Vegetables Are Trying to Kill You
By ryan heeney / February 7th, 2024
If you think about it—there are only 2 foods on earth that actually “want” to to be eaten (or are designed to be eaten).
Milk and fruit.
Milk is almost a perfect food on its own, created to be consumed, while containing practically everything needed for survival. While the subject of whether or not a human adult should be consuming milk can be debated, we know that humans have been consuming animal milk for at least 6,000 years. You can read about that here:
https://www.sciencedaily.com/releases/2019/09/190910105353.htm
As for fruits—the fruit of a plant is designed to be eaten because the plant “desires” for its seeds to be dispersed by the animal eating the fruit for reproduction sake. One of the most common ways an animal does its part in this symbiotic relationship is by consuming the fruit and later excreting the seeds in a different location (along with a bit of fertilizer (the animal’s poop) as a bonus).
A sweet, juicy fruit is so appealing on its own because the fruit is designed by nature to be appealing to a passerby and then eaten as a means of reproduction. In fact, it’s thought by some that a major reason us humans have color vision is specifically for seeing ripe fruit against a background of green foliage.
https://www.sciencemag.org/news/2017/02/you-can-thank-your-fruit-hunting-ancestors-your-color-vision
As a side note: Isn’t it interesting that fresh milk and fresh fruit taste so good on their own without any processing, cooking, added sodium, seasonings, etc.?
On the other hand, if you ever were to google what a cashew looks like in its natural form I think you’d be surprised at just how inedible it really is (even after you get it out of its poisonous shell). Cashews are surrounded by a shell that consists of the toxic oil urushiol. Coming into contact with urushiol can cause itching, blisters, and skin rashes. Finally getting to the cashew is a very labor intense process.
Cashews in their natural state are covered in a poisonous shell, almost as if nature is giving us clues as to what we were meant to eat if we pay close attention.
Everything on earth that’s living wants to survive and reproduce, just like we do. Animals have teeth and claws to defend themselves—plants on the other hand only have chemicals for their defense.
An interesting anecdote I once heard was from a guy named Chris Young. Chris has a background in biochemistry, mathematics and working as a chef. In the video below, he gives his view on raw vegetables and some of the downsides related to including them in your diet.
Another broad, general term for these defense chemicals when thinking about human nutrition could be “antinutrients”. Some of these toxins or antinutrients include certain phenols, tannins, lectins/agglutinins, trypsin-inhibitors, along with an innumerable amount of other metabolic inhibitors. Unsaturated fats themselves are important defenses, since they inhibit trypsin and other proteolytic enzymes, preventing the assimilation of the proteins that are present in seeds and leaves. This disrupts all biological processes that depend on protein breakdown, such as the formation of thyroid hormone and the removal of blood clots.
While most of these defense chemicals don’t cause an obvious acute reaction (although some do like poison ivy), these chemicals slowly affect their attacker over months, years and generations.
I think nutrition researcher Georgi Dinkov summarized this subject terrifically in a post which you can read here:
“The goal of most plants is to have as many of their seeds spread as far as possible. Thus, plants often encapsulate seeds in appetizing wrapper to entice organisms to ingest the seeds. At the same time the seeds contain substances that would inhibit the ability of this organism to digest (destroy) those seeds. One of the most commonly used substances by the plants are the oils found in the seeds. Seed oils happen to be a powerful suppressor of both digestive and metabolic activity (the two are closely related). Most vegetable oils sold on the market are extracted from seeds (sunflower, cottonseed, canola, rapeseed, soybean, peanut, etc), and as such are likely to suppress both metabolism and digestion. In addition, many of the seeds contain toxic substances based on the well-known poison cyanide to further discourage organisms from attacking/eating the seeds. (Pro)anthocyanidins and some of the most common cyanide-derived poisons are found in virtually all seeds.
https://en.wikipedia.org/wiki/Proanthocyanidin#Biological_significance
As a general rule, the seeds of a plant contain the most powerful toxins and should be avoided as food unless there is nothing else available. In contrast, olive oil and coconut oil are extracted from the actual fruit and not from seeds. I guess another distinction is that both olive and coconut oil are actually fruit oils and not vegetable oils. The fruit is typically meant to be eaten as a means of spreading the seeds and usually contains beneficial substances like sugars and pro-metabolic oils.
The vegetable plant, as opposed to the seeds, is usually less toxic when eaten but it is still very difficult to digest (most plants are mostly cellulose and water) and it is usually not very calorie-dense. Given our large brains and daily caloric demands, it just does not seem likely that vegetables (and derivative oils) are the food we are supposed to eat the most.”
