from goat, sheep, and Southern European cows, which make Casein A2, a safe protein, are okay and increasingly available in the US.
I show how to repopulate the normal gut microbiome using specific probiotics like BC30.
Importantly, I stress the need for the prebiotics that feed friendly bugs in our gut. These include inulin-containing (fiber) foods like jicama, artichokes, radicchio, endive, and Jerusalem artichokes.
I encourage patients to eat resistant starches as well, like sweet potatoes, taro root, sorghum, and cassava because because they feed friendly bacteria that guard the wall of your gut, creating a barrier against lectins.
I urge people to get polyphenols—like grape seed extract or pycnogenol—in their diet because polyphenols cause our gut to make anti-inflammatory compounds. (Many patients get their daily dose of polyphenols from my Vital Reds supplement.)
It is important to realize that you do not have to “live” with arthritis. It should not be managed, it should be cured!
As you can see, he goes a lot further than just saying to cook the beans a lot and avoid whole wheat…
Searching on his name finds a lot more articles, and there are interviews / videos on YouTube worth the watching.
Some Things To Do
From that Superfoodly link:
If they’re in everything, where do you begin?
Just because a given food might have more of them, that does not automatically mean it’s a problem.
This is because there are thousands of different types in your diet and their effects in the human body can vary greatly. From lethal poisoning like ricin, to having no effect at all.
With that caveat said, based on the limited knowledge known today, even though they’re not be apples to apples, it does seem logical to start by reducing foods that contain lectins in high amounts.
Sure, if there was a 1% concentration in a milk product and a 1% concentration in a wheat product, that doesn’t mean they’re equal in effect. Nor does it mean they’re better than a food with a 2% concentration of a different type.
In an ideal scenario, you would be able to weigh each type accordingly. But with the exception of a few specific foods like kidney beans, any health effect they may have is poorly understood. For that reason, starting with the elimination of the highest known sources isn’t a bad idea.
How to reduce or remove lectins
Rather than avoid these foods entirely, the preparation method is arguably far more important.
Though for some types of foods, cutting them out entirely may be the only effective method for real reduction.
They have a lot of specific recommendations. My generalization of it is:
Eliminate wheat, use other grains if you must but milled grains with the lectin rich bran coats removed. Cook things thoroughly (i.e. don’t eat the cookie dough!)
When the endocrinologist Joseph Charles Aub first discovered wheat germ agglutinin in 1963, its resistance to heat was among the first characteristics noted (24). Yet it was still destroyed after 15 minutes at just 70° C (158° F).
How to remove lectins from beans will involve soaking them overnight, rinsing and draining, then thoroughly cooking. They are not something you want to undercook!
If you don’t have the time to soak canned beans overnight in the fridge, that’s fine, but just make sure you rinse them well before cooking.
The heat will almost entirely destroy lectins in beans, as pointed out in numbers above for kidney. You can entirely deactivate lupin, fava, and soybean lectins when you boil them at 100° C (212° F) for at least 10 minutes (26).
With lower temperatures, that’s not the case. Cooking legumes at 70° C (158° F) for several hours “has little or no effect” (27).
Soy milk is heated (pasteurized) but is that for at least 10 minutes? The manufacturers don’t say. For that reason, veer on the side of caution and avoid soy milk if you are worried there might be active agglutinins in it.
Peanuts are actually a legume. Since this “nut” is always sold roasted, a lower amount of peanut agglutinin (PNA) would be expected.
If you’re using prepared fresh or dry beans/lentils, try sprouting them before cooking. The germination process further reduces the amount they contain.
Raw coffee beans will contain large amounts. Considering how thoroughly those beans are heated – probably more than any other food or drink in your diet – your cup of joe is likely quite safe. Coffee has not been researched though pre and post roasting.
For milk they just say to avoid it. Swapping to goat milk and sheep cheeses has worked well for me. Then on potatoes they suggest swapping to yams.
The most commonly consumed nightshade, potatoes are about 6.5% lectin content on average, which comes primarily from solanum tuberosum agglutinin (STA) (28).
Whether it’s yams, sweet potatoes, purple potatoes, potato starch, or any other form… they’re all going to contain high amounts of glyca-binding proteins. However, the sweet varieties are not part of the nightshade family.
The potato lectins are very stable under heat, acid, and base solutions. This is believed to be due to its high carbohydrate content and the disulfide bonds formed with them.
As my Irish ancestors survived several generations on a diet of mostly potatoes, I’m not going to worry as much about them. It is also the case that in the “elimination diet” I did to see if a food was causing my arthritis, I ate only potatoes for a week and the arthritis stopped. That may just be a “me thing” though and your genetics may vary. Do be sure to peel them as the peel and any green bits are highest in solanine – the potato toxin.
For tomatoes they assert cooking is helpful while Dr. Gundry says most all of the lectin is in the skin and seeds so skin and seed them. I’ve chosen to just avoid them. That whole latext derived added lectin thing.
From watching the Dr. Gundry videos, what’s “in” is largely leaves of things (salads, choy, cabbage, etc.) and roots (turnips, sweet potatoes, carrots…) and meat. Some fruit.
Yes, it makes things like eating Asian or Italian a near impossibility. Forget the potstickers and fried rice, the pasta and pizza. But it might be worth it.
I’m going to give a go at the “gluten free” with a light helping of general lectin reduction. So dumping the breads and morning cereal, the side of rice and the tortilla wrap or burrito. I’ll be keeping beans but using an overnight soak and pressure cooking. Dairy is already over in the Casein A2 land with Goat milk and sheep cheeses.
I’ll be adding more yams / sweet potatoes and squashes. More cabbages, kales, chard, choy, and all the other leaves. I’ll keep the occasional potato just because I know I’m not reacting to them anyway. Peas will be used if cooked well or only added to a crock pot meal if from a can that was cooked well (i.e. not frozen…). And I’ll be hunting up more of those roots I don’t eat much anymore (but grew up eating): turnips, beets, rutabagas, radishes, jicama, and all the rest. Plus the cruciferous vegetables – broccoli, cauliflower, and such. Not to mention avocados, asparagus, and onions ;-)
I can easily make a couple of weeks worth of variety that way. At the end of 2 weeks it ought to be pretty clear if anything is different. Then any foods added back in ought to also be pretty quick to show when they are an issue. (Usually 2 weeks). I can live for 2 weeks without bread and grains, then figure out if adding white rice with my fish is an issue, or not. In theory, hot cooked white rice ought to be fine. Perhaps even very well cooked brown rice.
Given all the evidence above for clear metabolic effects, it seems well worth the effort to see what, if anything, it does for me. IF I end up feeling just swell, but craving those old lecin foods, then I’ll explore the ways to reduce lectins in food. Many of them older more traditional preparation methods like fermenting or soaking:
Cooking methods that use moist heat are helpful for decreasing the number of lectins in plants. Cooking also breaks down some plant starch into simpler carbohydrates. Lectins like to attach to carbohydrates and are removed from the body before they cause negative effects.
Slow cookers are not recommended for preparing kidney beans because the temperature is not high enough to eliminate lectins. Ways to decrease lectins in foods include:
I can work with that…