Lectins - Cell Science Systems

2y ago
16 Views
2 Downloads
658.66 KB
16 Pages
Last View : 21d ago
Last Download : 2m ago
Upload by : Victor Nelms
Transcription

LectinsWhat Are Lectins?Lectins are proteins that bind to specific carbohydrates. They are found in most plants, aswell as in humans, microorganisms, animals, and fish. Therefore, they are found in many ofthe foods we eat. The most concentrated forms appear to be in edible seeds such as thosefound in cereal grains and legumes. The edible seeds of the legume plant (Leguminosae) maybe referred to as pulses, legumes, dried beans, or beans.1 The term "bean" is used most oftenby consumers and will be used in this review. Peanuts and soybeans are in the Leguminosaefamily as well but will be referred to separately.Lectin levels in plants and food crops can vary significantly depending on environmentalconditions such as drought and salinity. Lectin compounds may have evolved in plants as asurvival mechanism, reducing the chance the they will be consumed in large amounts.2Lectins are considered the most widely studiedmolecules in glycobiology. They are capableof reversibly binding monosaccharides,oligosaccharides, and polysaccharides (glycans),including glycans found on cell walls or membranes.These interactions can be as specific as the bindingof antibodies to antigens, or enzymes to targetsubstrates. They are capable of binding multiplemolecules/cells, creating a clump or mass. Dueto their biological activity, some lectins may bedetrimental (occurring as toxins in raw foods whileothers may have anti-cancer effects or act asmediators for targeted drug delivery.8 9 10 11 12 13Potential functions of lectins:14 Carbohydrate transport Specific cellular recognition Embryonic development Cohesion Binding of carbohydratesLectins initially drew the attention of researchersbecause of their ability to bind or “agglutinate” redblood cells and were defined as “hemagglutinins”though they are capable of binding a variety of cells.Researchers noted that certain lectins would bindto one type of red blood cell (e.g. type A, B, AB, orO) but not another depending on the saccharideassociated with the specific blood type.17In one study of 88 different foods, 29 foods werefound to agglutinate either human erythrocytes orGlycobiologyGlycobiology is the comprehensive studyof carbohydrates/saccharides and thespecific proteins such as lectins thatrecognize/bind them.3For example,4 Wheat germ agglutinin (WGA)binds to N-acetylglucosamine andits glycosides Concanavalin A from jack beansbinds to mannose, glucose,glycosides of mannose & glucose Peanut agglutinin binds togalactose and galactosides Red kidney bean lectin binds toN-acetylglucosamineThe Latin word legere, meaning tochoose or select, is the basis for the wordlectin.5The term lectin in general refers to “allsugar-specific agglutinins of nonimmuneorigin, irrespective of source and bloodtype specificity.” 6Lectins may bind several cells and create“clumps” or masses of cells that becomestuck together.7

bacteria commonly found on or in humans (e.g. S. mutans, S.sanguis, S. aureus). The clinical significance of these activitieshas yet been well defined.18 Another study points out thatgreater than one-third of beans tested was found to displayhemagglutinating activity. Of those displaying activity, tenpercent exhibited blood type specificity.19Lectins in the NewsDr. Peter D’Adamo’s Eat Right 4 Your Type , also known asthe “blood type diet” is based on the principle that certainlectins bind to certain types of red blood cells.20 The premiseof this eating plan is still considered controversial due to lackof clinical research (as of April 2018) though some individualsmay benefit from following such a plan.21 22Cardiologist Steven Gundry, MD, FACS, FACC addressesdietary lectins in his 2017 book The Plant Paradox: TheHidden Dangers in “Healthy” Foods That Cause Diseaseand Weight Gain23, linking them to a number of disordersincluding obesity, cardiovascular disease, allergies,autoimmune disease, and cancer. The book provides specificlists of foods to include or avoid along with recipes, mealplans, and modifications for ketogenic, vegetarian, andvegan plans.24 Dr. Gundry has been conducting researchinto the effects of a low-lectin diet (combined with othernutrition interventions) on risk of cardiometabolic disease,autoimmunity, and other disorders. 25 26 27 28 29 Practitionersshould watch closely for confirmation and conclusions thatmay come from that research.A paleolithic or “paleo” eating plan also advocates eliminatinglectin-containing foods.30At this time, some nutrition experts suggest that the benefitsof eating healthy foods that contain lectins outweighpotential negative effects as long as adequate soaking,cooking, or processing is utilized to deactivate lectins.31 32Bean concentrates such as Phaseolus vulgaris from whitekidney bean have been commercially marketed as “starchblockers” and weight loss aides as they essentially induce“starch malabsorption.” 33 34 While some research suggeststhey may have a role in weight management, a 2011 metaanalysis finds the research available on “starch blockers” tobe inconclusive.35Ricin has been in the news when used in its purified formto poison people. Ricin is a toxic lectin derived from castorseeds but is not considered a dietary source of lectins.36The CDC emphasizes that “castor beans are processedthroughout the world to make castor oil it would take adeliberate act to make ricin and use it to poison people.37Biological processes mediatedby endogenous mammalianlectins15 Cell-cell self recognition Cell-extracellular matrix(ECM) interactions Gamete fertilization Embryonic development Cell growth, differentiation,signaling, adhesion, andmigration Apoptosis Immunomodulation andinflammation Host-pathogen interactions Glycoprotein folding androuting Mitogenic induction HomeostasisImmune-related functions oflectins Defense against invadingpathogens Directly kill microorganismsas part of innate immunity Aid dendritic cell andmacrophage phagocytosisof invading pathogens Direct and Indirectinvolvement in adaptiveimmunityAnti-cancer properties oflectins (under investigation)16In vitro, in vivo, and human casestudies demonstrate that certainlectins can Bind to cancer cells Agglutinate cancer cells Have cytotoxic effects incancer cells Inhibit tumor growth Trigger cell death Inhibit angiogenesis

