Is Broccoli Good for You? Meet the Crucifer Family…

cruciferous vegetablesPublic 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

  • Arugula
  • Bok choy
  • Broccoli
  • Broccolini
  • Brussels sprouts
  • Cabbage
  • Canola
  • Cauliflower
  • Chinese Broccoli
  • Chinese cabbage
  • Choy sum
  • Collard greens
  • Horseradish
  • Kale
  • Kohlrabi
  • Mizuna
  • Mustard Greens
  • Mustard Seeds
  • Radishes
  • Rapini
  • Rutabagas
  • Turnips
  • Wasabi
  • Watercress

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.

Sulforaphane 101

  1. Sprouts contain 20 to 100 times more glucosinolate than mature vegetables (to protect the baby plant).
  2. Freezing crucifers or boiling them for 10 minutes reduces glucosinolate concentrations by about 50%.
  3. Steaming reduces glucosinolate concentrations by about 2/3.
  4. 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.
  5. 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.
  6. 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…

For information about how cruciferous vegetables can aggravate IBS in some people, read my blog post: “Common Constipation Culprits.”

To read more about vegetables in general, visit my Vegetables page or watch my 20-minute presentation entitled Little Shop of Horrors: the Risks and Benefits of Eating Vegetables, given at the 2012 Ancestral Health Symposium.

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Tagged with:


Assayed M and Abd El-Aty AM.  Cruciferous plants:  phytochemical toxicity versus cancer chemoprotection.  Mini-rev Medic Chem 2009: 1470-1478.

Cavell BE et al.  Anti-angiogenic effects of dietary isothiocyanates: Mechanisms of action and implications for human health. Biochemical Pharmacology 81 (2011) 327–336.

Hayes DP.  Nutritional hormesis. European Journal of Clinical Nutrition 2007; 61, 147–159.

Herr A et al.  Dietary constituents of broccoli and other cruciferous vegetables: implications for prevention and therapy of cancer. Cancer Treatment Reviews 2010; 36: 377–383.

Latte KP et al.  Health benefits and possible risks of broccoli–an overview.  Food and Chemical Toxicology 2011;49: 3287-3309.

Nakamura Y and Miyoshi N. Electrophiles in foods:  the current status of isothiocyanates and their chemical biology. Biosci Biotechnol Biochem 2010; 74(2): 242-255.

Rungapamestry V et al.  Effect of cooking brassica vegetables on the subsequent hydrolysis and metabolic fate of glucosinolates. Proceedings of the Nutrition Society 2007; 66: 69–81.

Yanaka A et al.  Dietary sulforaphane-rich broccoli sprouts reduce colonization and attenuate gastritis in Helicobacter pylori-infected mice and humans. Cancer Prev Res 2009; 2:353-360.

Zhang Y and Callaway EC. High cellular accumulation of sulphoraphane, a dietary anticarcinogen, isfollowed by rapid transporter-mediated export as a glutathione conjugate. Biochem J 2002; 364(Pt 1): 301-7.

Tagged with:
  • How can I replenish my glutathione if I eat the vegetables?

  • How do I replenish my glutathione after eating broccoli and the like?

  • Hi Carol,

    Interesting question! Glutathione is made from three amino acids: glutamate, glycine and cysteine. Cysteine is the scarcest of these three, and is special because it contains sulfur, which is required for the antioxidant activity of glutathione. Animal foods are rich in cysteine, whereas vegetarian protein sources tend to contain less cysteine. If you are eating enough animal protein every day, you should be fine. Some people choose to take cysteine in a supplement form called “N-acetylcysteine.”

    • Pauline

      Hi Dr Ede,

      I’m sure you must have come across the idea of hormesis, where a small amount of something slightly toxic induces a beneficial change in the body, while larger doses are detrimental. That’s kind of how exercise helps build muscle, so long as you don’t overdo things.

      Interestingly, broccoli is high in cysteine. Perhaps eating broccoli stimulates and enables production of glutathione, which is protective against lots of things, not just eating broccoli.

      Food for thought anyway.

