I bought "The Plant Paradox" because I found some useful information on Dr. Gundry's website - he says that pressure-cooking some foods is a good idea, because it can destroy a lot of their lectins. I'd been having diarrhea from quinoa for years - and I found that if I pressure-cooked it for a long time - no more diarrhea! Which could be lectin-related or not. And there have been studies showing that pressure-cooking or autoclaving food at least partially destroys some food allergens and may help in building tolerance.
So I thought, maybe there are more good ideas in his book.
There are many special diets around, and many people claim wonderful things for them.
But caloric restriction is anti-inflammatory, and a lot of people would eat fewer calories on Dr. Gundry's diet, because it eliminates so many common foods, because it gets people to pay attention to what they're eating, and because he recommends intermittent fasting. So it's not surprising that he would see anti-inflammatory effects in many patients.
Also, there's lots of research that shows it's possible for people to have food hypersensitivities that don't show up in standard skin or blood tests for food allergy. And many people who have these food hypersensitivities don't know about them.
So when people say they were helped by Dr. Gundry's diet, maybe it's because it excludes many grains and legumes and a great many other allergenic foods, and they've developed hypersensitivities to some of those foods. Or maybe it's because they have a gluten intolerance - the diet is gluten-free.
Do dietary lectins cause disease? Lectins are proteins or glycoproteins that bind to carbohydrates. They may be specific for a particular carbohydrate/sugar molecule. Lectins can be both harmful and beneficial. In large quantities, some lectins are obviously harmful - e.g., raw beans are poisonous. But Dr. Gundry thinks that lower lectin doses, which are generally considered to be safe, can cause serious harm long-term, in concert with other novel features of the modern environment such as antibiotics and various chemicals -- causing the modern increase in allergies and autoimmune diseases and our obesity epidemic, among other things.
Some lectins have anti-cancer properties - but at the same time, this means they are powerful substances that might also cause harm, as Dr. Gundry proposes.
Along with the low-lectins diet, there are a melange of other ideas. He thinks that various commonly used chemicals can cause serious harm; for example, he recommends that people handle receipts printed on thermal paper with tongs, to avoid touching them, because they might contain BPA. He's anti-GMO. He's anti-sugar to the extent of being anti-fruit (because of the fructose in fruit). And anti-animal protein. And in favor of intermittent fasting.
He promotes a "ketogenic Plant Paradox diet" as especially healthy. It includes starchy foods like sweet potatoes, taro root and millet - I suppose those would have to be limited to induce ketosis. He makes many extravagant claims for its benefits, but I didn't get into fact-checking them.
He talks a lot about eating in the way that we are adapted to by evolution. He says that grains and pseudo-grains tend to have more lectins that interfere with people's health because they are seeds, and plants have evolved to protect their seeds. So, except for fruits, which are designed to be eaten, many seeds have noxious stuff in them.
There are many false statements in the book. He exaggerates a lot. There's a kernel of truth in a lot of what he says, although some things are completely wrong. He says a lot of things without giving references, and the references he gives often don't support what he says. He misrepresents most of the studies in his list of references, to make them sound like they support his claims, when they actually don't. And he extrapolates from a kernel of truth to make big claims. So don't take his word for anything!
There's a long section of fact-checking various claims at the end of this review. Most of his claims do not check out.
He has done some presentations on his lectins hypothesis at medical conferences.
He did a trial on 1000 people, which was presented at an American Heart Assoc. conference. 800 of them had either an autoimmune disease themselves or a family member with an autoimmune disease. They were asked to eat his diet, which "consisted of avoidance of grains, sprouted grains, pseudo-grains, beans and legumes, soy, peanuts, cashews, nightshades, melons and squashes, and non-Southern European cow milk products (Casein A1), and grain and/or bean fed animals.", and adiponectin and TNF-alpha levels were measured every 3 months.
Their levels of TNF-alpha normalized within 6 months, but the adiponectin levels remained elevated.