Sources of Plant LectinsLectins are found in most plants including wheat, corn, tomato, peanut, kidney bean, banana,pea, lentil, soybean, mushroom, rice, and potato.38 39 However, lectins are found in the greatestconcentration in raw beans and grains (especially wheat), followed by dairy, seafood, and plants inthe nightshade family (e.g. tomato, potato, eggplant, bell pepper).40 Wheat germ agglutinin (WGA) isconsidered the most common food lectin consumed. 41Lectins exist primarily in the raw forms of foods. Heating and cooking appears to degrade mostlectins, although pre-soaking beans is most effective at eliminating lectin activity. Dry heat or roastingmay not be as effective at deactivating lectins. 42 43 44 45 46Lectins found in various parts of the plant have distinct biological activities. Some lectins havestrong anti-viral, anti-fungal, and anti-bacterial tsTubersBulbsRhizomesAnticoagulant and antiplatelet properties; coagulant, mitogenic,antibacteria, antifungal, and antitumor activitiesAntifungal and insecticidal activitiesTermiticidal activityAntiviral and apoptosis-inducing activitiesAntiviral, antibacterial and antifungal activitiesMitogenic and antiviral activitiesAntifungal and termicidal activitiesInsecticidal and antitumor activitiesProteolytc activitiesAntiproliferative, immuno-stimulatory, antiviral, antifungal,antitumor and apoptosis-inducing activitiesReducing Lectin ContentLectins may be deactivated using different methods including dry roasting, toasting, autoclaving,microwaving, and infrared heat. However, lectins in some foods such as beans may be heat stableand are best deactivated via aqueous heat. This method requires initial soaking in water for at least 8hours followed by cooking in water at high heat (212’ Fahrenheit/100’ Celsius) for at least 10 minutesor at 203’F/95’ Celsius for 60 minutes. This method may not be effective with other lectins suchas wheat germ agglutinin, gluten-associated lectins, and taro tuber lectins and further prolongedheating may be required. Lectins may also be resistant to breakdown by digestive enzymes thoughappropriate heat treatment may denature them enough to increase their digestibility. 48Slow cooking may not get hot enough and may not deactivate kidney bean lectins. It is best to soakkidney beans (and other legumes) for at least 5 hours, discard soaking water, and boil the beans forat least 30 minutes.49Sprouting or fermenting foods that are high in lectins in their raw state may also effectively reducelectin activity.50 Lectin content may be reduced by 59% by sprouting (e.g. soybeans)51 and may bereduced by up to 95% by fermenting as is the case with tempeh, a fermented soybean food.52 Historysuggests that traditionally prepared grains were first fermented or sprouted, in effect reducing theirlectin content.53

