Meet the Crucifer Family…
Public health officials and nutrition experts love to sing the praises of the virtuous cruciferous vegetable family. We are told that these pungent plants can fight off cancer, strengthen our immune system, and leap tall buildings in a single bound. But could crucifers have a dark side?
The cruciferous veggies (the Brassica family) dominate the produce aisle; many people may not realize how many familiar vegetables belong to this family.
List of Cruciferous Vegetables
- Bok choy
- Brussels sprouts
- Chinese Broccoli
- Chinese cabbage
- Choy sum
- Collard greens
- Mustard Greens
- Mustard Seeds
These mustard family members are notorious for giving off a strong odor that sends children ducking for cover underneath the dinner table. That lovely aroma is due to the presence of sulfur-containing chemicals called “thiocyanates.” These are natural plant defense compounds, designed to protect the plant from potential invaders.
Plants are cunning. If they need us to help them disperse their seeds, they will package the seeds in a colorful, appealing fruit and fill it with the sweet sugars we love to eat. However, they do not want us to eat their stalks, roots, stems, and leaves—the vital body parts that keep the plant alive, so they tend to make those parts bitter. Plants do not want to be eaten any more than animals do, but since they can’t run, growl, bite, or claw at creatures that want to feast upon them, they have evolved, over hundreds of millions of years, some very sophistical chemical weapons to ward off hungry passers-by.
Let’s use broccoli as our signature crucifer, as it is the best-studied. Like all cruciferous veggies, broccoli uses isothiocyanates to protect itself. The one it happens to use is called sulforaphane, which is made this way:
Glucosinolate + Myrosinase (enzyme) = SULFORAPHANE
When broccoli is sitting peacefully in a field (cue the flute solo), it does not contain any sulforaphane. This pungent molecule is so toxic to living cells (including broccoli’s own cells) that the two harmless ingredients needed to make it are stored in separate compartments within broccoli cells. However, if the cells’ defenses are breached—if the vegetable is cut or bruised or if an insect or small animal comes along and bites into its flesh (cue the ominous organ music)—the individual compartments break open, the two ingredients mix together, and POOF! Sulforaphane—a chemical weapon with the power to kill things like insects, bacteria, and worms.
How does sulforaphane kill tiny living creatures, and why should you care?
You should care because sulforaphane can do the very same things to your cells that it does to the cells of the little guys:
- Poisons mitochondria (cell energy generators)
- Inhibits microsomal enzymes in the endoplasmic reticulum (cellular manufacturing and detoxifying centers)
- Generates reactive oxygen species (these are damaging “pro-oxidants”)
- Interferes with thyroid iodine absorption
- Disrupts epithelial barriers (can poke holes in sheets of cells)
- Depletes glutathione levels (the most important antioxidant inside our cells)
All of the above mechanisms explain how sulforaphane can kill small living creatures. In research studies it has also been demonstrated that sulforaphane can kill healthy human cells and can cause cancerous changes in human cells.
It may come as a surprise to you to learn that this sulforaphane is the very same broccoli ingredient that we are told is responsible for the health benefits of broccoli. The reason for these health claims lies in the other things that sulforaphane does in research studies:
- Induces cancer cell apoptosis (causes cancer cells to commit suicide)
- Inhibits angiogenesis (slows new blood vessel formation, which is how cancers grow)
- Induces “phase II enzymes” (fires up human immune system antioxidants)
- Kills bacteria (natural antibiotic)
So, as you can see, sulforaphane is a double-edged sword, capable of killing bacteria and cancer cells, as well as killing healthy cells and even causing cancer. Just like any form of chemotherapy, this compound does not do a very good job of distinguishing between cancerous cells and healthy cells, so collateral damage (friendly fire) may occur.
Why do we only hear about broccoli’s superhero side, and not its villainous dark side? As a psychiatrist and someone who has read far too many nutrition articles, I can confidently say this: when it comes to food and health, believing is seeing. If we believe something is good for us, we only see evidence to support that belief and are almost incapable of seeing evidence to the contrary. The belief that vegetables are good for us comes entirely from epidemiological studies, which are only capable of generating untested theories about food and health. Scientific experiments are then conducted to try to support those beliefs, and the truth is that these experiments yield very mixed results about how broccoli affects us.