Cellulose is an insoluble substance and is the main structural component of plant cell walls and vegetable fibers. It is a polysaccharide (a type of carbohydrate) consisting of chains of glucose. Here you can see more a visualization of what cellulose actually looks like:
Humans cannot digest cellulose because they lack the enzymes essential for breaking the beta-acetyl linkages.
If you did choose to include plants in your diet, one of the reasons you would want to cook the plants well is because of this cellulose. It might be helpful to think of cooking plants as almost a predigestion. Not only will you digest them better after cooking, but you will be utilizing more of the nutrients within the plant after the cellulose has been broken down and the nutrients have been “freed” from the plant’s cell walls. Remember, the fruit of the plant should typically be eaten in its raw state but the stem, leaves and root of a plant are better off cooked. Not to be crass, but if you’ve ever eaten a large salad full of raw vegetables and leafy greens like kale, later on or the next day you will be able to tell that most of it wasn’t fully digested. Not to mention all the gas and uncomfortable bloating you might experience after as well.
The first time I had ever heard of kale being talked about as a food (and not as the that green leafy decoration that is typically used to put around buffets) was around 2008. I had read a book by Dr. Joel Fuhrman called “Eat for Health” and in it he had devised a system that would rank foods based on their nutritional content in contrast to how many calories a food had. In other words, the foods with the most nutrients and the least amount of calories would get the highest score. The nutrients he included in this formula were: fiber, calcium, iron, magnesium, phosphorus, potassium, zinc, copper, manganese, selenium, vitamin A, beta carotene, alpha carotene, lycopene, lutein and zeaxanthin, vitamin E, vitamin C, thiamin, riboflavin, niacin, pantothenic acid, vitamin B6, folate, vitamin B12, choline, vitamin K, phytosterols, glucosinolates, angiogenesis inhibitors, organosulfides, aromatase inhibitors, resistant starch, resveratrol plus their ORAC score. He called this the Aggregate Nutrient density Index (or ANDI for short). Foods would be ranked on a scale of 1-1,000, with 1,000 being best. Well it turned out kale was at the very top of that list with a score of 1,000. After seeing that, I headed to the grocery store to load up on my kale and attempted to include it in every meal I could.
I decided to give the rest of Dr. Fuhrman’s guidelines a try too, but I soon started experiencing bloating, digestive issues, a reduction in energy levels, bad insomnia, irritability, changes in the quality of my teeth, hair and nails, etc. In fairness to his guidelines, I could have been under eating, but I think that’s a large part of the problem with focusing so much on micronutrients and phytochemicals.
Looking back now here are a couple possibilities of why it wasn’t a success:
The diet is full of raw vegetables and wreak havoc on digestion (granted some in the book are recommended to be cooked).
He is too focused on micronutrients and phytochemicals but I believe nutrition is much more than that.
He seems to underestimate macronutrients (protein, fat and carbohydrate). For example, fructose (a type of simple sugar) stimulates the liver to turn the thyroid hormone T4 into T3 which increases the metabolism, in turn massively increasing the production of carbon dioxide. This increase in carbon dioxide allows the body to use vitamin K to a much greater degree.
He missed some extremely potent nutrients. Something like naringin has strong anti-inflammatory and antioxidant activities and that was not included in his list.
Some micronutrients he touted as healthy are actually quite anti-metabolic which I would not recommend consuming (like beta carotene, a precursor of retinol). In my opinion, getting retinol directly is much more metabolically friendly. Perhaps these types of misconceptions can be an article of their own in the future.
The calorie itself in a nutrient. Yes, obesity is an issue in the Western world, but many people suffer from illnesses that can worsen when someone is underweight. There’s even something called “the obesity paradox” where those who are slightly overweight tend to live longer than those who are underweight. You can read about that here: https://pubmed.ncbi.nlm.nih.gov/29981771/
I think this chart below which I had posted in one my earlier articles would be very helpful when considering micronutrients and how they play just a part of the picture—and not nearly the whole picture when health is considered:
In my opinion, nutrition is all about context, and to focus and give advice with such a narrow focus on micronutrients is shortsighted and even irresponsible to be honest.
Looking back, I can’t believe those established in the nutrition world at the time accepted this nonsense as clever. But more surprisingly they actually still do. Dr. Fuhrman gave a Ted Talk in 2014 and is still making the circuits today.