Recommend aqueous heat to deactivate or destroy legume bean lectins: Soak in water for at least 8 hours, up to 16 hours at 68’F/20’C, discard water Cook in water at high heat (212’ Fahrenheit/100’ Celsius) for at least 10 minutes or at203’F/95’ Celsius for 60 minutes. Discard any beans that remain hard as lectins may not be adequately destroyedWheat germ agglutinin, gluten-associated lectins, and taro tuber lectins require prolonged heatingbeyond that used for beans. 54Cooking and processing appears to minimize or eliminate lectin content in wheat-based products aswell. Some products such as whole wheat pasta may be exposed to adequate heat during processwhich may eliminate lectins completely.55Lectins can be blocked by certain carbohydrates such as simple sugars or oligosaccharides such asN-acetylglucosamine (blocks wheat lectin). 56 One animal study using the endogenous lectin galectin-1downregulated the autoimmune response to beta cells and even reverse hyperglycemia in mice withtype 1 diabetes.57Fig. 26-1.Source: de Punder K, Pruimboom L. The dietary intake of wheat and other cereal grains and their role in inflammation.Nutrients. 2013 Mar 12;5(3):771-87. doi:10.3390/nu5030771. Review. PubMed PMID: 23482055; PubMed Central PMCID:PMC3705319. 19/ Creative Commons license https://creativecommons.org/licenses/by/3.0/

Interesting animal research demonstrated thatco-administration of sucrose with raw kidneybean lectin significantly reduced the lectin’s toxiceffects including increased intestinal permeabilityand bacterial translocation.58 Ongoing researchis exploring the potential benefit of administeringcertain sugars and oligosaccharides concurrentlywith lectin-containing foods to help deactivatethe lectin component.Supplementation with specific carbohydratesmay affect lectin activity as well. Commercialdietary supplements have been formulatedwith a variety of ingredients designed to eitherblock lectin binding, enhance digestion, or helpsupport gastrointestinal microbiota. N-Acetyl Glucosamine Bladderwrack (Fucus vesiculosus) Okra fruit D-Mannose Mucin Sodium Alginate Pepsin Larch Arabinogalactans Methylsulfonylmethane (MSM) Vegetable PeptaseResearchers focused on geneticengineering have proposedtransferring lectin genes into foodcrops due to their insecticidalproperties. However, manyscientists warn against thispractice due to potential negativehealth effects on humans. 5960 61 62Unfortunately, scientistsexpressing concerns associatedwith engineering lectins into foodshave been professionally silencedin the past.63Lectins are not always deactivated ordegraded by heat or digestion.Lectins that appeared to resist proteolyticdigestion included those in wheat germ (wheatgerm agglutinin or WGA), tomatoes, and navybeans although these foods weren’t foundspecifically to bind human erythrocytes. Lectinsin wheat germ, peanuts, and dry cereals doappear to possess hemagglutinating activity.64One study revealed that peanut lectin wasdetected in blood samples after individualsconsumed either raw or roasted peanuts,suggesting that digestive activity and heatby roasting do not always destroy lectins,particularly those in peanuts.65 Cell researchhypothesizes that circulating peanut agglutinin(PNA) may have the ability to mimic endogenousgalactin-3 and promote cancer cell metastasis.However, considering the study used highdoses of PNA applied directly to cancer cells, theresearch may not be relevant to humans, thoughthe premise does warrant further monitoring.66On the other hand, peanut agglutinin may play arole in detecting cancer cells through its bindingcapabilities. One study points out that PNA wasfound to bind to colon mucins (glycoproteinconstituents of mucus) in cancerous but notnormal cancer cells.67 It appears the tendencyof PNA to bind GI cancer cells is being employedin the area of cancer diagnostics.68 Lectinhistochemistry may also be used in a diagnosticcapacity to help reveal dysplastic changes ingastric mucosa.69Most research suggests thatlectins can be “deactivated” ordegraded by adequately cookingand/or soaking and cooking foodshigh in lectins.70 Plant lectins arefound to be more resistant tobreakdown by heat and digestionthan animal-derived lectins.71Concerns have been raisedregarding ingestion of lectinsbecause of their ability to bindbiological molecules that containcarbohydrate moieties (e.g.red blood cells, mucosal cells).Because some lectins are resistantto breakdown, some researchersrecommend minimizing theirintake all together.72