Scientists who are aware of the dark side of crucifers defend them as superfoods by invoking the concept of hormesis. The hormesis theory essentially says that small amounts of toxic compounds can actually be good for you—this is the “what does not kill you makes you stronger” argument. However, when it comes to crucifers and health, this is just a hypothesis. What’s more, even if it were true, then the best advice about crucifers would be to eat them in small amounts to ensure tiny doses of isothiocyanates. Instead, the prevailing wisdom about crucifers is: the more, the merrier.
- Sprouts contain 20 to 100 times more glucosinolate than mature vegetables (to protect the baby plant).
- Freezing crucifers or boiling them for 10 minutes reduces glucosinolate concentrations by about 50%.
- Steaming reduces glucosinolate concentrations by about 2/3.
- Heat completely destroys myrosinase. However, the bacteria in our gastrointestinal tract contain enzymes that mimic myrosinase, so sulforaphane will still be generated in the process of digestion.
- About 75% of all sulforaphane in the digestive tract is absorbed into the bloodstream and taken up by cells throughout the body. Blood levels peak about 2 hours after eating crucifers.
- Once inside cells, our own natural cellular antioxidant, glutathione, rapidly binds to sulforaphane and escorts it out of cells to be eliminated within 3 hours.
Some scientists have postulated that our cells get rid of sulforaphane as quickly as possible precisely because it is an unwanted guest–an irritant, rather than a helpful tool in our cancer-fighting arsenal.
So, is broccoli good for you?
We really don’t know. I was unable to find any convincing clinical evidence to support the health benefits of crucifers, but I did find enough interesting scientific evidence to at least call their health benefits into question. Most humans and their ancestors have been eating vegetables for tens if not hundreds of thousands of years. Therefore, even if broccoli may be potentially harmful to us, we have likely evolved ways to minimize any damage it may cause. Case in point: although we do absorb significant amounts of sulforaphane, our cells rapidly evict it. However, individuals with chemical sensitivities, weakened immune systems, liver disease, and /or gastrointestinal problems may be more likely to experience symptoms related to the natural chemicals in certain vegetables, which are usually not suspected as potential culprits. People with hypothyroidism (under-active thyroid) may also want to consider removing cruciferous vegetables due to their potential to interfere with normal thyroid activity.
Are children who hate broccoli onto something? Out of the mouths of babes…
Source: Article by Georgia Ede MD (https://www.diagnosisdiet.com/is-broccoli-good-for-you/)
Plant-based diets are supposed to be healthy, right? Unfortunately, there are many inflammatory substances in these foods. Learn the chemicals to watch for.
When I was 20, I read “The China Study”, which listed the miracles of a plant-based diet. In my experiments, I’ve found that the fewer plants I eat, the healthier I am.
I’ve listed 19 chemicals found mostly in ‘plant-based’ foods that can cause chronic inflammation and autoimmunity. Each person has a different immune system and can react differently to these substances. I’ve tried to list them in the order of importance for most people.
The foods mainly fall under the category of plant-based foods and secondarily cured meats.
Inflammatory Substances Naturally Found in Plant-Based Foods
Lectins are proteins that are found in every living organism, including viruses, bacteria, and pretty much all foods, to one degree or another – but most of them are harmless. Scientists have known about lectins since 1884.
The more nefarious of these proteins have the potential damage and destroy the cells in our intestines causing discomfort, poor digestion, and “leaky gut.”
Cell membranes in our body contain sugar molecules attached to fat and protein called glycolipids and glycoproteins (glyco=sugar). The lectins that harm our cells are chemically attracted to these sugar molecules and disrupt the cell wall.
Lectins can also spike inflammation in the gut, skin, joints and the hypothalamus in susceptible people.
Lectins are part of the defense mechanism of plants to protect them from being consumed .
Over time, our immune system has evolved to create antibodies that compete with lectins . Unfortunately, not all of us have the genetics that creates antibodies that protect us from every harmful lectin. This is why some of us are sensitive to the lectins in nightshades, and others are not.
On average, fifteen percent of a bean’s proteins are composed of lectins.
Studies show that bean lectins aren’t completely destroyed after soaking for 2 hours and cooking. In common beans, the lectin content declines from 820 to 3.2 (Hemagglutinating Activity), while in fava beans it declines from 51.3 to 6.4 .
Lectins can cause GI upset similar to classical food poisoning and immune responses like joint pain and rashes. Improperly prepared raw grains, dairy, and legumes like peanuts, and soybeans have especially high lectin levels.