  • Dear Des from Toronto,

    If you would kindly post your excellent questions about crucifers here in the comment thread I can answer them more easily:)

  • Des

    Hello Georgia, great post! I was wondering, if our bodies are so good at excreting sulforaphane within 3 hours, why should broccoli be a worry to us?

  • Hi Des

    Good question. Unfortunately we do not know whether we should be worried or not, or if so, how worried we should be, because it would be very hard to design a study that could answer that question. My take on cruciferous veggies (and all vegetables, for that matter) is this: I’m not convinced we need them, I’m not convinced they provide health benefits, and they may be irritating to some people, especially people with food sensitivities, compromised immune systems, or leaky gut. Also, if people are eating them very frequently, they could have significant amounts of sulforaphane in their cells most of the time. However, big picture thought: most cultures have been eating vegetables for millions of years, so we likely have adapted to plant irritants fairly well after all this time. This probably explains why we have such an efficient mechanism for removing sulforaphane from our cells in the first place. Who knows?

    • Des

      Thank you Georgia, that makes sense. It’s just hard to picture not eating any veggies or fruits. My diet consists of coconut, fish, meat, eggs, fruits and vegetables. My partner is afraid that if we cut down on veggies, we’ll become constipated! But I believe you’re on to something.

      Also, you mentioned that plants don’t want their bodies to be eaten- does that mean fruit is a better option because it wants to be eaten?

      Thank you kindly for answering these questions!

      • Hi Des

        Many people do just fine with vegetables, so you may not need to make any changes unless you are having symptoms you cannot otherwise explain. Furthermore, there are quite a few vegetables which are actually fruits in disguise: cucumbers, squashes, avocado, tomato, eggplant–any vegetable with seeds, essentially. However, if you have issues with chronic pain, arthritis or heartburn, the nightshades may be problematic (more to come in a future blog post and/or see video on my veg page). Many vegetables, especially the cruciferous vegetables and raw vegetables can actually contribute to constipation (see constipation blog post), as can any nut (including coconut). Whether or not you eat can eat fruit depends on your level of insulin resistance/glucose tolerance (see fruits page).

        • Des

          Thank you so much:)

  • ACB

    So should I stop stressing about the lack of vegetables in my son’s diet? Interesting ideas. Thanks.

  • Hi Ann

    Hmmm…what an intriguing question. This is a toughie, because if I give my blessing to a vegetable-free diet for your son, lawsuits may begin to fly! It would not be the standard of care to recommend such a diet, and I am not permitted to give medical advice on the internet. So, let me try to answer the question as a hypothetical.

    Vegetables are high in some vitamins and minerals, although the majority of them are in a less useful form than in animal foods. A completely vegetable-free diet can be nutritionally complete, depending on what is being eaten instead of vegetables. For example, if a person is eating sufficient animal foods, including occasional organ meats (such as liver), all necessary nutrients will be present in his/her diet.

    If organ meats such as liver are excluded, It is theoretically possible to develop a folate deficiency, because muscle meats are lacking in a few nutrients that are very high in veggies, folate in particular. Liver is a very rich source of vitamins.

    However, if a person eats too many refined carbohydrates, chemical additives and natural plant anti-nutrients (i.e. from legumes and grains) that can interfere with the utilization of the nutrients in foods, then the nutritional value of an otherwise complete diet could be compromised.

  • Des

    Good morning Dr.Ede, thank you for taking the time to answer all these questions! My next question has to do with the acidity in animal foods. I came to understand that animal foods are highly acidic and veggies buffer the acidity and keep the body in a more alkaline state which is said to be healthy. We certainly don’t want to be in a state of acidosis. Or is the acid/alkaline theory overblown?

    • Hi Des

      Good question This is another one of those issues that I need to get to the bottom of. I am very suspicious of the theory, because it doesn’t make sense to me. The body is expert at regulating the pH of the blood, keeping it in a very narrow range at all times, regardless of what we eat. If this theory were true, then the world could not contain species that ate only plants or species that ate only animals, because there would be significant acid-base balance problems for nature to address. Every time I’ve started to dig into this topic, a funny thing happens: the more I read about it, the more confused I get. In my experience, that is a sign that the theory is a twist of logic–a hypothesis designed to try to explain the belief that meat is bad for us…but I’ll keep working on it. If I figure it out, I’ll add the information to the meats page.

