Lectins and their benefits

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Lectins and their benefits

Postby Searcher » Sat Jan 13, 2018 4:31 am

Lectins are substantially destroyed by overnight soaking and pressure-cooking for as little as 15 minutes. But do they offer benefits, especially in cancer prevention? This seems important because many otherwise healthy foods contain lectins, and avoidable cancer mortality concerns everyone.

from http://www.sciencedirect.com/science/ar ... via%3Dihub

Lectins have potential as oral drugs since they are often resistant to digestion. Importantly they survive passage through the gut, bind to gastrointestinal cells, enter the circulation intact, and maintain their biological activity [7]. Plant lectins from nuts and seeds are the most widely studied, especially Concanavalin A (ConA), a homo-tetramer (4 × 26.5 kDa) with Mn(II) and Ca(II) ions bound at 4 binuclear binding sites per tetramer, and with specificity for mannosyl and glycosyl sugars [8,9]. Interestingly, despite the high similarity amongst plant lectins, many have shown remarkably distinct biological profiles, with a vast range of biological activities which include anti-inflammatory [10], antidepressive [11], anticonceptive [12] and vasodilatory activities [8]. A few lectins have been recently identified as promising antitumour agents, for example ConA and the lectin ML-I from mistletoe are in pre-clinical and clinical trials for human liver cancer and malignant melanoma [13,14].

Lectins appear to inhibit tumour growth in vitro and in vivo by preferential binding to cell membranes of cancer cells or to their receptors [7,15,16]. Nevertheless, this binding leads to different cellular effects that depend on the lectin, such as the activation of protein kinases, or alteration of the production of interleukins leading to immunological responses [7]. Additionally, plant lectins also have a role in triggering different cell death pathways, including apoptosis, necrosis and/or autophagy [3,7,14,17–19]. For example, ML-I (Mistletoe lectin I from Viscum album) and Ricin A (from Ricinus communis) bind to ribosomes and inhibit protein synthesis in vitro, while RBA (Rice bran agglutinin) or WGA (Wheat germ agglutinin) induce G2/M cell cycle arrest and downstream apoptosis [7]. BFL (from Bauhinia forficata) has potent anticancer activity towards MCF-7 cancer cells, causing DNA fragmentation and cell cycle arrest at the G2/M phase, along with inhibition of caspase 9 leading to primary and secondary necrosis [20]. However, determination of their mechanism of action is not always straightforward. Another similar lectin BG2 (from Bauhinia variegata) inhibits cell proliferation of MCF-7 breast cancer cells and HepG2 hepatomas

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Re: Lectins and their benefits

Postby TheresaB » Sat Jan 13, 2018 7:05 pm

Dr Gundry is the personality most often associated with being anti-lectin. He has made certain observations with regard to the context of lectins today:

    1. Our sensitivity to lectins has raised greatly due the recent introduction to chemical and other body disruptors. Such things food additives and food preservatives. The introduction of NSAIDS pain pills in the early 1970’s. Stomach Acid Reducers (Prilosec, Prevacid, Nexium) plastic food packaging/containers (like those containing BPA), petrochemical fertilizers introduced after World War II, herbicides, biocides, food that is now Genetically Modified (GMOs), skin-care products, hand sanitizers, on and on. These are compromising today’s body to deal with lectins.
    2. We eat a lot more lectins today than in the past, largely because the dietary guidelines changed in 1980 resulting in greater carbohydrate consumption. Also, foods today have been modified and contain more lectins than in the past.

Dr Joe Mercola has interviewed Dr Gundry, video, article and transcript available at:
https://articles.mercola.com/sites/articles/archive/2018/01/07/limit-lectins.aspx

In the interview transcript, regarding lectins, Dr Gundry said,
“It may manifest as neuropathy, may manifest as brain fog. It may manifest as arthritis or heart disease. But the longer I’ve done this now, the more I’m convinced that almost every disease process that I’ve come in contact with, we can trace back to, in one way or another, us interacting inappropriately with plant lectins.”


So that explains why Dr Gundry has a such negative opinion of lectins.

However, in the article Dr Mercola wrote after interviewing Dr Gundry.