A study was done on 800 people with autoimmune conditions who ate a diet that 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.
Most of these people had elevated TNF-alpha. The result after 6 months was a normalization of TNF-alpha in all patients who complied with the diet.
Dr. Gundry frowns upon foods that originated from America.
Biogenic or vasoactive amines are produced by bacteria during fermentation, storage or decay .
When plasma histamine levels are raised above the normal range (0.3-1.0 ng/mL) this produces certain effects. For example a level of 1-2 ng/mL causes increased gastric acid secretion and heart rate, with, flushing, headache, urticaria, pruritus, and tachycardia occurring at a level of 3-5 ng/mL), bronchospasm at a level of 7-12 ng/mL and cardiac arrest occurring at levels of 100 ng/mL .
Thus large amounts of ingested histamine can cause significant symptoms in otherwise well individuals. For example symptoms of flushing, sweating, urticaria, GI symptoms, palpitations and in severe cases bronchospasm may occur following the consumption of spoiled fish .
Due to the nature of the symptoms caused, reactions involving vasoactive amines may, therefore, be incorrectly diagnosed as a food allergy.
According to one study, mean levels of histamine were 3.63 mg/L for French wines, 2.19 mg/L for Italian wines and 5.02 mg/L for Spanish wines .
In a placebo-controlled study, one study found no correlation between wine histamine content and wine intolerance and concluded that other vaso-active amines or sulphites may be more relevant in intolerance to wine .
It has been proposed that other foods may be able to cause histamine release directly from tissue mast cells although evidence for this is lacking .
One study found that a diet low in vasoactive amines alleviated chronic headache in 73 % of patients .
Another study reported that 27/44 (61%) of subjects had a significant improvement in idiopathic urticaria, angioedema, and pruritus on a diet low in dietary amines, although foods containing additives or high in natural salicylate were also restricted .
Subjects with chronic hives or angioedema had a marginally significant reduction in their use of antihistamines on a histamine-reducing diet compared to a control group who eliminated artificial sweeteners from their diet .
58% of adult patients with irritable bowel syndrome (IBS) considered foods rich in vasoactive amines, such as wine, beer, salami, and cheese, to be a cause of their symptoms .
The diagnosis of sensitivity to vasoactive amines is usually made through history and dietary exclusion; however, some studies have suggested that the measurement of diamine oxidase (DAO) levels may be helpful. One study found a DAO level <3 kU/mL was associated with reported symptoms to high histamine foods, whereas a level of >10 kU/mL indicated histamine intolerance was unlikely .
Another study reported that the size of the skin prick test wheal to histamine after 50 min, the ‘histamine 50-skin-prick test’, was a useful diagnostic indicator; 82% of subjects with histamine intolerance maintained a wheal size greater than 3 mm compared with 18 % of controls .
Foods more likely to contain high levels of vaso-active amines and salicylate
|Vaso-active amines [16, 20, 21–22]||Salicylate [23, 24–25, 26]|
|Meat, poultry, and seafood||All cured meat especially pork products e.g. ham, salami, pepperoni, game, bacon, sausages, fresh pork, fresh or canned tuna, canned sardines, anchovies, mackerel, salmon, herring, processed fish products (fish pastes, smoked, dried or pickled fish), fish sauce|
|Milk and eggs||Blue cheese, parmesan, brie, camembert, Emmental, old gouda, cheddar cheese, and other hard cheeses|
|Fruits||Oranges, bananas, tangerines, pineapple, grapes, strawberries||Granny Smith apples, cherries, strawberries, currants, raisins, kiwi, Gala melon, peaches and nectarines, raspberries|
|Vegetables, nuts, seeds, and savory snacks||Tomatoes, pickled cabbage, aubergine, spinach, broad beans, peanuts, tree nuts||Asparagus, sweet corn, raw tomatoes, tomato puree|
|Condiments and miscellaneous||Fermented soy products including miso and tempeh||Ginger, mixed herbs, mustard, oregano, curry powder, black pepper, cardamom pods, cinnamon, cumin, fenugreek, mint, nutmeg, paprika, rosemary, thyme, turmeric, licorice, peppermint, Worcestershire sauce, honey, tomato ketchup|
|Drinks||Green tea, champagne, coffee, cocoa, chocolate, wine, beer, fresh fruit juices, smoothies||Coffee, pineapple juice, cider, Benedictine liqueur, lemon tea, black tea, apple juice, cranberry juice, orange juice, tomato juice, fizzy drinks, Drambuie liqueur, wine, rum|
I don’t believe all tannins are bad, but many of them stimulate the immune system too much.
