Is canola oil worse than olive oil?

Extra-virgin olive oil is mechanically pressed rather than solvent-extracted and carries polyphenols that refining removes, and it has the stronger long-term evidence base behind it. That is a genuine difference. It does not follow that canola is harmful — the trials comparing canola against saturated fats favour canola.

Is cold-pressed or expeller-pressed canola better?

It avoids the hexane and the high-heat deodorising step, which addresses the processing objection specifically. The fatty-acid profile is unchanged, so it does not address the omega-6 objection at all. Which matters depends on which argument you find convincing.

Is rapeseed oil the same thing?

In the UK and most of Europe, yes — the same low-erucic-acid crop sold under its older name. Olive Detective treats the two as one entry so a British label and an American one resolve to the same flag.

Does canola oil contain trans fat?

Small amounts form during deodorising, typically well under 1% and below the threshold at which a label must declare it. It is far less than a partially hydrogenated oil contains, and partially hydrogenated oils have been removed from the food supply in the US and EU.

Answer

Is canola oil bad for you?

Short answer

The evidence is contested. Controlled trials consistently show canola oil lowers LDL cholesterol compared with butter or lard, and major health bodies treat it as a heart-healthy fat. Critics object to how it is refined — hexane extraction, bleaching, deodorising — and to omega-6 intake generally. Olive Detective flags canola because many users choose to avoid it, not because a health harm is established.

What canola oil actually is

Canola is a cultivar of rapeseed bred in Canada in the 1970s to be low in erucic acid — the name is a contraction of 'Canadian oil, low acid'. Food-grade canola is required to stay under 2% erucic acid, which is why the old warnings about erucic acid and heart damage, repeated widely online, describe an oil that has not been sold as food for fifty years.

Extraction is industrial. Seeds hold too little oil to press economically, so a hexane solvent pulls it out, and the crude oil is degummed, bleached and deodorised before bottling. Residual hexane in the finished oil is measured in parts per million and regulated, but the process itself is what many people mean when they say the oil is 'industrial'.

The fatty-acid numbers, which cut both ways

Canola is roughly 63% monounsaturated fat, about 19% linoleic acid (omega-6), about 9% alpha-linolenic acid (omega-3), and around 7% saturated fat — the lowest saturated fat of any common cooking oil.

That profile is awkward for both camps. It is not a high-linoleic oil in the way sunflower, safflower and grapeseed are, so the omega-6 argument applies to it far more weakly than to the rest of the seed-oil list. It is also, on paper, closer to olive oil than to the oils it is usually grouped with.

The case against, stated fairly

Refining: solvent extraction plus high-heat deodorising is a long way from cold pressing, and some of that heat generates trans fats in small amounts
Omega-6 balance: the argument that modern diets carry far more omega-6 than the ratio humans evolved with, and that the excess promotes inflammation
Oxidation: polyunsaturated fats degrade under repeated high-heat frying, producing aldehydes — a real finding, mostly studied in commercially reused frying oil
Provenance: most canola is from genetically modified crops, which matters to some people independently of any health question

The case for, stated fairly

Randomised trials and their meta-analyses show canola lowers LDL cholesterol relative to saturated fats
Systematic reviews of controlled feeding studies have generally not found that dietary linoleic acid raises inflammatory markers in humans, which is the mechanism the omega-6 argument depends on
Major bodies including the American Heart Association classify it among the oils to prefer over butter, lard and palm oil
The erucic acid and 'industrial lubricant' claims that circulate online refer to pre-1970s rapeseed, not to canola

What Olive Detective does with it

It flags canola as a seed oil, and nothing more than that. The flag exists because avoiding seed oils is a preference a large number of people hold, and a scanner that ignored it would be useless to them — not because the app has concluded that canola causes harm. If seed oils are not one of your preferences, the flag does not move your score.

Frequently asked questions

Is canola oil worse than olive oil?: Extra-virgin olive oil is mechanically pressed rather than solvent-extracted and carries polyphenols that refining removes, and it has the stronger long-term evidence base behind it. That is a genuine difference. It does not follow that canola is harmful — the trials comparing canola against saturated fats favour canola.
Is cold-pressed or expeller-pressed canola better?: It avoids the hexane and the high-heat deodorising step, which addresses the processing objection specifically. The fatty-acid profile is unchanged, so it does not address the omega-6 objection at all. Which matters depends on which argument you find convincing.
Is rapeseed oil the same thing?: In the UK and most of Europe, yes — the same low-erucic-acid crop sold under its older name. Olive Detective treats the two as one entry so a British label and an American one resolve to the same flag.
Does canola oil contain trans fat?: Small amounts form during deodorising, typically well under 1% and below the threshold at which a label must declare it. It is far less than a partially hydrogenated oil contains, and partially hydrogenated oils have been removed from the food supply in the US and EU.

Keep reading

Last updated 27 August 2026.

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