Stop Cooking With These: A Longevity Physician’s Guide to Seed Oils & Saturated Fat

We’ve been told the same story for 50 years: "Saturated fat is bad, vegetable oil is heart-healthy." But if that’s true, why are we in a global energy cri…

Published January 17, 202614:22The Longevity Show

The seed oil argument online has two camps: one insists cholesterol is the only thing that matters, the other that seed oils are poison and butter is a health food. Dr. Lin's position is that both are oversimplifying, and this episode is the case for standing in the middle without being vague about it.

The organising idea is that a heart attack needs two things, not one — a particle to lodge in the artery wall, and an environment oxidising enough to make it rot. Lower the particle count and ignore particle quality and you still carry risk; perfect the environment and keep ApoB high and you still carry risk. That framing is what separates this from most seed-oil content, and it is why the practical advice ends up less absolutist than either camp.

From there it gets specific: why smoke point is close to useless as a safety guide, why the mitochondrial membrane composition question may matter more than the arterial one, and a tiered list of what to actually cook with. Several claims here sit on emerging rather than settled research, and Dr. Lin flags which is which as she goes.

Before you watch

Heart disease needs both the particle and the environment. You need an ApoB-carrying particle to lodge in the artery wall and enough oxidation for it to rot and trigger the immune response that forms plaque. The practical implication is to manage both — keep ApoB reasonable and build particles out of more stable fats — rather than betting everything on one lever.
Smoke point is the wrong metric for choosing a cooking oil. It measures when an oil becomes visibly smoky, not when it starts degrading. Grapeseed oil has a high smoke point but, being polyunsaturated, generates aldehydes before it ever smokes. Extra virgin olive oil smokes lower but its polyphenols sacrifice themselves to protect the fat, staying chemically stable to around 350–375°F.
The mitochondrial argument is the more interesting one. Cardiolipin, the phospholipid that holds the inner mitochondrial membrane's folds in shape, is built from the fats you eat. Built largely from linoleic acid it becomes more prone to peroxidation, producing 4-HNE — which newer work suggests acts as a signalling molecule rather than inert waste. Treat this as an emerging mechanism, not settled clinical fact.
Coconut oil is not the universal high-heat answer. It holds up for baking but degrades in deep frying — via hydrolysis from moisture in the food rather than oxidation. Tallow, rich in stearic acid and chemically stable, is the better searing and frying fat.
Ghee is good but should not be reused. Removing the milk solids pushes the smoke point to around 485°F, but ghee still contains cholesterol, and repeatedly heating cholesterol produces oxidation products that are not something you want in your arteries. Fry with it once, then discard.
Air fryers are an oxidation accelerator by design. They blast hot, oxygen-rich air past a thin film of oil, which is close to worst case for an unstable fat. If you use one, pair it with a stable fat such as tallow, ghee or verified avocado oil.
Buy avocado oil carefully or not at all. A UC Davis analysis found roughly 82% of avocado oils on shelves were rancid or adulterated, so brand verification matters more here than in almost any other category — otherwise you may be paying a premium for degraded soybean oil.
The tiers, as Dr. Lin uses them: extra virgin olive oil, tallow and cultured algal oil as the stable core; verified avocado and high-oleic sunflower as acceptable with caveats; soybean, corn, canola, cottonseed and standard sunflower as the ones to displace first.
Eating out, the fryer is the thing to avoid, not the dressing. Oils held hot for days polymerise. Dr. Lin's own rule is not to worry about the oil in a salad dressing but to treat fries and tempura as the genuine exposure.

Chapters

00:00

The Official Protocol: Tier 1, 2, and 3 Oils for Your Kitchen

Questions

Are seed oils actually poison?

No, and Dr. Lin is explicit that the camp saying so is oversimplifying as badly as the camp that says only cholesterol matters. The argument in this episode is narrower: oils high in linoleic acid are chemically less stable, which matters for what your cell membranes and LDL particles get built from, and matters more again when those oils are heated hard or repeatedly. That is a case for displacing them from your cooking, not for treating a salad dressing as a toxin.

What should I actually cook with at high heat?

Tallow for searing and frying — it is high in stearic acid and chemically stable. Extra virgin olive oil covers roughly 90% of ordinary cooking and stays stable to about 350–375°F despite its lower smoke point, because its polyphenols protect the fat. Ghee works but should not be reused. Coconut oil is fine for baking and poor for deep frying.

Isn't a high smoke point what makes an oil safe for cooking?

That is the assumption this episode argues against. Smoke point only tells you when an oil becomes visibly smoky — it says nothing about the chemistry. Grapeseed oil scores well on smoke point and still generates toxic aldehydes before it smokes, an invisible degradation. Stability under heat, driven largely by how polyunsaturated the oil is and whether it carries protective antioxidants, is the more useful property.

Is avocado oil a safe choice?

Only if you verify the brand. A UC Davis analysis found around 82% of avocado oils tested were rancid or adulterated, which means the label is unusually unreliable in this category. Dr. Lin deliberately does not publish a brand list because it changes constantly — the recommendation is to check current third-party testing before buying rather than trusting the bottle.

Could cooking oil have anything to do with my headaches or joint pain?

Possibly, though this is emerging rather than established. An NIH-funded trial in people with chronic migraine changed only dietary fat — cutting linoleic acid to about 2.5% of calories while raising omega-3s — and saw a significant reduction in headache frequency and severity. The proposed mechanism is that linoleic acid oxidises into metabolites that activate TRPV1, the same receptor that makes chilli feel hot, producing a low-grade increase in pain sensitivity. Worth knowing about; not a substitute for working up an unexplained symptom with your clinician.

The Longevity Letter