What health benefits or concerns are associated with lectins?Lectins in their active state have the potential to disrupt cell physiology and function and may bereferred to as “anti-nutrients.” They must be deactivated prior to consumption or degraded bydigestion to be consumed safely. Lectins may be endocytosed (engulfed) by gut epithelial cells whichmay trigger detrimental effects due to their binding to the wall of the intestine.73 74According to a toxicology review in the early 2000s, lectins in their active, binding state have thepotential to75 Bind to membrane glycosyl groups of cells lining the digestive tract Affect turnover and loss of gut epithelial cells Damage the luminal membranes of the epithelium Interfere with nutrient digestion and absorption Stimulate shifts in GI bacterial flora Modulate the immune state of the digestive tract Systematically disrupt lipid, carbohydrate, and protein metabolism Promote enlargement and/or atrophy of key internal organs and tissues Alter hormonal and immunological status May threaten growth and health of animals consuming them in large amounts Are detrimental to numerous insect pests of crop plantsRemember these detrimental effects refer to active lectins that are not broken down or degraded.Adverse Reactions to LectinsIt is still not clear exactly what the health risks of lectins in the food supply are or what their exacteffects on human cells may be.Acute reactions to lectin consumption (e.g. undercooked kidney beans) include nausea, vomiting,diarrhea, and general gastroenteritis. 76 77 78Researchers propose that lectins interfere with repair mechanisms at the level of the gut epithelialcells, leading to observed gastrointestinal symptoms.79Potential gut-specific adverse effects of lectins if eaten in large quantities80 81 82 83 Affect turnover and loss of epithelial cells Damage luminal membranes of the epithelium Interfere with digestive/absorptive activities Acute nausea, vomiting, diarrhea Stimulate shifts in bacterial flora Modulate the immune state of the digestive tract Interfere with gut hormone secretion Serve as potent growth factors for the small intestine (e.g. hyperplasia, hypertrophy) Some effects may be beneficial though human research is scarceSome suspect that reported adverse reactions to foods in the nightshade family (e.g. tomatoes,potatoes, eggplant, bell pepper) may be due to the presence of lectins. 84 85Some research has extrapolated lectins’ affinity for specific carbohydrates to corresponding tissue,suggesting the potential for related adverse reactions. 86

Lectins/Agglutinins with affinity to specific **Stomach***Parietal cellsIntestinalbrush glutinins**ThyroidSkeletalmuscleCardiacmusclePea Lectin**************Pituitary******Eye*Brain (myelin)*******Fig. 26-2.WGA, wheat germ agglutinin; SBA, soybean agglutinin; PNA, peanut agglutinin; LA, lentil agglutinin; MA, mushroom agglutinin;TA, tomato agglutinin; PA, pea agglutinin; POT.A, potato agglutinin; KBA, kidney bean agglutinin; JBA, jack bean agglutinin.Adapted from: Lambert J, Vojdani A (2017) Correlation of Tissue Antibodies and Food Immune Reactivity in Randomly SelectedPatient Specimens. J Clin Cell Immunol 8: 521. doi: 10.4172/2155-9899.1000521.

Lectins and DiseaseWhat does the science say?A causative link between dietary lectinconsumption and specific diseases has notbeen established except for the knowntoxicity caused by consuming uncooked orundercooked kidney beans and possibly otherdried beans.Extensive, conclusive research is not yetavailable to determine the exact effects ofdietary lectins within the body and whetherthey cause chronic inflammation, autoimmunedisorders, gastrointestinal damage,cardiometabolic disease, or other chronicdiseases. Early research suggests that lectinsmay indeed influence these conditions if notcompletely deactivated or destroyed prior toconsumption.Potential concerns include87 Anemia Autoimmune reactions Binding of erythrocytes and lymphocytes Disruption of GI microbiota Immune reactivity Individual susceptibility due to enzymedeficiency (e.g. G6PD deficiency) Inflammatory response Intestinal damage with resulting nutrientdeficiencies Tissue binding and disruptionAnimal research has demonstrated that effectsof lectin consumption on the small intestineand stomach included88 Stripping of mucous coat Overgrowth of abnormal bacteria andprotozoa Increased release of gastric histamine Theoretical increased risk of H. pyloriinfectionResearch and observation in the 1990s notesthat wheat gliadin is a “lectin-like” substanceand its binding to GI mucosa may contribute toceliac pathophysiology. Research also revealedthat wheat lectin binds to tissues in the humankidney (glomerular capillary walls, mesangialcells, and tubules), and binds IgA antibodiesin rodents. Researchers surmise that humanIgA nephropathy may be linked to wheat lectinand noted that elimination of wheat gluten inchildren with this disease resulted in a decreasein proteinuria and immune complex levels.89Current research published in 2017 suggeststhat plant lectins represent “danger molecules”and are capable of activating the NLRP3inflammasome, promoting inflammation andmitochondrial damage. This evolving researchshould help define any potential role thatdietary lectins may play in disorders such asinflammatory bowel disease, insulin-dependentdiabetes, rheumatoid arthritis, and food allergy,intolerance, and sensitivity. 90The innate immune system recognizes “danger molecules” and mounts aninflammatory immune response to them via protein complexes known asinflammasomes. The inflammasome is then responsible for the release ofproinflammatory cytokines which in turn may underlie common inflammatorydisorders including Alzheimer’s, arthritis, atherosclerosis, gout, and diabetes.Developing research suggests ingestion of plant lectins may be a trigger for suchinflammatory diseases. 91