So he concluded that "TNF-alpha can be used as a marker for gluten/lectin exposure in sensitive individuals."
But he doesn't say how those 1000 people were selected. Maybe they were cherry-picked to show a good result.
And, he didn't have a control group. A control group might consist of people eating his Plant Paradox diet, but also taking a capsule with wheat germ agglutinin (wheat lectin), so that they would be getting the same amount of lectins that people eating the average American diet do. And there would also be a test group, of people eating his Plant Paradox diet and taking a capsule with placebo. That would test whether WGA actually has the effects that he thinks it does.
Also, he presented at conferences:
Also, he presented at conferences:
Even though he's had these supposedly great results, Dr. Gundry has published no research that appears on Medline (the peer-reviewed medical journals) about his lectins hypothesis. And the extent to which he distorts science in The Plant Paradox suggests that his presentations at conferences might involve similar distortions.
There's some suggestive research on Medline (see below), but mostly the evidence for his views about lectin-avoidance boils down to his clinical experience. Try it if you like and see if it helps, but I wouldn't take it as a rigid prescription for good health. It is certainly not authoritative or evidence-based, and following his instructions in detail seems like an invitation to obsessive behavior around food - and also in the rest of one's life, such as his instructions to handle receipts printed on thermal paper with kitchen tongs!
If you're currently eating gluten, it would be a good idea to get tested for celiac disease before starting his diet. Also see Six Reasons to Test for Celiac Disease Before Starting a Gluten Free Diet.
Many of the people reading this book are likely primarily interested in weight loss, and a lot of it is oriented towards weight loss. But there's no reason to believe his diet is especially good for that. The National Weight Control Registryfollows people who have lost a lot of weight and managed to keep it off for a long time. They found that these people initially lost the weight in a wide variety of ways - low-carb, low-fat, etc. etc. But they generally kept it off with a lowfat diet. Dr. Gundry's diet tends to be high-fat (although it does include some starchy foods), so it's probably not very good for maintaining a weight loss.
So here's the fact-checking section. I didn't fact-check everything he said. If something he says doesn't appear here, that doesn't mean it's true! And some of his statements do check out.
There is evidence that dietary lectins might affect the immune system, such as:
Potato lectin activates basophils and mast cells of atopic subjects by its interaction with core chitobiose of cell-bound non-specific immunoglobulin E They found that potato lectin caused histamine release in blood drawn from most of the atopic people they tested, even though many of them didn't test positive to it with the skin prick test.
You've probably never heard of lectins, but you are definitely familiar with gluten, which is just one lectin among thousands.
Gluten, which is the water-insoluble part of the wheat protein, isn't usually considered a lectin. See Studies on the aetiology of coeliac disease: No evidence for lectin-like components in wheat gluten.
On fruit that was harvested while unripe, he says:
ethylene oxide exposure changes the color to make the fruit appear to be ripe and ready to eat, but the lectin content remains high ... because the fruit never got the message from the parent plant to reduce the lectin content
It's ethylene, not ethylene oxide, that's used to ripen fruit. Plants generate ethylene themselves as a ripening hormone. Is it true that the lectin content is higher in fruit that's been ripened with ethylene after harvesting? He doesn't give a reference for this, and I didn't find evidence either way.
Even if he's right that fruit that was harvested when unripe has more lectins, one could just eat frozen fruit. Frozen fruits and vegetables are harvested after they've ripened.
He thinks that lectins in what an animal eats end up in their meat in significant quantities, so people shouldn't eat grain-fed meat. He doesn't give any references for this, and there's no evidence for it so far as I know.
Lectins ... can interrupt messaging between cells and otherwise cause toxic or inflammatory reactions .
The reference he gives is an article called "Lectin Lock: Natural Defense Against a Hidden Cause of Digestive Concerns and Weight Gain", which is promotional material for the "Lectin Lock" supplement!
The longer you have been eating particular plant lectins, the longer you have been producing gut bacteria specifically designed to defuse them.