Tannins are found in many plant foods and are considered anti-nutritional because they can cause problems with digestion and absorption of nutrients .
Tannins are a type of enzyme inhibitor that prevent adequate digestion and can cause protein deficiency and gastrointestinal problems.
Tannins give plants their color. Some are healthy and some are harmful (to people with an overactive immune system).
Human dietary sources of tannins are tea and coffee , wine (contributes to its bitterness) , cranberries , strawberries and blueberries . Apple juice, grape juices, and berry juices are all high in tannins. Nuts such as hazelnuts, walnuts, and pecans also contain high amounts of tannins.
4) Trypsin Inhibitors
It’s important to remember that plant foods have tens of thousands of chemicals and any of them can stimulate the immune system too much for your biology.
FODMAPs are short-chain carbohydrates (oligosaccharides), disaccharides, monosaccharides and related alcohols that are poorly absorbed in the small intestine. These include short chain (oligo-) saccharide polymers of fructose (fructans) and galactose (galactans), disaccharides (lactose), monosaccharides (fructose), and sugar alcohols (polyols) such as sorbitol, mannitol, xylitol, and maltitol.
The term FODMAP is an acronym, deriving from “Fermentable Oligo-, Di-, Monosaccharides, And Polyols.”
FODMAPs caused fatigue and gut problems in people who thought they’re sensitive to gluten (33).
Salicylate intolerance has been defined as a hypersensitivity reaction to salicylic acid, its derivatives or other related organic or inorganic acids of similar chemical structure .
Salicylic acid is widely distributed in plant foods (especially spices) and, like its synthetic counterpart (Aspirin), has anti-inflammatory activity. Namely, it inhibits COX-2 gene expression [38, 39].
It’s proposed that 2.5 % of Europeans may have salicylate sensitivity , but the evidence on which this assertion is based is sparse.
One study proposed that 2-7 % of all patients with inflammatory bowel syndrome and food allergies could be affected by salicylate intolerance . Gibson and Barrett suggest that since there are no published studies demonstrating
Oxalates (oxalic acid) are considered anti-nutrients.
Foods with oxalates include leafy greens, vegetables, fruits, cocoa, nuts and seeds .
Oxalates are found in the highest quantities in sesame seeds, soybeans, and black and brown varieties of millet.
Oxalates can bind to minerals to form calcium oxalate and iron oxalate. This mostly occurs in the colon, but can also take place in the kidneys and other parts of the urinary tract.
In sensitive individuals, high-oxalate diets have been linked to an increased risk of kidney stones and other health problems.
About 80% are made up of calcium oxalate .
However, most of the oxalate found in urine is produced by the body, rather than absorbed from food .
Some gut bacteria, such as Oxalobacter formigenes, use oxalate as an energy source, which significantly reduces the amount your body absorbs . Antibiotics decrease the number of these bacteria .
People with inflammatory bowel disease or gastric bypass surgery have an increased risk of developing kidney stones [47, 48, 49], partly because they are unable to regulate the amount of oxalate they absorb.
Foods High in Oxalate
Oxalates are found in almost all plants, but some plants contain very high amounts while others have very little.
Foods high in oxalate (100-900 mg per serving) include:
- Swiss chard
- Cocoa powder
- Sweet potatoes
Drink a lot of water can help with kidney stones.
Boiling vegetables can reduce their oxalate content by anywhere from 30% up to 90%, depending on the vegetable .
8-10) Sulphites, Benzoates, and MSG
I personally don’t have an issue with Sulphites, Benzoates or MSG.
Foods usually containing significant levels of added sulphite include cider, white wine, and dried fruit.
A plethora of reports in the 1980s demonstrated that sulphites in foods were provoking adverse reactions; by 1984 the US Food and Drug Administration had received more than 250 reports of suspected sulphite reactions including six deaths .
Foods containing a high level of free-form sulphites are more likely to provoke a reaction .
Sensitivity to sulphites mainly affects patients with asthma, especially those with severe steroid-dependant asthma. Sensitivity to sulphites has a reported prevalence of 3.9-4.6% in asthmatic patients, with those who were steroid dependent being most at risk .