Increased IntestinalPermeabilityResearch demonstratesthat WGA can increaseintestinal permeability.92Researchers theorize thatan increase in intestinalpermeability will increasepassage of potentiallyharmful compounds suchas bacterial toxins or lectinsthemselves may triggersystemic inflammation andother adverse effects.Fig. 9-5. IntestinalPermeabilityartist’s renditionartist: ThomasSextonThomas.d.sexton@gmail.comNote increasedpassage ofelements whentight junctions arecompromisedAutoimmunitySome researchers suggest that the cascade of events following increased intestinal permeability maybe directly related to autoimmune disorders if harmful antibodies are formed and react or crossreact with tissues in the body.93 Increased intestinal permeability caused by WGA may contribute tothe pathophysiology of celiac disease. It was observed that celiac patients had higher antibodies toWGA than healthy individuals did. 94The proposed link between lectinsand autoimmune reactions may lie instimulation of class II HLA antigens intissues such as thyroid and pancreaticislet cells. Research suggests thatcytotoxic antibodies associated withinsulin-dependent diabetes bind adisaccharide (N-acetyl lactosamine) thatalso binds tomato, potato, wheat, andpeanut lectins, possibly contributing toautoimmune attack of the islet cells.95A link to rheumatoid arthritis may berelated to an abnormal IgG moleculethat exposes N-acetylglucosamine towhich certain lectins can bind (e.g.wheat lectin). Indeed, wheat ingestionappears to be a trigger for some withrheumatoid arthritis. Provision ofexogenous N-acetylglucosamine mayhelp to block lectin interaction andreduce symptoms. 96Fig. 26-3. Source: Lambert, J, & Vojdani, A. (2017). Correlation oftissue Antibodies and Food Immune Reactivity in Random SelectedPatient Specimens. Journal of Clinical & Cellular Immunology, 8(5).doi:10.4172/2155-9899.1000521. 156b14c8b108cd9af31a4e.pdf CreativeCommons LicenseIndividual differences may determinewhether exposure to lectins leads toadverse effects. 97 For example, lectinsmay only affect and cause rheumatoidsymptoms in those with a geneticpropensity for rheumatoid arthritis.98