The reference he gives is a study called Effects of a gluten-free diet on gut microbiota and immune function in healthy adult humans. The author fed 10 healthy people a gluten-free diet, and found their gut bacteria changed in an unhealthy direction: fewer Bifidobacteria and Lactobacilli, and more potentially unhealthy bacteria. She attributed this to lower intake of polysaccharides (fiber, resistant starch) in the gluten-free diet, which feed the good bacteria. A different study did find that lactobacilli could bind wheat germ agglutinin, a wheat lectin, thus "defusing" it. But there's no indication that particular plant lectins tend to encourage gut bacteria that can defuse them.
Lectins are relatively large proteins. If all is well with your gut health and its mucous layers, lectins should not be able to squeeze past the mucosal cells. ... lectins attack your mucosal wall (so they can get into the bloodstream).
The reference he gives for this is Potato Glycoalkaloids Adversely Affect Intestinal Permeability and Aggravate Inflammatory Bowel Disease. But this paper is about the potato glycoalkaloids, solanine and chaconine, which aren't lectins!
It is now time to reveal which sugar molecule the WGA and other lectins are after ... there's a particular ... lectin-binding sugar, called Neu5AC, [that] sits on the lining of blood vessels and the absorptive cells on the gut wall called enterocytes. Most mammals have a sugar molecule called Neu5GC on the lining of their gut wall and blood vessel walls. But humans lost the ability to make this molecule ... Instead, we make the lectin-binding Neu5AC ... Lectins, and particularly grain lectins, bind to Neu5AC but cannot bind to Neu5GC ... This explains why captive chimps eating a human grain-based diet don't get atherosclerosis ... the chimps lack the lectin-binding sugar molecule.
He doesn't give a reference for this, and it isn't true. Actually, mammals in general have both Neu5AC and Neu5GC. There's an enzyme called SMAH that converts some of the Neu5AC into Neu5GC. But Neu5AC is the predominant sialic acid found in mammalian cells. In humans, SMAH doesn't work because a mutation inactivated it. Chimps do have Neu5AC. WGA (wheat germ agglutinin) does bind Neu5AC. But many other lectins don't; they bind other kinds of sugar molecules instead.
Cattle, pigs and sheep all carry Neu5GC, which your immune system recognizes as foreign when you eat their meat... Neu5GC looks a lot like Neu5AC ... There is significant data suggesting that when our immune system is exposed to ... Neu5GC from red meat, we develop an antibody to the lining of our own blood vessels, which has Neu5AC ... calling in a full-fledged attack from our immune system. ... it has been shown that cancer cells use Neu5GC to attract blood vessel growth toward them, via production of a hormone called ... VEGF. VEGF production is promoted by an immune attack on Neu5GC. Cancer cells even use Neu5GC to hide from our immune cells ... human tumors contain large amounts of Neu5GC.
He doesn't give a reference for this, but an FAQ by Ajit Varki, the main researcher on Neu5GC, states "Neu5Gc tends to accumulate in some cancers. Some cancers are increased in incidence in people who eat red meat. Neu5Gc is enriched in red meat. These are just associations right now - no proof at this time that these findings are directly connected to each other." Similarly he says "it is very hard to tell" which inflammatory diseases Neu5GC might contribute to. He says "Diseases associated with high red meat consumption are certain kinds of cancers, and heart disease. There is some claim that autoimmune diseases like Rheumatoid arthritis benefit from a vegetarian diet, but this is controversial." His advice is "Eat red meat and milk products in moderation - or not at all, if you can get the necessary nutrition from other sources. ... it is already recognized that a prudent and healthy diet should not have an excess of red meat in it."
The lectin WGA (wheat germ agglutinin) ... can attach to the insulin docking port as if it were the actual insulin molecule, but unlike the real hormone, it never lets go - with devastating results, including reduced muscle mass, starved brain and nerve cells, and plenty of fat.