Now don’t get me wrong, these green leafy vegetables aren’t good for nothing and can be used in some healthy ways.
I find that cooking leafy greens in a liquid, discarding the leaves while straining the clear “broth”, and using that clear mineral filled broth as you would for any other type of base broth can be quite useful.
In my opinion, “antinutrients” like glucosinolates and oxalates, which are found in vegetables, are in high enough quantities that pure “green juices” should not be consumed and instead juices composed of only fruits should be consumed. While the act of juicing the vegetable frees the nutrients from the cellulose, I don’t believe the pro’s outweigh the con’s when the issue of nutrients vs “antinutrients” in the vegetables juice is considered.
To illustrate this better, author Tim Ferriss and Chris Young have a conversation in this short clip about how “vegetables want to kill you”. Chris Young has a background in biochemistry, mathematics and has also worked as a chef in the past.
After hearing that, one might wonder how an animal like a cow can graze on grass all day and not experience these negative effects, but ruminant animals (animals who have 4 stomachs like a cow) have specialized digestive systems which allow fiber, starch, sugar, and proteins to be fermented by microbes, thus allowing those nutrients to then be used. Non-ruminant animals (like us) have a very small gut and don’t have the ability to do this like a cow or other ruminents, which leave us experiencing many negative digestive consequences (foul gasses included).
Now an argument one might make for keeping leafy greens and other vegetables in the diet is that antinutrients actually have a hormetic effect in the body.
In biological terms, hormesis is the idea that small amounts of stress actually make the organism stronger because of adaptive responses. More specifically the argument is that these plant hormetic compounds are actually biologically stressful on the cell and they trigger cellular stress response pathways that are actually beneficial because the cells over respond to the otherwise slightly toxic substances.
I do not agree with this idea when speaking about nutrition. Health coach and independent health researcher Jay Feldman dives deep into this subject in the two links below and debunks this idea of hormesis very effectively. If you’re interested in the subject of hormesis in nutrition, I highly recommend you give them a read:
Part 1: https://jayfeldmanwellness.com/hormesis-part-1-does-stress-make-you-stronger/
Here’s a quick excerpt from part 2:
“…At best, the hormesis research suggests that stress builds tolerance to stress and that, rather than improving our health, this stress tolerance reduces our ability to function on a high level” …and that… “stressors and damage that drain the energy pool and increase ROS production result in adaptations that are NOT ideal for the long-term health of the organism.”
Another way of looking at this is that our cells are actually already under constant “attacks” from stress at any given moment. There could be thousands of different factors that are stressing our cells at all times and to add more stresses on top of that is not helpful. Ideally, you want cellular stress to be minimal. While this idea may sound very simplistic, I can’t stress enough the importance of reading Jay’s hormesis breakdown for a more in depth look at the subject.
After everything is considered, I believe consuming raw vegetables, large amounts of vegetables, or vegetable juices is not ideal. Instead, getting your vitamins and minerals from nutrient dense foods that only have a positive effect on your metabolism like fruit, fruit juices, beef liver, oysters, eggs and coffee would be a much wiser choice in my opinion.
Another broad, general term for these defense chemicals when thinking about human nutrition could be “antinutrients”. Some of these toxins or antinutrients include certain phenols, tannins, lectins/agglutinins, trypsin-inhibitors, along with an innumerable amount of other metabolic inhibitors. Unsaturated fats themselves are important defenses, since they inhibit trypsin and other proteolytic enzymes, preventing the assimilation of the proteins that are present in seeds and leaves. This disrupts all biological processes that depend on protein breakdown, such as the formation of thyroid hormone and the removal of blood clots.
While most of these defense chemicals don’t cause an obvious acute reaction (although some do like poison ivy), these chemicals slowly affect their attacker over months, years and generations.
I think nutrition researcher Georgi Dinkov summarized this subject terrifically in a post which you can read here:
“The goal of most plants is to have as many of their seeds spread as far as possible. Thus, plants often encapsulate seeds in appetizing wrapper to entice organisms to ingest the seeds. At the same time the seeds contain substances that would inhibit the ability of this organism to digest (destroy) those seeds. One of the most commonly used substances by the plants are the oils found in the seeds. Seed oils happen to be a powerful suppressor of both digestive and metabolic activity (the two are closely related). Most vegetable oils sold on the market are extracted from seeds (sunflower, cottonseed, canola, rapeseed, soybean, peanut, etc), and as such are likely to suppress both metabolism and digestion. In addition, many of the seeds contain toxic substances based on the well-known poison cyanide to further discourage organisms from attacking/eating the seeds. (Pro)anthocyanidins and some of the most common cyanide-derived poisons are found in virtually all seeds.
https://en.wikipedia.org/wiki/Proanthocyanidin#Biological_significance
As a general rule, the seeds of a plant contain the most powerful toxins and should be avoided as food unless there is nothing else available. In contrast, olive oil and coconut oil are extracted from the actual fruit and not from seeds. I guess another distinction is that both olive and coconut oil are actually fruit oils and not vegetable oils. The fruit is typically meant to be eaten as a means of spreading the seeds and usually contains beneficial substances like sugars and pro-metabolic oils.