      • Des

        Yup, I thought so. Also, if it were true, Eskimos would be seriously messed up, but they’re not.

  • Des

    Also, the real issue is ketoacidosis which is lethal to diabetics. It sounds misleading because it could make someone think that if they go into a state of ketosis, which is normal and healthy, they can develope this horrible symptom. But they can’t, can they?

  • While it is very common to confuse ketosis and ketoacidosis, ketoacidosis is not usually the reason why nutritionists worry about meat and blood acidity. Ketosis and ketoacidosis are completely different biological states. Ketoacidosis can only occur in people who are unable to produce any insulin at all (i.e. type I diabetics), which allows ketoacids levels to rise to dangerous levels, causing the pH of the blood to drop to dangerously acidic levels. This is impossible in everyone else.

    • Des


  • I received an anonymous question from a reader that I have permission to post here:

    Hi Dr. Ede,

    I am someone who suffered from bipolar tendencies, acne, and IBS while a
    vegetarian. I found a couple of doctors who got me tested for IgA antibodies (from Enterolab) and IgG antibodies (from Alletess); lo and behold, I had a ton of food sensitivities (gluten, casein, soy, egg, nuts, seeds, legumes, tomato, garlic, etc.). The common factors, from what I’ve read, seem to be glutamate and lectins. Since eliminating all of these things from my diet, I’ve pretty much eliminated the acne, IBS, and
    bipolarity; plus, I lost 40 pounds.

    After this elimination, I found that eating most vegetables caused me digestive
    distress, and so eliminated vegetables, for the most part, as well (and thanks to your work, I no longer have to feel bad about this). Still, no matter how much meat I eat, I find that I still crave fruit and starch. Most fruits don’t seem to cause me problems, as long as I listen to my body. Still, no matter how much fruit I eat, in addition to unlimited meat, I still find myself craving starch. I try to eat uncombined, minimally processed, whole foods, whenever possible, so I just recently added potatoes and sweet potatoes back into my diet. In part, this was inspired by a book that was recently published by Richard Wrangham called _Catching Fire: How Cooking Made Us Human_, in which he
    argues that cooking roots and tubers was essential to human cortical evolution.

    If I have read you correctly, you seem to be saying that starches and fruits are completely unnecessary, and in many cases unhealthy. And if I read between the lines, it seems as though you imply that people who have access to healthy meat would be best off forgoing plants altogether, or almost altogether. Am I reading you correctly? I understand that there may not be a one-size-fits-all approach to human diet, but I am curious what plant matter and how much plant matter you think a generally healthy American should ideally be eating to maximize their healthiness.

    In order to not get lost in abstractions, I’d be particularly interested in
    reading what *you* actually eat, in precise detail, on any given day. I’d also
    be interested in reading what you think would be an ideal diet for yourself, on
    any given day, if you were to have unlimited time, access to ingredients,
    self-control, and a personal chef.
    –Someone, Somewhere

  • Dear Someone,

    I love hearing these amazing personal success stories of people who have regained their health by changing their diet in unique ways!

    As for starch cravings, the only way I know of to guarantee their disappearance is to eat a very low carbohydrate diet (this would mean removing nearly all fruit, for example). Prof Wrangham’s book is on my (LONG) list of books to read, as I, too, have heard that hypothesis. As soon as I have read it, I will post a review on my site.

    I do not pretend to know what the ideal human diet is, and would not wish my own diet on anyone, given that I have many food sensitivites that restrict my menu rather substantially. However, the more I learn, the more convinced I become that humans do not need plants in their diets. I can’t find any evidence that we do, anyway. I personally feel better when I avoid them, and I have been told by some others that I am not alone in that regard.