His reference for this is Effects of wheat germ agglutinin on insulin binding and insulin sensitivity of fat cells. I didn't see the full paper, but from the abstract, this was an in vitro study where WGA actually increased insulin sensitivity at low concentrations, but decreased it at high concentrations. I couldn't find evidence from other studies that the actual blood concentrations of WGA that someone might get from their diet, could affect insulin sensitivity. I did find some evidence that increased intake of whole grains vs refined grains (and whole grains have more WGA) improves insulin sensitivity - e.g. Effect of whole grains on insulin sensitivity in overweight hyperinsulinemic adults. I even found something about wheat germ supplementation alleviating insulin resistance. Wheat germ has a lot more WGA than other wheat products.
About two thousand years ago, a ... mutation in Northern European cows caused them to make the protein casein A-1 in their milk instead of the normal casein A-2. During digestion, casein A-1 is turned into a lectinlike protein called beta-casomorphin. This protein attaches to the pancreas's insulin-producing cells ... which prompts an immune attack on the pancreas ... This is likely a primary cause of type 1 diabetes
The reference he gives are Milk Intolerance, Beta-Casein and Lactose, which is a review article promoting the hypothesis that A2 milk is better. One of the co-authors is from the A2 Milk Company. Also, the book "Devil in the Milk".
From the 2017 article A1 beta-casein milk protein and other environmental pre-disposing factors for type 1 diabetes, "exposure to A1 β-casein may promote the development of autoantibodies that ultimately contribute to the cascade of events culminating in the development of type 1 diabetes", but this is only a hypothesis at present! The article concludes that "The evidence for milk and, particularly A1 β-casein, as a primary dietary trigger for type 1 diabetes is intriguing although causation remains unproven. " Three of the authors are associated with the A2 Milk Company, so this article may be biased.
A good review article is Impact of Milk Derived β-Casomorphins on Physiological Functions and Trends in Research A Review. Beta-casomorphins have both positive and negative effects.
There was a study on A2 milk which found that "Compared with milk containing only A2 β-casein, the consumption of milk containing both β-casein types was associated with significantly greater [post-dairy digestive distress] symptoms; higher concentrations of inflammation-related biomarkers and β-casomorphin-7; longer gastrointestinal transit times and lower levels of short-chain fatty acids; and increased response time and error rate on the [Subtle Cognitive Impairment Test]". It was funded by the A2 Milk Company, but it was a double-blind randomized trial, on 45 people. It's intriguing, but preliminary.
Lactobacilli, the type of bacteria that thrive on milk sugar (lactose) ...
Lactose may qualify as a prebiotic - for people who don't make enough lactase to digest the lactose before it gets to the colon where most of the bacteria are. If you're lactose tolerant, it likely isn't nourishing your good bacteria.
An avalanche of research proves that instead of aiding in weight loss or weight maintenance, nonnutritive sweeteners actually cause you to gain weight.
But from https://www.hsph.harvard.edu/nutritionsource/healthy-drinks/artificial-sweeteners/, "There is conflicting research surrounding the health benefits of artificially sweetened drinks. Long-term studies show that regular consumption of artificially sweetened beverages reduces the intake of calories and promotes weight loss or maintenance, but other research shows no effect, and some studies even show weight gain. "
That doesn't sound like an avalanche at all.
believe me, emergency room visits for crazy behavior follow full moon cycles
The evidence doesn't bear that out. See http://faculty.washington.edu/chudler/moon.html.
The use of mouthwashes, which kill mouth bacteria as they give you that 'minty clean' breath, dramatically increases blood pressure.
He gives a reference, Physiological role for nitrate-reducing oral bacteria in blood pressure control. This study found that a chlorhexidine-based antiseptic mouthwash increased systolic and diastolic blood pressure by 2-3.5 mm Hg. That doesn't sound dramatic to me. It IS an interesting finding though, and it sounds like a good idea to avoid antiseptic mouthwashes (unless recommended by a dentist).
