A Doctor's Theory of Why Modern Food Is Making Us Sick

Physician Zach Bush spent seventeen years developing chemotherapy in academic labs before walking away from it to work on regenerative agriculture. On episode #2529 of The Joe Rogan Experience, he lays out why: a theory that traces modern chronic disease back to one molecule and a broken relationship with soil. Two stretches of the episode carry the argument. This one picks up the glyphosate origin story:

And this one, from the closing stretch, walks through the disease cascade he thinks it's caused:

Bush trained as a physician in internal medicine, endocrinology and hospice care, then spent years developing chemotherapy in academic labs before walking away from it. His pitch now runs through Farmer's Footprint, a regenerative-agriculture nonprofit he founded, and a new book called Biological Elegance, sold only through his own site rather than Amazon. The core claim: modern chronic disease isn't a collection of unrelated conditions. It's one condition, expressed differently depending on which system gives out first.

The molecule at the centre of it

The chemical he keeps circling back to is glyphosate. Its actual history is a bit less tidy than the version he tells on the podcast, but the shape of it holds up. It started life in the early 1960s as an industrial descaling agent, patented to strip mineral buildup out of pipes and boilers. A Monsanto chemist, John Franz, found it also killed plants, and the company patented it as a herbicide in 1970. Roundup went on sale under Monsanto in 1974, and by the mid-1990s, glyphosate-tolerant "Roundup Ready" crops had turned it into the most heavily used herbicide on the planet. Somewhere near 90% of the world's glyphosate has been sprayed in the last decade alone.

Bush's argument is that glyphosate doesn't just kill weeds. It's a chelator, meaning it grabs onto minerals and locks them up, and it disrupts a bacterial pathway that plants share with the microbes living in human and animal guts. Spray it on a paddock and you're not just clearing weeds, you're thinning out the soil's microbial life. Eat food grown in that soil, or food carrying trace residues, and the same mechanism goes to work on your own gut flora and, by his account, on mitochondrial function inside your cells.

Whether that single mechanism can carry the full weight he puts on it (he lines up obesity, diabetes, allergies, autoimmune disease, neurological conditions and falling fertility rates like dominoes, roughly following the decades since glyphosate's rollout) is a bigger claim than any one podcast conversation can prove. But the individual pieces he's pointing at are real and well documented elsewhere. Gut microbiome disruption is now firmly linked to metabolic, autoimmune and neurological disease, independent of anyone's views on glyphosate specifically. Global fertility has genuinely collapsed faster than almost anyone predicted; 136 countries are now below the replacement rate of 2.1, up from just four in 1950. Something has shifted in the last fifty years. Bush's framework is one attempt, among several competing ones, to explain what.

Bush also leans on Otto Warburg's decades-old observation that cancer cells switch to a different way of generating energy, a metabolic quirk known as the Warburg effect, to argue that cancer is downstream of energy production failing at the cellular level rather than a random invader. It's a real and long-established finding in cancer biology; how far Bush extends it into a broader theory of disease is his own interpretation.

The part that actually matters for how we eat

Strip away the metaphysics and what's left is a fairly practical argument: soil health and human health aren't two separate topics. They're the same system, viewed at different scales. A depleted, chemically managed soil produces food that's nutritionally hollowed out even when it looks fine on a supermarket shelf. A living, biodiverse soil does the opposite, and it does it before a single supplement or fortified product enters the picture.

That's not a new idea to anyone who's spent time around regenerative growers here. It's the same logic behind the shift from organic-as-certification to regenerative-as-practice that keeps coming up in conversations with New Zealand farmers rebuilding soil biology on their own land. Bush just makes the biological mechanism explicit, and connects it all the way up to a human gut.

Where it lands

A physician who spent seventeen years inside the cancer research machine, walked away from it, and now spends his time trying to get farmers back into relationship with living soil, is not a fringe voice by accident. He got there by watching something in the data that didn't add up. Whatever else is on that podcast, the soil argument stands on its own. The two clips above are the ten minutes that make the case.