    And btw,yes, I would absolutely LOVE to have unlimited time, boundless access to ingredients, self-control and a personal chef. Please send immediately:)

    • Someone, Somewhere

      Dear Dr. Ede,

      Thank you for your prompt and informative reply to my comment (below). I appreciate what you’re saying here about starch cravings. I guess I’m skeptical that it’s healthiest to remove starch and sugar from one’s diet altogether. Starchy roots and tubers, as well as seasonal fruits, I imagine, were available in varying degrees in our ancestral environment. And they can be enjoyed with minimal adulteration (zero processing for fruit, and simply being dropped in a campfire for a potato). I realize that there are populations that have subsisted without plant matter, but these seem to be extremely rare exceptions to the rule, and only the case because plant matter wasn’t available. Proof of concept, yes, but not proof of what’s most adaptive, natural, or healthy, I think. I agree with your aversion to vegetables (minus starches)—I certainly *don’t* have cravings for veggies, unless they’re highly adulterated—but we seem to be hard-wired to enjoy fruits and starchy roots and tubers, and I’m very hesitant to go against the apparent wisdom of millions of years of evolution. I have gone for long periods without fruit, and even longer without starch (a year or longer), but when I’m really honest with myself about how I feel, I sense that these cravings have never waned, which suggests to me that it’s not simply a matter of addiction or accommodation.

      I appreciate your openness about your aversion to plants. I guess the reason I asked about your personal diet is that I’m interested in what a sustainable plant-free diet would actually look like, in terms of what meats are used and how they’re prepared, on a concrete, day-to-day basis. There’s a wide diversity of animal products available, and a wide variety of preparation methods available as well. I’d be curious to try an all-animal diet, but other than throwing a completely unadulterated steak on the grill, I wouldn’t know where to start. Would you be willing to share a typical daily menu of your own, or one that would work for someone on a plant-free diet, including what fats and seasonings (if any) and what cooking methods one would use? I’m having trouble wrapping my head around this, and would like to be able to, so I can see ways in which I might avoid plants more and still enjoy eating 🙂

      Thanks again for your support!

      • Someone, Somewhere

        UPDATE: It seems that I spoke too soon. I had been craving starch, but when I actually let myself eat starches that were uncombined with other ingredients—potatoes, sweet potatoes, plantains, and winter squashes—over the last couple of days, I found that they weren’t really satisfying after all. What I had missed, apparently, was not the starch, but the cooking substrate that had made the starch palatable: fat. Without added fat, I find that starch is a poor substitute for what my body seems to really want: fatty meat, and fruit. And so, Dr. Ede, your admonitions against eating starch are now well-taken 🙂

        That said, the desire for fruit remains strong, in spite of the fact that I eat it completely unadulterated. But I’m trying to keep an open mind here. So I’m still curious what a satisfying plant-free diet could look like, on a day-to-day basis, if you’d be willing to share. So far, grilled grass-fed steak, broiled mussels, and steamed whole wild shrimp are the only grass-fed/wild meats I’ve found that I enjoy eating with zero seasoning, but I’m open to other ideas, should you have any to share 🙂

        • Hello, Someone

          I am a lousy cook and menu planner, so be careful what you wish for…all I can say is 1) the best way to get fruit cravings to go away, if you want them to go away, is to limit carbs to max 50 g/day (some people need to go lower) for at least 3 consecutive days, and 2) an all-animal diet, so long as it includes plenty of fat and occasional organ meats (liver, especially), should be safe and nutritionally complete. I think it’s more important to eat a diet you can actually sustain than to eat 100% grass-fed/wild-raised meats, so you may want to add some conventional fresh meats to your menu if you feel limited. You may find you want to use vegetables and fruits as seasonings/condiments (lemon juice, olive oil, spices, etc) to keep your diet interesting, rather than eating them in significant amounts as main dishes or side dishes.

          • Amber

            Hello Somebody,

            I eat essentially only meat (I also resolved bipolar tendencies and shed a lot of excess fat), and I’ve described what I eat a little on my blog: http:// (also see the comments).

