Anti-Nutrients: Nature’s Chemistry, Not the Enemy

The internet loves a villain. In one corner: “anti-nutrients” — lectins, oxalates, phytates, phytoestrogens, the boogeymen of beans and greens. In the other corner: butter-coffee, bacon, raw liver, and beef tallow fried in cast iron like a sacrament.

But step back for a second. Plants are the most consumed substances on Earth after water. They have been feeding mammals, insects, fungi, and microbes for hundreds of millions of years. They built our cells, fed our microbiome, and trained our liver. We are not strangers to plants; we are continuous with them in a closed carbon loop.

For ~60 million years, our primate ancestors experimented with leaves, shoots, roots, tubers, fruits, seeds and bark. We used plants as food, medicine, poison, buzz, and hunting aid. If they truly “didn’t want us to eat them”, they failed spectacularly.

Did you know? Almost every major drug class — painkillers, chemo agents, heart medicines — has root inspiration in plant defence chemistry. The same “toxins” we fear in lentils inspired aspirin, digitalis, taxol, and more.

1. What People Mean by “Anti-Nutrient”

“Anti-nutrient” is not a villain class in biochemistry. It’s a nickname for plant compounds that can reduce the absorption of some nutrients under certain conditions, or irritate sensitive guts in high doses. Think:

Proteins that stick to sugars (lectins).
Molecules that bind minerals (phytates, oxalates).
Plant hormones that lightly dock to our receptors (phytoestrogens).
Fibres that microbes eat first, not us.

But here’s the thing: the same compounds that “block” or “bind” in one context protect and modulate in another. They chelate excess iron, slow sugar spikes, feed gut bacteria, or trigger adaptive stress responses that make cells more resilient.

Suggested diagram: Two-panel flowchart.
Left: “Anti-nutrient as villain” → arrows to “blocked minerals”, “upset stomach (in some)”.
Right: “Anti-nutrient as ally” → arrows to “antioxidant”, “cancer protection”, “stable blood sugar”, “microbiome fuel”.

2. Nightshades: Spices, Solanine & Selectivity

Tomatoes, potatoes, peppers, aubergines — the nightshade family. Yes, they contain alkaloids like solanine and capsaicin. Yes, in raw, green, or massive doses some can irritate. But:

Traditional cultures cook, ferment, soak, peel and don’t eat green potatoes.
Capsaicin, the “go away” signal for mammals, became a human pleasure signal — spice.
Many nightshade compounds have anti-cancer, anti-inflammatory, and metabolic benefits at normal doses.

Did you know? Birds are mostly insensitive to capsaicin. Some peppers “wanted” birds to spread their seeds, not mammals — we crashed the party and decided we liked the burn.

Suggested graph: Bar chart of typical solanine intake from cooked potatoes vs known toxicity threshold. Show how everyday exposure sits far below danger in healthy people.

3. Lectins: Sticky Proteins Meet Fire, Soaking & Microbes

Lectins are proteins that bind carbohydrates. Raw kidney beans can make you very sick because of high phytohaemagglutinin. That’s real. But:

Soaking + boiling for ~10–15 minutes denatures the lectin almost completely.
Traditional cuisines independently invented soaking, sprouting, fermenting to tame legumes.
Once cooked, beans become one of the strongest predictors of longevity in population studies.

Suggested diagram: “Raw bean → Soaked → Boiled → Fermented” with a curve showing lectin activity dropping while fibre, protein, and micronutrients remain.

4. Oxalates & Phytates: Handcuffs and Bodyguards

Oxalates and phytates can bind minerals like calcium, iron and zinc. This is why they’re called “anti-nutrients”. But they also:

Help prevent excess free iron from driving oxidative stress.
Act as antioxidants and chelators for heavy metals.
Are reduced by boiling, steaming, fermenting, sprouting.

Kidney stones? Most stones are calcium oxalate, but risk shoots up with:

High animal protein and salt, low fluid intake.
Genetic sensitivity, specific gut microbiome patterns.