The vegetable plant, as opposed to the seeds, is usually less toxic when eaten but it is still very difficult to digest (most plants are mostly cellulose and water) and it is usually not very calorie-dense. Given our large brains and daily caloric demands, it just does not seem likely that vegetables (and derivative oils) are the food we are supposed to eat the most.”
Cellulose is an insoluble substance and is the main structural component of plant cell walls and vegetable fibers. It is a polysaccharide (a type of carbohydrate) consisting of chains of glucose. Here you can see more a visualization of what cellulose actually looks like:
Humans cannot digest cellulose because they lack the enzymes essential for breaking the beta-acetyl linkages.
Now if you did choose to include plants in your diet, one of the reasons you would want to cook the plants well is because of this cellulose. Think of cooking plants as a predigestion of sorts. Not only will you digest them better after cooking, but you will be utilizing more of the nutrients within the plant after the cellulose has been broken down and the nutrients have been “freed” from the plant’s cell walls. Remember, the fruit of the plant should typically be eaten in its raw state but the stem, leaves and root of a plant are better off cooked. Not to be crass, but if you’ve ever eaten a large salad full of raw vegetables and leafy greens like kale, later on or the next day you will be able to tell that most of it wasn’t fully digested. Not to mention all the gas and uncomfortable bloating you might experience after as well.
And speaking of kale, this green leafy vegetable must have a great PR team. I hear nothing but talk about kale and kale juice in the health circles these days. It seems to be the craze lately and I think I might have a good idea why…
The first time I had ever heard of kale being talked about as a food (and not as the that green leafy decoration that is typically used to put around buffets) was the year 2008. I had read a book by Dr. Joel Fuhrman called “Eat for Health” and in it he had devised a system that would rank foods based on their nutritional content in contrast to how many calories a food had. In other words, the foods with the most nutrients and the least amount of calories would get the highest score. The nutrients he included in this formula were: fiber, calcium, iron, magnesium, phosphorus, potassium, zinc, copper, manganese, selenium, vitamin A, beta carotene, alpha carotene, lycopene, lutein and zeaxanthin, vitamin E, vitamin C, thiamin, riboflavin, niacin, pantothenic acid, vitamin B6, folate, vitamin B12, choline, vitamin K, phytosterols, glucosinolates, angiogenesis inhibitors, organosulfides, aromatase inhibitors, resistant starch, resveratrol plus their ORAC score. He called this the Aggregate Nutrient density Index (or ANDI for short). Foods would be ranked on a scale of 1-1,000, with 1,000 being best. Well it turned out kale was at the very top of that list with a score of 1,000. After seeing that I headed straight to the grocery store to load up on my kale and attempted to include it in every meal I could.
So I must have become superman shortly thereafter right?
Not exactly.
I started experiencing bloating, digestive issues, a reduction in energy levels, bad insomnia, irritability, changes in the quality of my teeth, hair and nails, etc. Plus it just flat out didn’t taste great. Yeah I could dump a bunch of dressing on a kale salad but that defeats the purpose of whatever health benefits I may have been attempting to attain with kale.
I tried other foods that made the top of his list but I had the all same negative experiences again.
Looking back now it’s so incredibly clear what the problem was:
Dr. Fuhrman didn’t take into account the large amount of antinutrients that come with green leafy vegetables.
The diet is full of raw vegetables and wreak havoc on digestion (granted some in the book are recommended to be cooked).
He is so focused on micronutrients that he forgets nutrition is MUCH more than micronurients. Hence the name MACROnurients, which are larger players in the nutrition world.
I don’t believe he understands the value of macronutrients (protein, fat and carbohydrate). For example, fructose (a type of simple sugar) stimulates the liver to turn the thyroid hormone T4 into T3 which increases the metabolism, in turn massively increasing the production of carbon dioxide. This increase in carbon dioxide allows the body to use vitamin K to a much greater degree.