            On a typical day, I might have leftovers from supper for breakfast, steak for lunch, and chicken or pork for supper. I eat mostly only fatty cuts, and if the meat is too lean I’ll add butter or tallow to it. My family goes through a lot of bacon, and so I also have a lot of bacon grease for frying.

            I usually can’t afford grass-fed, but that hasn’t prevented my diet from putting my big issues into remission.

            Another thing I do for added fat is to put coconut oil in my coffee. Since you don’t eat nuts, that might not agree with you, but on the other hand it might — I can’t eat whole coconut, but the oil seems to be fine. It does have salicylates, though. If you do try it, it’s best blended. That way it emulsifies and gets foamy, rather than sitting on the top.

            There is also a facebook group called Zeroing In On Health for those eating only meat. They would probably have many great suggestions.

          • Someone, Somewhere

            Thanks, Dr. Ede. Very helpful. I’ll give it some thought.

        • Jane

          I have found that I cut carb cravings when I use organic virgin coconut oil in my cooking. If I am craving more food after I have eaten a meal, it usually means I haven’t had enough good fats like coconut oil. I used to have to buy it online, but even Costco has it nowadays.

          • Someone, Somewhere

            Thanks, Jane, for the suggestions.

            I’ve tried organic virgin coconut oil a few times, but for some unknown reason, I find the taste somewhat disgusting. Besides, I prefer the simplicity and naturalness of cooking meats in their own attached fat, as our ancestors probably did.

            By the way, it’s not carbs, per se, that I generally crave. It’s the acidity of fresh fruit that I crave, particularly after eating meat. And I enjoy this acidity only when it’s balanced by the sugar that naturally occurs in most fruits. I crave and drink fruit juice only right after eating meat, so I imagine my insulin levels are protected by the protein and fat in the meat, which slows the sugar absorption. At other times, I eat fruit whole. If I drink fruit juice on an empty stomach—which I almost never do—I feel anxious, which suggests that it causes spikes in my blood sugar levels, but when I drink juice after eating meat, or eat whole fruit at any time of day, I feel calm and happy, which suggests to me that my blood sugar and insulin are doing just fine.

            I must admit: While I am persuaded by Dr. Ede that vegetables and seasonings probably do more harm than good for modern humans (due to the toxins and non-nutritive substances therein), I am not persuaded that this is the case with fruit. Humans have presumably adapted to eat fresh fruit through millions of years of natural selection. We can survive without fruit, but that doesn’t mean that doing so is ideal for health or happiness. The fact that I crave fresh fruit juice, in particular, only after eating meat, suggests to me that the antioxidants therein are, despite Dr. Ede’s claims to the contrary, helpful in combatting oxidation. This is not to mention that plethora of apparently health-promoting substances in fruits, many of which, I imagine, have not yet been identified. Suffice it to say that fruits and humans have evolved symbiotically. I have yet to see compelling evidence that sugar is deleterious to human health, when eaten in it’s natural form (i.e., as part of whole fruit). But I am open to evidence to the contrary.

  • Someone, Somewhere

    Thanks, Amber. I’ve subscribed to your blog and checked out Zeroing in on Health. I’m intrigued by the idea of a meat-only diet. I’m going to give it some more thought. Thanks again for your suggestions.

  • Des

    Since stumbling upon this blog, I’ve modified my diet which has been Paleo for 3 years (before that, I was a vegetarian living off cheap rice noodles, broccoli and chickpeas. Bad idea). So I basically eat the same sorts of foods daily. I don’t really feel I need to eliminate ALL fruits and vegetables simply because they add bulk, color, flavor and richness to meals. Here’s a sample of what one can do on a low fruit/veg diet.

    Pre-breakfast: large glass of water. 1 tsp cod liver oil.

    Breakfast: 2 mugs of black French Press coffee. One tablespoon coconut oil, or 1/2 cup coconut milk. 1 banana.

    Lunch: 2 whole eggs fried in ghee or duck fat with smoked salmon or bacon on the side. A bowl of elk bone broth with bone marrow.

    Dinner: fried ground bison, or steak, or fish in ghee or red palm oil, fresh parsley, basil, crushed tomato sauce. Some duck pâté on the side.