While Gundry declares lectins the greatest danger in the American diet, especially for those with an autoimmune disease, the truth is some lectins, in small amounts, can provide valuable health benefits. Precision Nutrition states: “Lectins are thought to play a role in immune function, cell growth, cell death and body fat regulation.”9 It seems most problems arise from overconsumption or continued consumption, even in small amounts, of certain lectins your body simply cannot tolerate.
…As you can see, the choice for or against lectins hinges on the particular food in question and the effects lectins have on the eater. While a good deal of controversy has been stirred, the presence of lectins is by no means a sole determinant of the overall value of a particular food to your diet.
(bold font added for emphasis)

So in isolation, lectins aren't bad, but given the context of how lectins are consumed today, Dr Gundry's observations from his patients is there does seem to be more negative correlation than positive.
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Re: Lectins and their benefits

Postby circular » Sat Jan 13, 2018 7:54 pm

Thanks for the context Theresa. I still struggle with whether to be super strict about lectin foods. I'm definitely very low lectin (of the grain, legume and dairy type) and really have been for many years lower than the SAD, but I have very high adiponectin. Do you know if he has any recent clarifications out about the association he's seen as a clinician between high adiponectin and lectin sensitivity? This unresolved issue is a big thorn in my protocol. I can't take him at face value. I need more. Not saying he's right or wrong, I'm just a person who needs more detailed explanations.

High lectin foods have always made me very bloated, which I've usually taken to be a bad thing (certainly uncomfortable), but I sometimes wonder if that is just from the fiber. When I see pictures of people in tribal, hunter-gatherer societies they very often have really bloated bellies and big smiles. I suspect it's because their biomes are happy with all the fibrous foods they eat, whatever the source.
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Re: Lectins and their benefits

Postby Searcher » Sun Jan 14, 2018 6:56 am

Trying to arrive at an informed view here.

The nearest thing to a controlled trial of lectins might be comparison of health outcomes in a population with a lectin-rich diet vs another population with a lectin-poor diet.

The Mediterranean diet is relatively lectin-rich. The widespread American diet, with refined flour and relative concentration of animal foods, is less rich in lectins. The importance of lectins would be more obvious if the Mediterranean diet yielded worse health outcomes. That's the opposite of what's observed. Whatever the adverse effects of lectins, they appear to be outweighed by the other components of the diets.

Another convincing test would be a randomized controlled trial of interventions that reduce the impact of lectins (in the low doses available from soaked and cooked foods). An RCT demonstrating the health advantages of such an intervention would underline the importance of lectins.

The advantage of scientific trials is that they can both prove and disprove hypotheses. Otherwise anyone can look for confirmatory evidence of a cherished hypothesis. That can be misleading.

Meanwhile, the benefits of lectins extend beyond anti-cancer effects to include anti-microbial effects (below).

from https://www.frontiersin.org/articles/10 ... 00671/full

"Plant lectins are known as potent immunomodulatory agents, able to act in both innate and adaptive immune system. They modulate the production of cytokines and other mediators of immune response (such as reactive oxygen and nitrogen species), and, thus, improve the defenses against microbes (Souza et al., 2013; da Silva and Correia, 2014; Coelho et al., 2017). Plant lectins comprise one heterogeneous class of proteins with at least one non-catalytic carbohydrate-binding domain (Coelho et al., 2017). The lectin–carbohydrate interactions have been associated with several biotechnology applications (Komath et al., 2006; de Oliveira Figueiroa et al., 2017). In several cases, the immunomodulatory activity of plant lectins was associated with their interaction with glycan moieties present on the surface of immune cells. Such interaction can result in signal transduction which triggers the effector mechanisms involved in the response against microbial infections (Souza et al., 2013).

