What cooking oils are in your kitchen? Are they the ones you should be using?
The Short Answer
Probably not, if you haven’t audited recently. Most kitchens accumulate cooking oils by habit rather than by design — whatever was on sale, whatever grandma used, whatever seemed healthy at the time. The oil with a large trial behind it is extra virgin olive oil.[1] Making it your default is the whole intervention; the rest is tidying. The oils that should probably go: anything old, rancid, or rarely used.
Something to Sit With
You use cooking oil almost daily. Such a small choice, so frequently repeated, adds up to a significant factor in your overall fat intake.
Is your default oil aligned with what you know about health?
Learn More
Why cooking oil matters. Cooking oil is fat in concentrated form. The type of fat you cook with becomes part of your overall fat intake — and fat type does matter. A dietary pattern high in saturated and trans fats and low in omega-3s is part of what drives chronic inflammation, and the route the review names for saturated fat is NLRP3 inflammasome activation rather than anything more direct — on evidence it calls not always consistent, much of it from in vitro or cross-sectional work.[2]
Because cooking oil is used so frequently, even small improvements in choice compound over time. A better cooking oil is a better default.
The oil hierarchy. Based on current research, here’s a rough hierarchy:
Extra virgin olive oil: Rich in monounsaturated fat and polyphenols, and backed by a large trial. In the PREDIMED trial (~7,500 participants), a Mediterranean diet supplemented with extra-virgin olive oil reduced cardiovascular events by roughly 30%, and each additional 10g per day of EVOO is associated with about 10% lower cardiovascular risk.[1] Note the “extra virgin” part is doing real work: refined or common olive oil showed no significant association in the same analysis.[1] Suitable for most cooking, including moderate-heat sautéing.
Avocado oil: High in monounsaturated fat like olive oil, with a higher smoke point suitable for higher-heat cooking. Less research than olive oil but a reasonable alternative, especially for applications where olive oil’s flavor isn’t wanted.
Butter and ghee: Traditional fats, good for flavor. They’re high in saturated fat, and while the strength of the old blanket warnings has been argued over, saturated fat is part of the dietary pattern this library links to chronic inflammation.[2] Reasonable for occasional use rather than as a default.
Coconut oil: High in saturated fat, primarily medium-chain triglycerides. The health claims have been oversold; it’s not a superfood. Fine in moderation, especially for dishes where coconut flavor is appropriate.
Seed oils (soybean, corn, canola, safflower, sunflower): High in polyunsaturated fats, particularly omega-6. These have become a popular villain, and it’s worth being careful here: the claim that omega-6 oils are directly harmful is contested and not well established. What the evidence does support is that a pattern low in omega-3s is part of the pro-inflammatory picture — the long-chain omega-3s (EPA and DHA) are what your body uses to actively resolve inflammation.[2] So the useful move isn’t fearing seed oils; it’s making olive oil your default because of what’s positively demonstrated about it,[1] and getting enough omega-3.
The audit. Open your cabinet and look at what’s there:
What’s your default oil? The one you reach for most often. Is it a good choice?
How old are these oils? Oil goes rancid. If you’ve had a bottle for more than a year, taste it — rancid oil tastes unmistakably off. Throw out anything questionable.
What’s rarely used? If a specialty oil has been sitting there for two years, you’re not going to use it. Clear the shelf.
What’s missing? If you don’t have high-quality olive oil, get some. It should be your primary cooking fat.
The upgrade path. The simplest intervention:
- Make extra virgin olive oil your default — specifically extra virgin, which is where the evidence sits.[1] Use it for sautéing, roasting, salad dressings, and most applications.
- Keep avocado oil for high-heat cooking if needed.
- Clear out old, rarely used, or rancid oils.
This isn’t about perfection. It’s about shifting the default so that the oil you use most is the one with the trial behind it.
Storage matters. Oils degrade with heat, light, and air exposure. Store oil in a cool, dark place. Buy sizes you’ll use within a few months. Dark bottles protect better than clear ones.
Further reading:
- Estruch R et al., “Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts” (PREDIMED trial)[3] — New England Journal of Medicine, 2018 (corrected republication of the 2013 paper)
- Guasch-Ferré M et al., “Olive oil intake and risk of cardiovascular disease and mortality in the PREDIMED Study”[4] — BMC Medicine, 2014
- Shanahan C, Deep Nutrition[5] — Chapters on cooking fats. A contested perspective: its seed-oil claims go well beyond what mainstream nutrition science supports. Read for the traditional-cooking-fat material, not as settled evidence.
- The Big Fat Surprise by Nina Teicholz[6] — On the history and politics of dietary fat guidance. Also contested — critics argue it’s selective with the evidence — but useful for understanding how the saturated-fat debate got its shape.
Written by AI, directed and approved by me. How this is made →