    Snack: 1/2 cup wild blueberries or 1/2 pomegranate. Herbl tea.

  • Someone, Somewhere

    This isn’t exactly related to crucifers, but this is the best place on your site to post it: I’ve been thinking lately about whether to use spices/seasonings when preparing meat. I prefer to prepare meat without seasonings for a number of reasons:

    1. Medical testing has revealed that I have intolerances (elevated IgG antibodies) to a number of seasonings (e.g., garlic, basil, black pepper, mustard, MSG).

    2. Spicy foods give me stomachaches.

    3. Cooking without seasonings is much quicker, easier, and simpler.

    4. Cooking without seasonings forces me to be much, much pickier about the meat I choose, which I suspect makes me healthier. With seasonings, I can take the cheapest cut of pork, beef, chicken, etc. and make it taste good. Without seasonings, I can taste the meat much more acutely, so I’m forced to choose the freshest shellfish, the fattiest grass-fed ribeye steak, etc. It drastically reduces the options that are palatable to me, but I suspect that that’s a good thing, because I suspect that this forces me to choose meats that my body is much more highly adapted to eating.

    5. You, Dr. Ede, have made compelling arguments for why plants tend to be hazardous to human health.

    Still, I found myself wondering: Why does seasoned meat often taste so good? And how can I reconcile this with the reasons I just articulated for *not* seasoning the meat I cook?

    I just found an article today that seems to provide some answers to these questions, well-summarized at

    The research shows throughout the world, the use of spices and seasonings on meats correlates positively with how hot the climate is in a particular region. And so, the closer the region is to the equator, the more spices and seasonings are used. The researcher explains that, historically, meat with more likely to spoil in hotter climates, so spices and seasonings were used to reduce spoilage (he also cites research showing that spices and seasonings do, in fact, kill pathogens quite effectively).

    That said, spoilage seems to be way less of a problem than it was previously, even in warm climates, due to modern refrigeration and food handling practices (at least in developed countries like the US). So it seems that the pros of seasoning meat may no longer outweigh the cons?

    There is also the issue of oxidation, with some nutritional experts claiming that spices and seasonings act as antioxidants to prevent oxidation of meats or to counteract the oxidation when eaten. I don’t know whether these claims are backed up by research or not. On the other hand, cooking methods also influence oxidation: The cooking method of steak preferred by the most people (according to the research I’ve seen) is medium-rare throughout the inside, well-seared on the outside. Cooking the inside to no more than medium-rare apparently minimizes oxidation therein, while searing the outside to a golden brown creates antioxidants. So carefully cooking meats may not suffer from oxidation problems, even without spices and seasonings, it seems. And personally, I find that drinking a glass of antioxidant-filled orange juice alongside my meat is all I need to feel balanced 🙂

    That said, I did read an interesting case study about unmarinated, unprocessed, cooked pork causing coagulation of red blood cells, while marinated or preserved pork did not, but it’s hard to know what to make of this study, because it leaves many questions unanswered:


  • C. D.

    Great Blog! Thanks for writing it. It follows along with Dr. Ray Peat’s research:

  • Hi C.D.
    Thanks for the great link–his site looks like a great resource!

  • Hello, SS

    Re: spices–yes, absolutely. I was aware of the historical purpose of seasonings, all of which makes intuitive sense to me given what we know about the natural toxins in plant substances. Spices can be very troublesome to those sensitive to plants bc their intense flavor generally indicates high concentrations of plant defense compounds.

    Meats are the foods least likely to cause oxidation. if you care about oxidation status, that orange juice is mostly pro-oxidizing due to its high sugar content…

    I read the Weston Price pork article–very interesting. Only 3 subjects, so who knows what their observations might mean, but intriguing. I don’t do well with pork myself and have never understood why. I still don’t, but I’ll keep an eye out for more information. Thanks for sharing it!

    • Someone, Somewhere

      Thanks, Dr. Ede. Can you refer me to any research related to your claim that meats are the foods least likely to cause oxidation, and that unprocessed fruit juice is pro-oxidizing? I’m intrigued.

