Is rapeseed (canola) oil healthy? What research shows

Ask what fat the Nordic diet cooks with and the answer is almost always rapeseed oil — what North America calls canola. It runs through the dressings, the roasting pans, and the baking, and it's one of the few parts of the diet with its own stack of controlled trials. Those trials agree on one point and are mixed on another.

What canola is, and why the Nordic diet uses it

Canola is rapeseed bred for low erucic acid: the same plant, made into a food-grade oil. It's inexpensive, grown across Scandinavia, and high in unsaturated fat, which is the trait the cholesterol research turns on.

Rapeseed oil versus butter and dairy fat

The clearest signal comes from comparing it with saturated fat. In a Swedish crossover trial, adults with high blood lipids who ate a rapeseed-oil diet for three weeks lowered their total and LDL cholesterol by about 17% and their triglycerides by 20%, while the same people on a dairy-fat diet did not. A network meta-analysis of 54 trials placed rapeseed among the oils that lower LDL more than butter. Swapping saturated fat for unsaturated fat to lower LDL is textbook nutrition; these trials show rapeseed oil doing exactly that.

The rapeseed oil research collects the trials with their numbers.

Where it changes nothing

The effect has limits. A 2019 meta-analysis of 27 trials found canola oil lowered LDL and total cholesterol modestly — about 6 to 7 mg/dL — but did not move HDL, triglycerides, or the apolipoproteins. One Swedish trial also found a rapeseed-oil diet nudged lipoprotein(a) up 6% and left HDL flat. The cholesterol shift is real and modest, not a cure-all.

Is it safe to cook with?

A common worry is that heating a polyunsaturated oil creates harmful oxidation products. A Swedish study tested that directly and found a rapeseed-oil diet did not raise markers of lipid oxidation compared with a saturated-fat diet. That is reassurance on one specific concern, measured with surrogate markers rather than long-term health outcomes.

Working it into a Nordic plate

Rapeseed oil is the default fat for the everyday cooking this diet is built on — whisked into a mustard dressing, tossed with roots before roasting, or brushed on fish. If you're tracking it, say the dish to Nordic Diet Companion ("red cabbage salad with rapeseed oil") and it logs the fat along with the rest of the meal, no measuring. For a place to start, the Nordic red cabbage and apple salad uses it in the dressing.

FAQ

Is canola oil the same as rapeseed oil? Yes. Canola is a rapeseed variety bred for low erucic acid, and the studies use the terms interchangeably. It's the main cooking fat of the traditional Nordic diet.

Does rapeseed oil lower cholesterol? Modestly. A meta-analysis of 27 trials found canola oil cut LDL about 6.4 mg/dL and total cholesterol about 7.2 mg/dL, with no change in HDL or triglycerides (Ghobadi, 2019). This is education, not medical advice.

Is rapeseed oil better than olive oil? The trials don't settle it. In a head-to-head study, canola oil lowered triglycerides and lipid ratios while olive oil showed no significant lipid change, but that was a small, specific group (Yahay, 2021). Both are unsaturated oils.

Is it bad to heat rapeseed oil? One Swedish trial found a rapeseed-oil diet did not increase lipid-oxidation markers versus saturated fat (Södergren, 2001). The oxidation worry wasn't borne out on those markers, though it wasn't a long-term outcome study.

Where can I read the studies? The rapeseed oil research index lists each trial with its numbers and limits, and what defines the Nordic diet sets the wider context.