A review suggested that 3–10 % of asthmatics experience symptoms on exposure to ingested sulphites .
An analysis of sulphite-sensitive cases in Korea found that two types of sulphite sensitivity existed, those with sulphite sensitive asthma was the most common, affecting two-thirds of their cohort, with the remainder having sulphite-sensitive hives (urticaria) .
One study found 16% of wine sensitive asthmatics responded to sulphite additives in wine .
Monosodium glutamate (MSG-E621) is a commonly added ingredient to savory foods. Glutamatealso occurs naturally in other foods, with the ripening of fruits such as tomatoes and the curing of meat such as ham being associated with an increase in the free amino acids such as glutamate.
Results from studies have been mixed, but overall seem to show that some individuals could experience symptoms from the ingestion of MSG, although only in quantities greater than the normal dietary intake .
A headache has been the most commonly reported symptom in relation to MSG .
In one blinded placebo-controlled trial, 61 subjects with self-reported sensitivity to MSG were tested. 18/61 had no response, 21/61 had a placebo response and 22/61 a positive response to the active challenge only. On re-challenge, a threshold dose of 2.5 g MSG was established .
In another small blinded placebo-controlled trial, 14 healthy individuals reported a significant increase in reported headache and pericranial muscle tenderness after taking a large dose of MSG (150 mg/kg – about 10g MSG for the average weight man) .
Foods more likely to contain high levels of natural or added sulphites, benzoates, and monosodium glutamate:
|Sulphites (E220–E227) [66, 67, 68, 69]||Benzoates (E210–E219) [58, 70, 60, 69, 71]||Monosodium glutamate (E621–E623, E627, E635) [72, 73]|
|Meat, poultry, and seafood||Prawns, lobster, dried salt cod, crab sticks, squid, meat burger, sausages||Dishes with a spicy sauce, ready to eat meals containing benzoates||Fish sauce|
|Milk and eggs||Yogurt, cheese||Parmesan cheese|
|Fruits||Dried apricots, sultanas, figs, prunes, dates, dried banana, candied or glace fruit desiccated coconut, currants||Cranberries, bilberries, prunes, papaya, dried fruit, avocado|
|Vegetables, nuts, seeds, and savory snacks||Dried mushrooms and other fungi, frozen, tinned or vacuum packed potatoes, French fries, instant mash, gnocchi, potato cakes, potato croquettes, vegetarian burgers and sausages, tinned asparagus, broad beans, French beans, chestnuts, walnuts||Pumpkin, kidney beans, soybeans, soy flour, broccoli, spinach, baked beans in tomato/spicy sauce, dry roasted and spicy nuts, Bombay mix, crisps (except ready salted), potato or corn snacks,||Mushrooms, spinach, savory snacks, crisps|
|Condiments and miscellaneous||Horseradish sauce, caramel coloring (E150)||Curry powder, allspice, mixed spice, nutmeg, clove, cinnamon, chocolate, cocoa, ketchup, soy sauce, Worcestershire sauce, salad dressing, salad cream, mayonnaise, jam, pickles||Soups, stock, gravy, rubs, coatings, ready-meals, soy sauce, black bean sauce, oyster sauce, tomato sauce, miso, marmite, instant rice, and noodle dishes|
|Drinks||Cider, wine, beer, fruit squash and cordials, soft drinks, grape juice, fruit juice drinks, cola drinks||Tea, squash, cordial, carbonated drinks, milkshake syrup, beer, ready-to-drink alcohol and mixers, spirits with added spices|
Foods likely to be high in added and/or natural ‘food chemicals’
|Herbs and spices||✓||✓|
|Strawberries and pineapple||✓||✓|
11-19) Other Anti-Nutrients in Plant Foods:
- Non-protein amino acids
- Alkaloids (includes solanine, chaconine)
High saponin foods include quinoa.
Phytic Acid (Also Called Phytate)
Phytate interferes with the absorption of minerals.
Phytic acid can block the absorption of phosphorus, calcium, copper, iron, magnesium, and zinc, and increase the absorption of copper.
Phytic acid also inhibits certain essential digestive enzymes (amylase, trypsin, and pepsin).
Gluten is one of the most difficult-to-digest plant proteins. It’s an enzyme inhibitor that has become notorious for causing gastrointestinal distress.
Isoflavones are highest in soybeans. It can have estrogenic effects and cause hormonal changes and contribute to digestive issues. These are considered endocrine disruptors.