Roundup bonds with gluten, making it antigenic (capable of inducing an immune response)
His reference for that is a paper by Samsel and Seneff in the pay-to-play journal "Interdisciplinary Toxicology". Pay-to-play journals are bogus journals that charge authors to publish in them, and they accept almost anything that's submitted. And Seneff was only speculating that Roundup bonds with gluten in her paper. She's a computer scientist, not a biochemist, and she publishes all sorts of speculations.
one in four people now has one or more of the dozens of autoimmune diseases.
Claim without a reference. The NIH says 23.5 million in the USA, which is more like 1 in 13.
94 percent of humans carry a preformed antibody to the peanut lectin
The reference is Expression of peanut agglutinin-binding mucin-type glycoprotein in human esophageal squamous cell carcinoma as a marker. But this glycoprotein is an antigen, not an antibody. An antibody is an immunoglobulin. The peanut lectin binds to this glycoprotein that humans make, but this doesn't mean that 94% of people have an inborn immune reaction to peanut lectin.
The lectin in peanut oil produces atherosclerosis in experimental animals ... but when that lectin is removed from the oil, atherosclerosis does not develop.
The reference is Identification of intact peanut lectin in peripheral venous blood. But this paper doesn't say anything about atherosclerosis! It found that peanut lectin appeared in people's blood after they ate about half a pound of peanuts. That does mean that peanut lectin could have systemic effects, though.
The Incas had three detoxification processes to remove the lectins in quinoa. First, they soaked it, then they let it rot (fermented it), and finally they cooked it.
No reference given, but info online does not indicate that the Incas fermented quinoa before cooking it. They might have soaked it or washed it to remove the saponins, but that's different. The Incas did ferment quinoa - to make beer.
fermentation in sourdough kills gluten
The reference given is Highly Efficient Gluten Degradation by Lactobacilli and Fungal Proteases during Food Processing: New Perspectives for Celiac Disease. This was a study where they did manage to make a very low-gluten sourdough, BUT they used a sourdough culture that was specially selected to break down gluten. The sourdough you buy in the store is NOT gluten-free, and it's very irresponsible of Dr. Gundry to suggest that it is. He could kill some poor celiac who believes him and eats sourdough bread.
sprouting legumes ... actually increases lectin content.
He gives a webpage as a reference, but the webpage doesn't say that.
Feeding sprouted beans or grains to lab animals has been shown to cause cancer.
The reference given is not a study on lab animals, it's a study on cell lines in vitro.
A recent study shows that saturated fats such as lard increase hunger and appetite by delivering LPSs [lipopolysaccharides] to the brain's hunger center.
The reference given is a Scientific American article Lard Lesson: Why Fat Lubricates Your Appetite, about a study that found PKC-theta [protein kinase C-theta, which is a protein] was involved in hypothalamic insulin resistance. No mention of LPSs.
meta-analysis shows that cereal grains are actually a negative component of [the Mediterranean diet.
His reference is Mediterranean diet and the incidence of cardiovascular disease: a Spanish cohort. They did indeed find that cereal grains were a negative component, but they said in that population cereal grains were mostly consumed as white bread. And white bread has only small amounts of wheat lectin.
because the lectins in grain bind to joint cartilage, Italians overall have significatly high rates of arthritis.
His reference is Lectin-binding in normal and fibrillated articular cartilage of human patellae. This was an in vitro study which found that lectins bind differently to normal vs arthritic cartilage. It doesn't say that lectins caused the arthritis. And Italy actually has low rates of osteoarthritis compared to most other countries in the EU.
Researchers at St. Louis University, who have followed members of the CR Society International for years - these folks restrict their calories, eating about 20 to 30 percent fewer calories than normal ... despite eating fewer calories, the CR folks had IGF-1 levels ... that were about the same as those of people eating a normal diet. ... The researchers then recruited vegans and measured their IGF-1 levels, only to find them much lower than those of the calorie-restricted group. ... Several CR members were asked to cut their animal protein consumption without changing their total calorie intake. Lo and behold, down went their IGF-1 scores to parallel those of the vegans.