Spinach is indeed high in oxalate. Some people need to limit it. But kale, bok choy, many lettuces and crucifers are far lower. The story isn’t “plants are dangerous”; it’s “some individuals + specific plants + context”.

Did you know? In populations with high legume and whole-grain intake, iron deficiency isn’t inevitable — because the same diets also bring vitamin C, fermentation, and gut microbes that increase mineral absorption over time.

Suggested chart: Two stacked bars for “Kidney stone risk”: Bar 1: “High meat + low fluid + low veg”. Bar 2: “Moderate veg (incl. spinach) + high fluid + lower meat”. Show risk higher in the first, despite lower vegetable oxalate.

5. Phytoestrogens vs Real Hormones: Soy, Beer & Milk

“Phytoestrogen” sounds terrifying — as if tofu is smuggling birth-control pills. In reality:

Soy isoflavones are weak, selective modulators of estrogen receptors.
In many contexts, they block stronger estrogens and can lower risk of certain cancers.
Traditional soy foods (tofu, tempeh, miso) come with fibre, minerals and fermentation.

Meanwhile:

Beer, especially hopped beer, contains potent plant estrogens from hops.
Dairy from pregnant cows can contain actual mammalian sex hormones.

“Don’t touch thermal receipts, bro, they have endocrine disruptors!”
— says the same culture that drinks a litre of cow’s milk a day and chases it with beer.

6. Fibre: The Forgotten Macromolecule

Fibre is sometimes framed as “anti-nutrient” because we can’t digest it. That’s the point. Our microbes can. They turn fermentable fibres into short-chain fatty acids (like butyrate) that:

Feed colon cells.
Regulate immune function and inflammation.
Influence blood sugar and appetite.

Fossilized human feces suggest ancient diets carried tens of grams of fibre per day, easily 50–80g in some groups. Modern industrial diets average under 20g. Our colons and microbiomes remember a different world.

Suggested chart: Line graph: “Estimated ancestral fibre intake (50–80g+)” vs “Modern Western intake (~15–20g)”. Overlay markers for “colon cancer”, “diverticular disease” rising as fibre drops.

7. “Plants Have Toxins” — So Do Animals

A common meme: “Plants don’t want to be eaten, so they have toxins. Meat is clean.”

But animal flesh is not a neutral blank slate either. It can carry:

Endotoxins from bacteria in the gut and blood.
Stress hormones and inflammatory signaling molecules at slaughter.
Protein fragments that can trigger immune reactions in susceptible people.
Pathogens like E. coli, Salmonella, Campylobacter, parasites.

Raw liver, tartare, undercooked chicken? For carnivores with pH ~1 stomach acid and ultra-short guts, that’s Tuesday. For humans with stomach pH closer to 3–4 when fed and a long, winding intestine, that is hospital time for a non-trivial number of people every year.

Did you know? Many carnivores prefer carrion. A big cat will happily eat a days-old carcass. Humans invented fire, spices, refrigeration, vinegar, lemon juice and “best before” dates precisely because we are not that animal.

We won’t take our kids to a slaughterhouse field trip — but a bear or lion would treat it like Disneyland and roll in the entrails.

8. Seed Oils vs Tallow: The “Natural” Trap

New internet gospel: “Seed oils are toxic. Fry in butter, ghee or beef tallow instead.”

Let’s be honest about process:

To get clear vegetable oil, you press, filter, sometimes refine and deodorise.
To get jars of beef tallow or lard, you render fat at high heat, separate, cool, sometimes bleach and deodorise.

Both are processed extractions of pure energy from whole foods. Neither is how any wild animal meets fat in nature.

Suggested comparison graphic: Two flow diagrams. Olive → crush → press → settle → bottle. Beef → slaughter → trim fat → render in vats → filter → pack. Caption: “Both are processed. ‘Natural’ is a marketing word, not a chemical term.”

Polyunsaturated fats (PUFAs) from whole seeds, nuts and fish are easily used by the body and woven into membranes and signaling molecules. They are more fragile to heat and oxidation, which means they should be respected in the kitchen but not feared in a walnut.

