Oils and Fats
The single highest-leverage swap in your kitchen.
The frame on which everything else hangs. Get the fats right and half of the longevity work is done before you pick a recipe.
- Extra-virgin olive oil (single-estate, harvest-dated, dark glass)Hydroxytyrosol and oleocanthal — anti-inflammatory polyphenols. Demonstrably moves biomarkers.
- Avocado oilNeutral, high smoke point, low oxidation risk at heat. A legitimate cooking oil.
- Pastured butterHigher fat-soluble vitamins (K2, A, E) than conventional. Kerrygold or local dairy.
- GheeClarified butter, long shelf life, high smoke point, lactose-free.
- Coconut oil (virgin, unrefined)Medium-chain triglycerides, heat stable, neutral flavor when virgin.
- Grass-fed tallow, pastured lardFats humans have eaten for ten thousand years, stable under heat.
- Canola oil, vegetable oilHexane solvent extraction. High omega-6, drives the ratio into the ditch.
- Soybean, corn, sunflower, safflower, grapeseed, cottonseed, rice branSame story. Inflammatory ratio, oxidized in the bottle, in nearly every restaurant meal and ultra-processed food.
- MargarineThe classic seed-oil emulsion. There is no reason to eat this.
- Olive oil labeled 'light' or 'pure'Chemically refined from lower-grade oil. Not the product you think you are buying.
Why this matters
The fats you cook with set the fatty-acid ratio in your cell membranes. That ratio, read out over decades, is one of the most consequential things your plate is doing. The standard American diet runs roughly 20 parts omega-6 to 1 part omega-3. Our ancestral diet was probably closer to 1:1. The gap almost entirely comes from one source: seed oils.
Seed oils entered the American food supply at scale in the early 20th century. They are cheap, bland, and made at industrial scale using hexane solvent extraction — a detail food manufacturers prefer not to advertise. They are in nearly every restaurant meal, nearly every packaged snack, nearly every salad dressing on the shelf. Removing them is half the battle. Replacing them with real extra-virgin olive oil, avocado oil, and pastured butter is the other half.
On real extra-virgin olive oil: the polyphenols that do the anti-inflammatory work (hydroxytyrosol, oleocanthal, oleuropein) degrade in light. Buy it in dark glass. Check the harvest date on the label — if there isn't one, the brand doesn't want you to know how old the oil is. Buy single-estate or at least single-country from a region with a real olive tradition (Spain, Italy, Greece, Tunisia, California). You will taste the difference. Your inflammation markers will respond.
On cooking: every oil on our 'yes' list can handle the heat of normal home cooking. The old rule that you can't cook with olive oil is wrong. Modern testing shows EVOO is remarkably stable up to 400°F due to its polyphenol content — more stable than refined seed oils even at their higher smoke points.