nutrition

Canola oil dangers: What you need to know

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Rapeseed oil is a common ingredient in our kitchens, but it often divides opinion: some consider it an ally due to its richness in omega-3s, while others avoid it because of its heat sensitivity or the presence of erucic acid in older varieties. With so much conflicting information, it's hard to know how to use it correctly.

Whether you're an athlete, a cooking enthusiast, or simply health-conscious, understanding the real dangers and best practices surrounding rapeseed oilis essential to reap all its benefits without risk.

Why is rapeseed oil so controversial?

Rapeseed oil has long been considered one of the best everyday oils, particularly for its excellent omega-3 content. But it also has a reputation as a fragile oil that should not be cooked, or even as harmful if heated. So, what's the real story?

An oil rich in nutrients but sensitive to heat

Rapeseed oil has a particularly interesting nutritional profile (1). It combines:

  • omega-3 (alpha-linolenic acid) in high proportion
  • omega-6 in moderate quantities
  • omega-9 like many vegetable oils
  • polyphenols and other bioactive compounds

But this richness comes with a reality: omega-3s are sensitive to heat, oxidation and light. In other words, it's not the oil itself that's dangerous, but the act of overheating it or storing it in poor conditions.

Erucic acid and rapeseed oil

Erucic acid is a monounsaturated fatty acid naturally present in certain oilseeds, notably rapeseed, mustard and radish. In its older forms, rapeseed contained high amounts of this fatty acid, which raised concerns due to potential health effects when consumed in high doses over long periods.

Today, modern rapeseed oils intended for food are derived from "double zero" varieties, which are much lower in erucic acid. In accordance with European standards, these oils contain less than 2% erucic acid, making them safe for normal consumption.

Rapeseed oil: real danger or simply misuse?

Is there a danger in consuming raw rapeseed oil?

When consumed raw, rapeseed oil is considered safe, and scientific data even show beneficial effects on the body due to its nutrient content.

What can be problematic is not the consumption itself, but:

  • an oil that is poorly stored (exposed to light, stored for a long time)
  • an oxidized oil
  • an oil heated to too high a temperature

As long as it is used under appropriate conditions, rapeseed oil is not dangerous.

The real risk: oxidation during cooking

Rapeseed oil has a relatively low smoke point (variable depending on whether it is virgin or refined). This means that it begins to degrade faster than other oils when heated to high temperatures.

When an oil exceeds its smoke point:

  • it produces more oxidation compounds
  • its fatty acids deteriorate
  • it loses its nutritional qualities
  • it can release potentially irritating compounds

These phenomena are not specific to rapeseed oil: all vegetable oils undergo changes when they are overheated. But with rapeseed oil, the problem arises more because its omega-3s are very sensitive.

Should you avoid cooking with rapeseed oil?

The use of this oil must be adapted:

  • for frying or very hot cooking: no
  • for gentle cooking (≤150°C): possible but not the most suitable
  • for seasoning: ideal

It is therefore not a question of toxic danger, but of culinary inadequacy.
For high-heat cooking, other oils are better suited: olive, peanut, coconut, refined rapeseed.

Virgin vs. refined rapeseed oil: what are the differences?

The distinction between virgin and refined oil is important for understanding the controversies surrounding its cooking.

Virgin rapeseed oil: the best nutritional quality

It is obtained by cold pressing, which preserves:

  • omega-3s
  • polyphenols
  • fat-soluble vitamins

It is ideal for:

  • salad dressings
  • cold dishes
  • gentle cooking
  • the nutritional needs of athletes

However, like any oil rich in omega-3s, it is fragile.

Refined rapeseed oil: more stable, but less nutritious

It undergoes treatments designed to:

  • remove impurities
  • increase the smoke point
  • stabilize the oil for cooking

But these processes reduce some of the micronutrients. For cooking, it is nevertheless the most suitable version.

How to choose quality rapeseed oil?

Here are the essential criteria to avoid any real problems.

1. Choose virgin oil for cold use

Look for the mentions:

  • "virgin"
  • "cold-extracted"
  • "cold-pressed"

2. Use refined oil for medium-heat cooking

It will withstand cooking better than virgin oil.

3. Store the bottle in a cool place, away from light

The kitchen can be too hot. A cool cupboard is ideal.

Mistakes to absolutely avoid

To preserve the nutritional quality and stability of rapeseed oil, certain practices should be avoided.

  • Heating virgin rapeseed oil over high heat
  • Leaving it open for several months
  • Storing it near the oven
  • Exposing it to sunlight on the countertop

Rapeseed oil danger: in summary

Rapeseed oil is perfectly safe when consumed raw and is an excellent source of omega-3s, beneficial for the body. However, it is best to avoid heating it to high temperatures, as its omega-3s are very sensitive to heat and the oil risks oxidizing, thus losing its nutritional qualities.

It is also important to distinguish between virgin oil and refined oil: virgin oil, ideal for dressings and gentle cooking, retains its nutrients but remains fragile, while refined oil is more stable for cooking, but less nutritionally rich. To fully benefit from its advantages and limit risks, store your oil away from light and heat, and avoid heating it over high heat.

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