The reference he gives is Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans. The CR people were asked to reduce protein intake, not animal protein intake; and the vegans were consuming a low-protein diet - only 0.76 g per kg of body weight per day, which is probably less protein than the average for a vegan. So what Dr. Gundry said is roughly accurate.
vegan Adventists live the longest, followed by vegetarian Adventists who limit dairy fats. Vegetarian Adventists who do consume dairy come next, and the Adventists who occasionally eat chicken or fish bring up the rear in terms of longevity.
His reference is Vegetarian Dietary Patterns and Mortality in Adventist Health Study 2. But the categories in this study were different. They were, in increasing order of mortality: people who ate plant food and fish; vegans; vegetarians who ate dairy & eggs; people who ate meat (including fish) but not more than once/week; and people who ate meat (including fish) oftener than once/week. So including animal food in the form of fish came out looking healthier than being vegan, in this study.
The risk of developing Alzheimer's correlates directly with the amount of meat consumed.
The reference he gives is Using Multicountry Ecological and Observational Studies to Determine Dietary Risk Factors for Alzheimer's Disease, and it does support what he says. From the abstract, "The most important dietary link to AD appears to be meat consumption, with eggs and high-fat dairy also contributing." But also from the abstract, "Diets high in grains, fruits, vegetables, and fish are associated with reduced risk of AD", which is contrary to his anti-grain, anti-fruit views.
Valter Longo of the Longevity Institute at the University of Southern California has shown that a monthly five-day modified vegan fast of approximately 900 calories gives the same results in terms of IGF-1 and other markers of aging, as does an entire month of a traditional calorie-restricted diet.
His reference is Diet mimicking fasting promotes regeneration and reduces autoimmunity and multiple sclerosis symptoms. This is a study where they studied a ketogenic diet and a fasting mimicking diet on mice. It was a mouse model of multiple sclerosis. They did do a pilot trial on 60 human MS patients, but they didn't measure IGF-1. They measured some liver enzymes, WBC count and lymphocytes. I don't know if Dr. Gundry considers those things to be markers of aging.
Fructose is such a toxin that 60% of it is shunted toward the liver, where it is converted to the form of fat called triglycerides (which causes heart disease) and to uric acid, which raises blood pressure, causes gout, and directly damages your kidneys' filtration system ... fruit is candy, toxic candy.
The reference he gives is Fructose, but not dextrose, accelerates the progression of chronic kidney disease. This was a study on rats where they were fed a diet of 60% fructose (by weight, I think), and it did bad things to their kidneys. And eating a high-sugar diet, as the rats did, is bad for you. But fruit consumption (for humans) is actually associated with lower mortality from all causes. See Fruit and vegetable consumption and mortality from all causes, cardiovascular disease, and cancer: systematic review and dose-response meta-analysis of prospective cohort studies. They said there was a threshold of around five servings of fruit and vegetables a day, after which the risk of all cause mortality did not reduce further. Eating an apple a day seems to be good for you; eating nothing but fruit, probably not.
100 percent of my autoimmune and lectin-intolerant patients ... were vitamin D deficient when they first enrolled ... I consider normal [to be] 70 to 105 ng/ml for serum 25OHD ... if you are just beginning this program, please add just 5000 IUs of vitamin D3 daily. For autoimmune disease, start with 10,000 [IU vitamin D] per day.
He doesn't give a reference for this, but from Dietary Reference Intakes for Calcium and Vitamin D report by the Institute of Medicine, the tolerable upper intake level is 4000 IU vitamin D per day for ages 9 and older. From a summary of this report "The indicators considered ... included hypercalcemia, hypercalciuria, vascular and soft tissue calcification, nephrolithiasis, and ... emerging evidence for a U-shaped relationship for all-cause mortality, cardiovascular disease, selected cancers, falls and fractures." They said there are "emerging concerns about risks at serum 25OHD levels above 50 ng/ml".
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