He missed some extremely potent nutrients. Something like naringin has strong anti-inflammatory and antioxidant activities and that was not included in his list.
Some micronutrients he touted as healthy are actually quite anti-metabolic which I would not recommend consuming (like beta carotene, a precursor of retinol). In my opinion, getting retinol directly is much more metabolically friendly. Perhaps these types of misconceptions can be an article of their own in the future.
The calorie itself in a nutrient. Yes, obesity is an issue in the Western world, but many people suffer from illnesses that can worsen when someone is underweight. There’s even something called “the obesity paradox” where those who are slightly overweight tend to live longer than those who are underweight. You can read about that here: https://pubmed.ncbi.nlm.nih.gov/29981771/
To be honest, the list could go on and I think this philosophy of health Dr. Fuhrman devised was a very poor one.
I think this chart below which I had posted in one my earlier articles would be very helpful when considering micronutrients and how they play just a part of the picture—and not nearly the whole picture when health is considered:
In my opinion, so many in the field of nutrition disagree simply because of context.
I don’t think the baby should be thrown out with the bathwater though, I think these green leafy vegetables and vegetables of all sorts can be used in healthy ways. I find that cooking leafy greens well, having them in a broth, or simply being used to make a broth and discarding the vegetables all are methods you can use in a beneficial way. Even a clear broth made from vegetables will be fairly rich in minerals.
In my opinion, “antinutrients” like glucosinolates and oxalates, which are found in vegetables, are in high enough quantities that pure “green juices” should not be consumed and instead juices composed of only fruits should be consumed. While the act of juicing the vegetable frees the nutrients from the cellulose, I don’t believe the pro’s outweigh the con’s when the issue of nutrients vs “antinutrients” in the vegetables juice is considered. Juicing fruit is a great option though and it’s something I do myself.
After hearing that, one might wonder how an animal like a cow can graze on grass all day and not experience these negative effects, but ruminant animals (animals who have 4 stomachs like a cow) have specialized digestive systems which allow fiber, starch, sugar, and proteins to be fermented by microbes, thus allowing those nutrients to then be used. Non-ruminant animals (like us) have a very small gut and don’t have the ability to do this like a cow or other ruminents, which leave us experiencing many negative digestive consequences (foul gasses included).
Now an argument one might make for keeping leafy greens and other vegetables in the diet is that antinutrients actually have a hormetic effect in the body.
In biological terms, hormesis is the idea that small amounts of stress actually make the organism stronger because of adaptive responses. More specifically the argument is that these plant hormetic compounds are actually biologically stressful on the cell and they trigger cellular stress response pathways that are actually beneficial because the cells over respond to the otherwise slightly toxic substances.
I do not agree with this idea when speaking about nutrition. Health coach and independent health researcher Jay Feldman dives deep into this subject in the two links below and debunks this idea of hormesis very effectively. If you’re interested in the subject of hormesis in nutrition, I highly recommend you give them a read:
Part 1: https://jayfeldmanwellness.com/hormesis-part-1-does-stress-make-you-stronger/
Here’s a quick excerpt from part 2:
“…At best, the hormesis research suggests that stress builds tolerance to stress and that, rather than improving our health, this stress tolerance reduces our ability to function on a high level” …and that… “stressors and damage that drain the energy pool and increase ROS production result in adaptations that are NOT ideal for the long-term health of the organism.”
Another way of looking at this is that our cells are actually already under constant “attacks” from stress at any given moment. There could be thousands of different factors that are stressing our cells at all times and to add more stresses on top of that is not helpful. Ideally, you want cellular stress to be minimal. While this idea may sound very simplistic, I can’t stress enough the importance of reading Jay’s hormesis breakdown for a more in depth look at the subject.
After everything is considered, I believe consuming raw vegetables or raw vegetable juices is not ideal. Instead, getting your vitamins and minerals from nutrient dense foods that only have a positive effect on your metabolism like fruit, fruit juices, beef liver, milk, cheese, oysters, eggs and coffee would be a much wiser choice in my opinion.
Here’s what you can do though if you enjoy vegetables from time to time like I do you can do:
Cook vegetables well if you would like to include them in your diet. Doing so will make the nutrients they contain more bioavailable and make them much easier to digest. Cooking the vegetable is also going to "turn off" a lot of the potentially detrimental substances found in raw vegetables and greens like goitrogens. Well cooked broths which include kale, spinach and other greens and vegetables can be a good option as well for nutrients like calcium, potassium, vitamin K.