Dr. Gundry Research Abstracts99 100 101 102103Some of the most intriguing human subjectsresearch on lectins appears to be done bycardiologist Dr. Steven R. Gundry who hasconducted trials and published abstracts invarious cardiology journals. Although the studyprotocols incorporated different variablesincluding specific nutritional supplementation,incorporation of anti-inflammatory foods, andprovision of pre- and probiotics, Dr. Gundryemphasizes that restriction of lectins is acornerstone underlying observed benefits.new event rate per 5-year period in patientsfollowing standard treatment protocols (lowfat/cholesterol diet, exercise, lipid-loweringmedications). Patients on the study protocolwere followed for an average of 4.5 yearsduring which only 0.5% received a new stent;no patients had an MI or unstable angina, andCorus scores decreased significantly in 92% ofpatients. (Corus measures likelihood of havingobstructive coronary artery disease.)105Frequently Asked QuestionsShould everyone avoid lectins?One study looked at the premise thatautoimmunity is related to dysbiosis, increasedintestinal permeability, and lectin exposure.The study included 102 patients with markersof epithelial inflammation, autoimmune diseaseactivity, and signs/symptoms of autoimmunediseases including inflammatory bowel disease,rheumatoid arthritis, Sjogren’s, and scleroderma.Biomarkers included adiponectin, hs-CRP, TNFalpha, IL-6, fibrinogen, and myeloperoxidase.It is certainly important to avoid lectins in theiractive form (mostly in the raw form of foodsthat are naturally high in lectins). However, thequestion of whether it’s detrimental to consumethose foods after they have been soaked,cooked, or processed would depend on if lectinswere adequately deactivated or destroyed. Itis possible that some individuals may be moresensitive to lectins or more prone to negativeeffects from their inadvertent ingestion.The study protocol eliminated major dietarylectins (all grains, pseudo grains, beans/legumes, peanuts, cashews, nightshades,squashes, and casein A1 cow’s milk products)and supplemented with prebiotics, probiotics,and polyphenols. Within 9 months, autoimmuneand inflammatory markers were completelyresolved in 95 of 102 patients and demonstratedimprovement in biomarkers in the remaining 7patients.104Who would benefit from a low-lectin diet?Another study looked at implementation of alectin-restricted diet combined with targetednutrition supplementation in 800 patientswith known coronary artery disease. The studyprotocol included restriction of high-lectinfoods (grains, legumes/beans, nightshades,seeded vegetables, casein A1 milk), fruits, andcommercial poultry. Patients with an Apo Egenotype were instructed to eliminate animalfats and cheeses. Intake was supplementedwith one liter/week of olive oil, large amounts ofgreen vegetables, polyphenol-rich coffee or tea,1 ounce/day dark chocolate, 4000 mg high DHAfish oil, 200 mg grape seed extract, and 25 mgpycnogenol daily.Results were compared to an average 30-40%Even though cooking and processing is foundto destroy/deactivate most lectins, a low-lectintrial should remove those foods naturally high inlectins to avoid unintentional ingestion.A low-lectin approach would ideally eliminatethose foods highest in lectins during the trialphase as it would be nearly impossible to avoidall lectins in all foods. Individuals suspected ofbeing sensitive to lectins may be able to tolerateincorporation of those foods once they havebeen treated adequately with soaking, boiling,fermenting, or sprouting.Can we remove lectins from the foods we eat?Foods that contain lectins in their raw state canstill be considered healthy foods as long as theyare heated, fermented, or processed enoughto remove potentially harmful lectins. Nutritionprofessionals give the “go ahead” on thesecommonly consumed foods (as long as lectinsare adequately eliminated):106 Peanuts (difficult to eliminate lectins buthealth benefits believed to outweigh lectinrisk)

Potatoes (although up to 50% of lectinsmay remain following heating, no definitiveresearch demonstrates negative effectsfrom consuming potato lectins) Red kidney beans and other dried beans(thoroughly soaked and cooked) Soybeans (must be fermented (e.g. soysauce, miso, tempeh), sprouted, or boiled at212’F for at least 10 minutes) Tomatoes Wheat/wheat germ (adequately cookedat 149’F or above during cooking orprocessing)Is there testing available for lectin sensitivity?Though there are no specific tests for lectinsensitivity, eliminating and then reintroducingfoods highest in lectins may help determine if anindividual is sensitive. Testing immune reactionsto foods that contain lectins may also helpnarrow down which foods an individual may trulybe sensitive to.Do all healthcare practitioners agree on theeffects of lectins on the body?Here we have more confusion as not all nutritionprofessionals or healthcare practitioners agreeon the role that lectins may play in health anddisease. Some physicians such as Steven GundryM.D. express concerns and feel confident thatlectins in foods are associated with an increasedrisk of disease and should be eliminated bymost. At the opposite end of the spectrum,Michael Greger, M.D., refutes and actuallydismisses Dr. Gundry’s premise. Dr. Gregeremphasizes that a number of studies associateconsumption of foods such as dried beansand whole grains with a lower risk of chronicdisease.107 (Note that dried beans and grainsare always consumed cooked so lectin levels inthese studies are likely low.)What questions remain?Do well-cooked foods still contain lectins?There appears to be a possibility that somelectins resist heating and digestion and mayenter the bloodstream. It is unclear whether thislevel of lectin exposure poses any health risksDo lectins definitively cause disease?The question of whether lectins cause diseasein humans continues to be researched anddebated. Unfortunately, there are no largescale clinical trials to fully answer that question.Researchers are proposing a variety ofhypotheses related to the effects of lectins at thecellular and tissue level.The Bottom LineIt can be hard to sort through what is conclusiveresearch and what is hyperbole when it comesto what effects lectins may have on humanphysiology.In general, it is accepted that lectins in theiractive form can bind carbohydrate moietieson human cells and cause agglutination. It isalso accepted that if lectins are degraded ordeactivated (proper cooking or via digestion)they will not be able to cause adverse reactions.Until further research is done to specificallydemonstrate that ingestion of dietary lectinsdefinitively causes inflammation, autoimmunity,or gastrointestinal damage, individual sensitivityto lectins may need to be explored on a trial/challenge basis.Small amounts of lectins may be tolerated bysome individuals. However, it is prudent to soak,heat, or treat high-lectin foods adequately tominimize lectin activity. Using a pressure cookermay also reduce lectin activity.Individuals who do suffer from chronicinflammation, gastrointestinal disorders,or autoimmune disease may benefit fromelimination of foods high in lectins. A controlledreintroduction should help determine if lectincontaining foods trigger symptoms.It is important to note that many individualsconsume grains and legumes (high lectin foods)on a regular basis (e.g. the Mediterranean diet)and don’t appear to suffer detrimental effects.However, dried beans are most often soakedand boiled and grains are usually consumedafter cooking at fairly high temperature soit’s possible that lectin levels are reduced inthose foods. Individual sensitivity to lectins maydepend on genetic makeup or other biochemicalor physiological differences.