Saturated and trans fats are more heat-stable — and that’s part of the problem. In excess and over time they are strongly linked with:

Elevated LDL cholesterol and altered lipoprotein profiles.
Inflammation, insulin resistance and endothelial dysfunction in some people.
Higher risk of heart disease when they displace unsaturated fats and fibre-rich foods.

“Don’t fry your steak in seed oils, that’s toxic!” “Fry it in butter and tallow instead, that’s natural.”
You had to render, heat, clarify, and concentrate both. They are both industrial abstractions of calories. The body cares about dose, pattern, and context — not our hashtag.

9. ALA → EPA/DHA: “Low Conversion” or “Enough for What We Need”?

Another common narrative: “Plant omega-3 (ALA) is useless because conversion to DHA is low. You must eat fish or animal brain/fat.”

More accurate:

We only need small absolute amounts of EPA/DHA.
ALA from flax, chia, walnuts can convert to EPA/DHA at a few percent — which is enough for many people, especially when overall diet is balanced.
Along the way, ALA participates in making resolvins and protectins, molecules that actively resolve inflammation.

Pre-formed DHA from fish or algae can be helpful in some situations — pregnancy, deficiency, certain brain conditions — but is also more oxidation-prone in supplement form. Converting on demand from ALA is not a bug; it’s a regulation feature.

10. Iron: Bioavailable vs Bypassing the Safety Rails

Heme iron from meat is often marketed as “highly bioavailable” — which sounds purely positive. It also means:

It can be absorbed even when the body is trying to dial iron down.
Excess heme iron has been linked with oxidative stress and higher risk of some chronic diseases in some populations.

Non-heme iron from plants is more tightly regulated: absorption increases when you’re low, and decreases when you’re full. Vitamin C, fermentation and the microbiome can boost its use.

Again, the point isn’t “meat bad, plants good.” It’s that “bioavailable” sometimes means “bypasses safety rails”, and that the story depends on who you are, what you eat with it, and how much over decades.

11. The Bigger Pattern: Humans Are Chlorophyll Made Curious

We and the plants share a closed carbon and nitrogen system:

Plants take CO₂, water, minerals and light → build glucose, amino acids, fats.
Animals eat plants (or plant-eating animals) → rearrange those molecules, don’t invent new ones.
We exhale CO₂, shed nitrogen, return minerals to soil → plants start again.

When someone says, “We’re flesh so we must eat flesh to get what we need,” they’re skipping the step where all of that flesh was once plant. If you insist that you must eat an animal because it’s “made of what you’re made of,” the more logical end-point is uncomfortable: that’s an argument for cannibalism, not nutrition science.

We are not separate from plants. We are a downstream expression of their chemistry — a mobile branch of the chlorophyll experiment that learned to hold a mirror, ask questions, and rename plant defence molecules as “anti-nutrients” because it forgot the story.

Suggested diagram: “Sun → Leaf → Glucose & Amino acids → Animal → Human Brain”. A looping arrow returns “CO₂, nitrogen, minerals” back to soil and air. Caption: “Closed carbon cycle, open imagination.”

12. How to Actually Think About “Anti-Nutrients”

Instead of “this molecule is toxic, avoid all plants,” ask:

What dose? Spinach by the handful vs spinach powder by the scoop.
What preparation? Raw vs cooked, soaked, sprouted, fermented.
What person? Healthy kidney vs stone-former, celiac vs non-celiac.
What pattern? A varied plant-rich diet vs a mono-food obsession.

Can you see the pattern? The same “anti-nutrients” people fear are regularly linked with lower cancer, heart disease, and mortality when eaten as part of traditional, plant-rich diets. Context beats clickbait.

Fear sells. But biology runs on nuance. Plants are not perfect, but neither are we. Together, across millions of years, we’ve negotiated a truce:

They defend themselves just enough to survive.
We cook, soak, ferment and season just enough to thrive.

Nightshades, lectins, oxalates, phytates, soy isoflavones, fibre — they’re not curses from a hostile nature. They are parts of a shared chemical language between roots, microbes, animals and us. Learning to read that language beats burning the library down.