The guide

Oils in the kitchen

By GyroscopeUpdated November 14, 202611 sources

Use extra virgin olive oil for most cooking, frying and dressing, and a neutral oil such as canola for baking and dishes where you want no olive taste. Keep butter, ghee, tallow and coconut oil for flavor, since one tablespoon of any of them fills a quarter to a half of a day’s saturated fat line.

Picking an oil has turned into a fight with three sides. One says never heat olive oil because its smoke point is low. Another says seed oils turn toxic in the pan. A third says the healthy choice is coconut oil, avocado oil or beef tallow. Each one takes a single number, usually the smoke point, and treats it as the whole story.

There are really three separate questions. What fats are in the oil, which decides what it does to your LDL. When it starts to smoke. And how well it holds up over a long time in heat, which is the one that decides what ends up in your food.

What’s in a tablespoon?

Here are 13 cooking fats, a tablespoon each, sorted by saturated fat. The share is of a 22 g line, which is 10% of a 2,000 calorie day.

• Saturated
• Monounsaturated
• Polyunsaturated
• Trans

The top five are solid on a cool counter and the rest pour, which is the shape of the chains showing (see the four fats). Coconut oil is the outlier people don’t expect. It’s about 83% saturated, more than butter at about 62%. In 16 trials, coconut oil raised LDL compared with other plant oils, and it didn’t change blood sugar, inflammation or bodyfat. Ghee is butter with the water and milk solids cooked off, so it’s the same fat, a little more concentrated.

The oil compare puts any two of these side by side, against your own line.

Does smoke point matter?

Smoke point tells you less than the internet thinks. The best test we have of how oils behave in heat comes from one lab, and it’s an olive oil company’s lab, Modern Olives Laboratory Services in Australia. The paper names the lab, and its results don’t flatter every olive oil, since virgin olive oil smoked earliest of all ten.

In 2018 they bought ten common oils from Australian supermarkets and measured each one’s smoke point, the temperature where a steady blue smoke appears.

Then they held 3 liters of each oil in a deep fryer at 356 °F (180 °C), which they call the highest temperature recommended for deep frying, for 6 hours. They measured the polar compounds, the breakdown products that build up in frying oil, as it went.

After 6 hours, sunflower oil had reached 21.8% polar compounds, grapeseed 20.2%, canola 17.3% and rice bran 15.7%. Extra virgin olive oil was at 10.5% and coconut oil at 9.7%. In a second test they heated each oil in a pan from room temperature to 464 °F (240 °C) over about 20 minutes, and canola reached 27.5% polar compounds, past the 24 to 27% that many countries allow in frying oil, the authors note.

Here are the ten oils ranked by their average over both tests.

The authors’ own conclusion was that “smoke point does not predict oil performance when heated”. The oils that smoked latest, the refined seed oils high in polyunsaturated fat, broke down the most.

Coconut oil did well in the pan because it’s mostly saturated, and saturated chains have no kinks to attack. Its problem shows up at the table, in your LDL. Extra virgin olive oil did well with mostly monounsaturated fat and its own natural antioxidants, the authors say.

The test has limits. No food was cooked, and the authors point out that water and steam from real food change what happens in the oil. It was also one lab and one set of bottles.

Should you cook with extra virgin olive oil?

Yes, for most cooking, frying included. In that test it smoked at 404 °F, above the 356 °F used for deep frying, and averaged over both heat tests it made the fewest breakdown compounds of all ten oils. Virgin olive oil, one grade below extra virgin, smoked much earlier, at 348 °F, so the grade on the label counts.

The heat that does the most damage is long and repeated. Every oil in the test built up more breakdown products the longer it was heated, and the authors note that an oil’s smoke point drops as it’s used. Frying in the same oil night after night is the part to avoid, whatever the oil. You shouldn’t cook with olive oil has the full myth.

How do you know your olive oil is real?

The fridge won’t tell you. In February 2013 a daytime TV health show told viewers that pure extra virgin olive oil would solidify in the refrigerator. People tried it, their oil stayed liquid, and they complained to the producers and shops.

The UC Davis Olive Center tested the claim with seven oils in a lab refrigerator at 40.5 °F (4.7 °C). After 60 hours nothing had changed. After five days the oils that were at least half virgin olive oil had started to set at the bottom, and none ever fully solidified. The team called the fridge test unreliable for judging purity or quality.

Their advice is more useful. Choose an oil within 15 months of its harvest date, which is a different date from the best before date. Look for a seal showing it passed chemical and taste testing. And buy oil kept out of the light.

What happened to the advice against canola?

You’ll still hear that you should avoid canola and corn oil and cook with olive or coconut oil instead. The trials point the other way on coconut oil. The 2020 to 2025 US Dietary Guidelines named canola, corn, olive, peanut, safflower, soybean and sunflower oils as the ones to cook with “rather than butter, shortening, or coconut or palm oils”.

In a study that followed 221,054 US adults for up to 33 years, more canola, soybean and olive oil each went with fewer deaths. Canola has only 1.0 g of saturated fat a tablespoon, which makes it a good swap for butter in baking and in dishes where you want a neutral taste. Its weak spot is high heat. Averaged over both heat tests, it made the most breakdown compounds of the ten oils, so fry with olive oil instead. Are seed oils bad for you? goes claim by claim.