TakeawaysIt is essential that high-lectin foods are soaked,cooked, heated or processed adequately toeliminate or minimize lectin activit

to poison people. Ricin is a toxic lectin derived from castor seeds but is not considered a dietary source of lectins.36 The CDC emphasizes that “castor beans are processed throughout the world to make castor oil it would take a deliberate act to make ricin and use it to poison peop

Related Documents:

brought about the popularity of a variety of "low-lectin diet plans." Translated into the foods on your plate, lowering lectins. according to these plans means, avoiding wheat, rice, corn, potatoes, all beans; and to instead to obtaining daily calories from the two major categories of food poisons: animals and vegetable oils. The ultimate outcome of asking people to seek health by "lectin .

of the cell and eventually divides into two daughter cells is termed cell cycle. Cell cycle includes three processes cell division, DNA replication and cell growth in coordinated way. Duration of cell cycle can vary from organism to organism and also from cell type to cell type. (e.g., in Yeast cell cycle is of 90 minutes, in human 24 hrs.)

UNIT-V:CELL STRUCTURE AND FUNCTION: 9. Cell- The Unit of Life: Cell- Cell theory and cell as the basic unit of life- overview of the cell. Prokaryotic and Eukoryotic cells, Ultra Structure of Plant cell (structure in detail and functions in brief), Cell membrane, Cell wall, Cell organelles: Endoplasmic reticulum, Mitochondria, Plastids,

The Cell Cycle The cell cycle is the series of events in the growth and division of a cell. In the prokaryotic cell cycle, the cell grows, duplicates its DNA, and divides by pinching in the cell membrane. The eukaryotic cell cycle has four stages (the first three of which are referred to as interphase): In the G 1 phase, the cell grows.

Many scientists contributed to the cell theory. The cell theory grew out of the work of many scientists and improvements in the . CELL STRUCTURE AND FUNCTION CHART PLANT CELL ANIMAL CELL . 1. Cell Wall . Quiz of the cell Know all organelles found in a prokaryotic cell

Stent Type Stent Design Free Cell Area (mm2) Wallstent Closed cell 1.08 Xact Closed cell 2.74 Neuroguard Closed cell 3.5 Nexstent Closed cell 4.7 Precise Open cell 5.89 Protégé Open cell 20.71 Acculink Open cell 11.48 Stent Free Cell Area Neuroguard IEP Carotid Stent

Stent Type Stent Design Free Cell Area (mm2) Wallstent Closed cell 1.08 Xact Closed cell 2.74 Neuroguard Closed cell 3.5 Nexstent Closed cell 4.7 Precise Open cell 5.89 Protégé Open cell 20.71 Acculink Open cell 11.48 Neuroguard IEP Carotid Stent Stent Free Cell Area

AutoCAD 2000, 2000i & 2002 System Variables Highlighted numbers are preferred or standard Variables pertain to all versions except where noted (200XX) System Variable Command(s) affected _PKSER Environment (Read-only) Type: Integer Saved in: Registry Returns the serial number assigned to AutoCAD ACADLSPASDOC TOOLS/OPTIONS Type: Integer Saved in: Registry Initial value: 0 Controls whether .