Plant lectins play a crucial role in the protection against microbial phytopathogens (Hwang and Hwang, 2011; Kim et al., 2015). Based on this, the antimicrobial and antivirulence actions of several lectins have been demonstrated in vitro against different bacteria of medical importance, as reviewed by several authors (Islam and Khan, 2012; Dias Rde et al., 2015; Coelho et al., 2017; Palharini et al., 2017). Other works have demonstrated the antibacterial effects of lectins using in vitro cell-based assays. For example, a lectin isolated from Aegle marmelos fruit inhibited the adherence and invasion of Shigella dysenteriae to human colonic epithelial cells (HT29 cells), protecting these cells against cell death (induced through apoptosis) (Raja et al., 2011). Similarly, the chitin-binding lectin isolated from the juicy sarcotesta of Punica granatum (named PgTel) showed to have broad-spectrum antibacterial action (inhibiting Gram-positive and Gram-negative bacteria). PgTel was also able to inhibit the invasion of some bacteria to HeLa cells (human epithelioid cervix carcinoma) (Silva et al., 2016b).

The immunomodulatory effects of plant lectins on different immune cells have been also addressed by several authors (Unitt and Hornigold, 2011; Pereira-da-Silva et al., 2012; Souza et al., 2013; da Silva and Correia, 2014; Coelho et al., 2017). Based on this, some works have demonstrated that some well-known immunomodulatory lectins are able to enhance the phagocytic ability of immune cells and their cytokine production in the presence of bacteria (da Silva et al., 2015b; Batista et al., 2017)."

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Re: Lectins and their benefits

Postby TheresaB » Sun Jan 14, 2018 8:48 am

circular wrote:Thanks for the context Theresa. I still struggle with whether to be super strict about lectin foods. I'm definitely very low lectin (of the grain, legume and dairy type) and really have been for many years lower than the SAD, but I have very high adiponectin. Do you know if he has any recent clarifications out about the association he's seen as a clinician between high adiponectin and lectin sensitivity? This unresolved issue is a big thorn in my protocol. I can't take him at face value. I need more. Not saying he's right or wrong, I'm just a person who needs more detailed explanations.


Dr Gundry continues to beat the drum about lectins but I am not aware if there are any recent studies that collaborate what he says. I do know he seems to have convinced Dr Bredesen and Dr Mercola. I also know Dr Mercola and Dr Gundry were writing their most recent books – Fat for Fuel and Plant Paradox – at about the same time. Dr Mercola called Dr Gundry’s book one of the best health books of the year and said he wished he had known of the lectin connection when he was writing Fat for Fuel because he would have included it in his book. Dr Mercola has said his next book, a cookbook to accompany his Fat for Fuel book will incorporate the lectin connection.

FYI, your adiponectin is not a measure of lectins. Adiponectin is merely a traffic sign, not a measuring stick. In other words high adiponectin indicates a person is sensitive or not, but doesn’t not say how much inflammation is going on in the body, that’s TNF-alpha.

Having high adiponectin is usually considered a good thing, it’s a “skinny hormone.” It’s plays an important role in the modulation of glucose and lipid metabolism in insulin-sensitive tissues. Low adiponectin is associated with obesity, insulin resistance, CAD, and dyslipidemia.

Obese people tend to have low adiponectin, but this doesn’t mean they’re not lectin sensitive, it just means the obesity is suppressing adiponectin, they can have low adiponectin and be highly lectin sensitive.

Maybe you already know this, but it was the women’s health study showed that skinny women with high adiponectin levels had a very high incidence of dementia, and this study took ApoE into account. Since this made no sense, Dr Gundry was intrigued and observed is that a lot of his patients with auto-immune disease who had elevated inflammatory markers had elevated adiponectin. He observed that people with rheumatoid arthritis had a very high adiponectin level and most people with rheumatoid arthritis are quite thin. When he took lectins away from these patients, their TNFalphas fell to normal, their joint pain went away, their brain fog went away, whatever.

When I first saw Dr Gundry, I wasn’t noticing any autoimmune issues, brain fog, bloating, excessive congestion, nor had I had my tonsils out, although I did have tonsiloliths when I was younger (little white “stones” that form on the tonsils, they are a collection of dead white blood cells), those are all lectin sensitivity clues. (Sometimes there’s no obvious correlation to lectins, in my 30s I was diagnosed with large fibroids, which Dr Gundry said can develop in response to lectins, one of the fibroids is now shrinking, not sure if that’s menopause or low lectins, or a combination of the two.)

