Seed Oils Alone Might Not Be the Villain. That's Not the Point.
The seed oil fight, as it usually gets fought online, comes down to one question: is linoleic acid inflammatory, yes or no? Pick a side, cite a study, argue in the comments.
I think that's the wrong question, or at least an incomplete one.
There is real, published research on both sides of the linoleic-acid-and-inflammation question. A 2013 BMJ reanalysis of the old Sydney Diet Heart trial, and a 2016 BMJ reanalysis of the Minnesota Coronary Experiment — both by Ramsden and colleagues — found that replacing saturated fat with linoleic-acid-rich vegetable oil was tied to more cardiovascular and all-cause death in those study populations, not less. That directly complicated decades of "just swap to vegetable oil" advice. On the other side, more recent large cohort studies and trial meta-analyses have found the opposite — no clear link between linoleic acid intake and inflammatory markers, and in some cases a lower cardiovascular risk at higher intake. Both bodies of evidence are real. Neither has definitively won. Anyone telling you this is settled science, in either direction, is skipping past a genuine, ongoing dispute among researchers.
But here's what I think gets lost while everyone argues about the molecule: seed oil never shows up alone in the foods actually driving the metabolic health crisis. It shows up bonded to refined sugar, salt, and industrial starch, in ratios specifically tuned by food scientists to be maximally craveable and easy to overeat. Chips, packaged snack cakes, fast food, frozen meals, sauces, dressings — the ultra-processed category almost universally runs on this same combination: cheap oil, cheap sugar, salt, and enough engineering to make stopping at a normal portion genuinely difficult.
That's a different, and I'd argue more defensible, claim than "linoleic acid is toxic." It's not that seed oil in isolation is secretly poisoning you. It's that the modern food supply pairs it with sugar and salt in combinations, and in quantities, that never existed in any traditional diet — and that combination is specifically engineered to override the signals that would normally tell you to stop eating. Rising rates of obesity, insulin resistance, and metabolic syndrome tracked upward alongside seed oil consumption, sure — but they also tracked upward alongside sugar intake, ultra-processed food's share of the diet, and total daily calories, all rising together as the same engineered food products took over the grocery store. Pulling any single ingredient out of that bundle and calling it "the" cause is a hard case to make convincingly. Pulling out the engineering — the deliberate combination and the deliberate overconsumption it produces — is the harder-to-dismiss argument.
That's the actual thesis behind We're Not Sick, We're Being Sold: not that any one ingredient is secretly evil, but that the quantities and combinations showing up in modern food were never chosen for your health. They were chosen because they're cheap, shelf-stable, and difficult to stop eating. Whether linoleic acid itself turns out to be the smoking gun or just one ingredient riding along in the crime scene, the underlying problem — food engineered to be overeaten — doesn't go away either way.
Untangling which parts of your own diet are worth changing first — versus which fights aren't worth having — is exactly what the book's practical section walks through.