      • That is a tall order because my take on this topic is the result of broad reading in many fields. There is no one article that I can point to that will help here. However, I will be writing more about this topic in the future.

        • Someone, Somewhere

          Thanks, Dr. Ede. I’ll look out for your upcoming post on this topic.

  • Des

    Dear Dr. Ede, my brother wants to cure his enlarged hemorrhoid and avoid future surgery. He feels great on a diet of meat, potatoes and bananas but is worried that such a diet may hurt his heart, arteries, etc. I believe he’s on the right path, do you concur?

    • I’m sorry, I cannot provide medical advice on this site.

      • Des

        Okay, thanks

        Des Diamantopoulos,
        Certified Renaissance Exercise Instructor

        21 Camden St. #100
        Toronto ON M5V 1V5


        Sent from my iPad

      • Zuleika s

        Dr Ede I hope it’s not to late but if veggies and fruit are not safe what is good.. I would like more information on what to eat..

  • rob

    What about coconut oil and palm oil? I don’t eat the stuff, but I have a couple gallons of each left over from when I used to. I have been using them as lotion, but now I’m wondering if that’s not such a good plan. I have enough to turn into soap: what do you think, would it still be toxic as soap? Thanks in advance.

    • rob

      The palm oil is of particular concern to me as it is unrefined with a very strong odor and dark color. It must be full of plant chemicals. Should I continue to use it as lotion or soap? Thank you so much.

      • Hi Rob

        I wish I had a good answer for your interesting question but I haven’t researched the effects of plant oils when used as skin products, since my focus is on how foods affect us when we eat them. However, palm oil is from the fruit of the palm (as opposed to palm kernel oil, which comes from the seed), and by and large, fruit compounds tend to be more benign than seed or vegetable compounds. It is also unclear to me whether nuts are as irritating as other seed foods (see my grains/beans/nuts/seeds page for more info about that). I’m sorry I can’t give you better guidance…

  • G6PD-deficiency sufferer

    Dear Someone,

    thank you for this article. I know finally know why I can’t eat crucifarae! Thank you so much for this (funny and) easy-to-understand-explanation!

  • Pamela Piccirillo

    Dear Dr. Ede, Does microwave cooking denature glucosinolate?

  • Michael

    Ah, the not-very-well-known fact about the plant kingdom: Anti-nutrients. It’s not just the crucifer family, somehow EVERY plant on earth has some kind of defense mechanism.

    • Walter Stuart

      Obviously! The world is just full of organisms looking for food, not to mention organisms with adaptations to allow them to nullify the plant defenses. The big struggle for many which all plants have to fight is in the soil, which is full of bacterial, worms etcetera which recycle dead matter.

      OK, some parasitical plants don’t reach into the soil and thus are free of that battle.

      When a plant dies it is immediately starts to rot, with a few exceptions, of plants that saturate themselves with toxins.

  • Pat smith

    I suspect it is too late to join this discussion but I just found you. I am struggling to make sense of a cauliflower protecting its final product, the head. For what purpose would a plant put such a magnificent head on top. Not to eat, apparently, so what purpose is all this enormous variety of vegetables bringing to the world’s “table?”

    • Hi Pat

      Interesting question! As I understand it, cauliflower heads are made of lots of tiny, compact flower buds that haven’t yet bloomed. This is the stage at which humans like to eat them. The way cauliflower reproduces is to create flowers that attract pollinators like insects and birds. After pollination, seed pods form that later burst open to release seeds into the environment. So cauliflower would not “wish” to have its buds eaten before flowering, as flowering in order to reproduce is the whole purpose of the magnifcent head:)

  • Alice

    No Champagne? No brocolli? No jacket potatoes? No fermented or aged foods? Eating lots of red meat gives me bad breath. Humans have eaten plants for thousands of years. Some, and varied plant food is part of our omnivorous diet. I don’t want to eat just meat and fruit. There is probably no perfect, ideal diet for us as we adapt to, and challenge our bodies with the food we eat.

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