On my first blood test with Dr Gundry three years ago, my adiponectin wasn’t particularly high, but my TNFalpha was high. After following Dr Gundry’s dietary recommendations to avoid lectins in addition to his other recommendations to increase my insulin sensitivity and improve my lipids, my adiponectin has gone up (a good thing), and my TNFalpha, which reflects how much inflammation is being caused by the lectins, has gone down and maintained consistently good, low levels. Also, interestingly, a lab test introduced a year ago also showed that while I don’t have the gene for celiac disease, I react strongly to gluten. Essentially, I have the disease but not the gene, a situation which Dr Gundry says makes sense to him but confounds the celiac researchers. So I continue to stay away from lectins. I should also note on this diet my husband’s congestion went down and his rheumatoid arthritis which was just starting, went away.

I appreciate your skepticism with regard to Dr Gundry. He’s one voice going against conventional wisdom, making recommendations not based on any trials/studies, but rather on his own personal “laboratory” i.e. the thousands of patients he’s treated after transitioning to functional, or as he calls it, restorative medicine 17 years ago. All I can say is it works for me and it has worked for many of his patients. We all must follow our intuition as well as the studies.
-Theresa
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Re: Lectins and their benefits

Postby SusanJ » Sun Jan 14, 2018 9:04 am

Circ, I still think there is a bit of genetics involved here. I just made another post in the histamine thread, and was reminded of my previous post on certain lectins activating mast cells. Perhaps, at least for some of us, certain lectins will activate our immune system in a not so good way. I haven't had time to do a further dive, but a recent histamine reaction has me looking again at how to calm this down once and for all, if possible.

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Re: Lectins and their benefits

Postby Searcher » Sun Jan 14, 2018 2:10 pm

TNF has important protective functions against cancers and infectious diseases such as tuberculosis, histoplasmosis, coccidiomycosis and listeriosis. These are some of the opportunistic infections seen when TNF is suppressed using monoclonal antibodies.

It may well be that the demonstrable anti-cancer and anti-microbial benefits of lectins are exerted partly or wholly through TNF.

Removal of lectins might well help lower TNF levels in auto-immune diseases. In that case, the increased risk of infections and cancers is balanced by some relief from the auto-immune disease.

However, a low level of TNF is not - in itself - favorable. It can signal an increased susceptibility to cancers and infections.

I've been looking for studies that compare all-cause mortality or morbidity among populations on relatively low-lectin and high-lectin diets. No success so far. I think I will continue to use and recommend otherwise healthy foods which happen to contain lectins - with due precautions (soaking and cooking) to avoid acute adverse effects.

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Re: Lectins and their benefits

Postby Julie G » Sun Jan 14, 2018 2:49 pm

Searcher, in the absence of any RCTs testing the lectin hypothesis, I'd encourage you to focus on how YOU feel following a heavy load. I'm far from zealous about avoiding them, but have definitely noticed I feel much worse after an acute ingestion. I experience widespread body pain, a colicky bladder (weird!) and congested sinuses. I've gotten to the point where I pretty much avoid all grains and dairy, soak my nuts and limited legumes. I try to eat plants lower in lectins; but because I eat mostly plants, I've found it really hard to give up tomatoes, peppers and cucumbers. I've also begun taking daily glucosamine chondroitin and D-Mannose (lectin blockers) that seems to help with my lectin sensitivity symptoms.

Interestingly, glucosamine (basically ground up shellfish shells) are also used as "fish paste" in many traditional African dishes. We know that Africa has a high level of E4 carriers who do not go on to develop the chronic diseases of the West when they eat their traditional (extremely varied) diets. I've often wondered if the "fish paste" (lectin blocker) played a part. I recently learned that glucosamine chondroitin is among the supplements that Dr. Rudy Tanzi recommends to prevent Alzheimer's. Nothing proven, but enough hints, especially from listening to my own body, that make me think there's "something" to this.

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Re: Lectins and their benefits

Postby Julie G » Sun Jan 14, 2018 2:53 pm

Oops, I meant to add that I agree overly down-regulating inflammatory pathways has the potential to be harmful; but I suspect that's not an issue for E4 carriers (especially the homozygotes) given our pro-inflammatory allele.

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Re: Lectins and their benefits

Postby Searcher » Sun Jan 14, 2018 4:35 pm

Good points, Julie.

What do you favor for fiber? So many fiber-rich foods have lectins.


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