Rapeseed oil is one of the most widely available and commonly used oils, but is it really good for us or could adding it to our diets cause more harm than good?
What is rapeseed oil?
Rapeseed oil is the oil derived from the seeds of the rape or rapeseed plant. This is the gloriously vivid yellow flowering plant which is abundant in the British countryside throughout summer.
The rapeseed plant belongs to the cabbage family and is closely related to mustard and turnip, so rapeseed oil is considered to be a vegetable oil. In fact, many oils marketed as simply 'vegetable oil' will comprise of mainly rapeseed oil.
Rapeseed Oil vs. Canola Oil
There are 2 types of rapeseed oil: industrial and culinary.
Industrial rapeseed oil is used in the automotive and chemical industries, it is not safe for human consumption due to its high content of something called 'erucic acid.' This is an acid occurs at high concentrations in oils derived from the cabbage family, such as rapeseed and mustard oil.
Culinary rapeseed oil is better known as Canola oil. It is a genetically modified version of rapeseed oil which has been bred to contain lower levels of erucic acid, making it safe for consumption (well so we are told conventionally). You can learn more about rapeseed oil and other unhealthy 'vegetable' oils in our Pillar Article below:
👉 The Unsaturated Truth: Drop Seed Oils If You Want To Be Healthy.
History of rapeseed oil
Why was rapeseed oil genetically modified then? Rapeseed was found to be one of the most disease- and drought- resistant oil crops, but there was one problem - the naturally high erucic acid content was harmful to both animals and humans. Studies found it to be toxic and connected it to a whole variety of negative health outcomes.
Rapeseed Oil is Genetically Modified
So, in the 1970s rapeseed was genetically modified to produce another version of the plant which contained much lower levels of erucic acid. The resultant oil from this plant was originally named Low Erucic Acid Rapeseed (LEAR), but understandably the shelf appeal of this was poor! Therefore, it was later renamed Canola oil (a combination of 'Canada' and 'oil') and the plant became known as the Canola plant.
Happy days right - same great yielding plant with lower levels of erucic acid? Not exactly. Food grade rapeseed oil (or Canola oil or LEAR - whichever you want to call it!) came with its own drawbacks and consequences.
How is rapeseed oil produced?
Aside from being genetically modified, the way in which rapeseed oil is produced is actually one of the main things which makes it bad for us.
Rapeseed Oil is Heavily Processed
Like many seed oils, rapeseed oil is often heavily refined, bleached and deodorised to 'clean' the oil. This is necessary to remove any free fatty acids and unappealing colours from the oil, usually facilitated by a harmful chemical named hexane.
This process alters the nutritional content of rapeseed oil, reducing levels of vitamins & antioxidants as well as altering the Omega-3 to Omega-6 ratio.
Once 'cleaned', rapeseed is partially hydrogenated to increase its stability once processed. This hydrogenation process has been shown to convert some of the unsaturated fats to trans fatty acids, which in our opinion and many others are harmful to human health - and so the purported health benefits begin to unravel!
Rapeseed oil nutrition
Rapeseed oil is low in saturated fat and high in monounsaturated fats such as Oleic acid. It is also touted as a good source of Omega-3 and Vitamins E & K, which are fat soluble and so easier to absorb in a high fat vessel such as oil.
But as mentioned, heavily processing the oil takes the end product worlds away from its natural nutritional profile. Refined rapeseed oil is lower in vitamins, lower in antioxidants and higher in saturated fats and trans fats acids compared with its cold-pressed counterpart.
Omega 3 : 6 Ratio of Rapeseed Oil
Before processing, rapeseed has an Omega-3-6 ratio of around 2:1, but the high temperatures used to process the oil convert many of the Omega-3 fatty acids to trans fats.
This elevates the ratio of Omega-6 to Omega-3, which has pro-inflammatory effects and has been shown to create inflammation in the body. As with most seed oils, this is bad news and just one thing which makes veg and seed oils so bad for us. You can learn more about this in our article below:
👉 What's the deal with veg oils? Why you need to avoid them
What about cold-pressed rapeseed oil?
So far, we've been writing about industrialised rapeseed oil, the kind you find in large clear plastic containers recommended for cooking. Cold-pressed rapeseed will come in much smaller, dark glass bottles. It has an artisanal feeling to it and is correspondingly more expensive than its refined version. Cold-pressing was already thousands of years old when Socrates was philosophising around Ancient Greece. This simple process was done by hand with a pestle and mortar or on scale with a donkey-powered version. Today, the process is basically the same, but the heavy stones are replaced with a hydraulic press or screw, which slowly crushes the rape seeds to keep the temperature down as the oil is extracted. Without a doubt, cold-pressed rapeseed oil is a much better product than the refined rapeseed or canola versions. It naturally contains vitamin E, a fat-soluble anti-oxidant vitamin, as well as the omega-3 ALA. But, when stored at room temperature, these benefits begin degrading, and the overall quality of the oil drops significantly. (1) Also, the issue with erucic acid persists whether it's cold-pressed or refined. Further, cold-pressed rapeseed oil is about 18-22% linoleic acid (omega-6)—we have a pillar article which focuses on the issues with this oil—which is easily damaged under normal storage conditions and is arguably being eaten to excess. So, whilst cold-pressed rapeseed oil is a much better product than the refined version, our philosophy is, why bother when there are some other great oils without the same issues: olive oil, coconut oil, and avocado oil plus healthy animal fats?
Is rapeseed oil healthy?
Rapeseed oil is promoted by health authorities and seen by most people as a healthy oil. Naturally, it is a good source of Omega-3, low in saturated fat and provides a rich source of heart healthy Oleic acid. Tides are turning however on saturated fats being bad, with animal fats and Coconut oils making a resurgence in popularity linked to their health benefits.
The genetically modified Canola oil was seen as a cost-effective and healthier alternative to oils higher in saturated fat, which of course were demonised during the 1980s.
However, being a monounsaturated fat with high levels of oleic acid distracts from a vast history of genetic modification and harmful production methods, which are far more harmful to health than any kind of saturated fat!
Whilst you can get cold-pressed rapeseed oil which is the lesser of two evils compared with it's heavily processed counterpart, rapeseed oil remains genetically modified and GMO crops have been linked to a multitude of negative health outcomes.
The fact that the vast majority of rapeseed oil is actually refined and heavily processed - making it pro-inflammatory and full of chemicals too - seals the deal for us; when it comes to the question is rapeseed oil healthy? The answer is no!
References
- Evidence of the health benefits of Canola oil - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3746113/
- Erucic acid in feed and food - https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2016.4593
- Trans fatty acid content of products made with Canola oil - https://www.ars.usda.gov/ARSUserFiles/80400525/Articles/JADA106_867-880.pdf
- The importance of Omega-3 / Omega-6 fatty acid ratio for human health - https://pubmed.ncbi.nlm.nih.gov/18408140/
- Genetically modified plants and human health - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2408621/
All information provided on our website and within our articles is simply information, opinion, anecdotal thoughts and experiences to provide you with the tools to thrive.
It is not intended to treat or diagnose symptoms and is definitely not intended to be misconstrued for medical advice. We always advise you seek the advice of a trained professional when implementing any changes to your lifestyle and dietary habits.
We do however recommend seeking the services of a trained professional who questions the conventional wisdom to enable you to become the best version of yourself.
References
1: Wroniak, Małgorzata, and Agnieszka Rękas. “Nutritional value of cold-pressed rapeseed oil during long term storage as influenced by the type of packaging material, exposure to light & oxygen and storage temperature.” Journal of food science and technology vol. 53,2 (2016): 1338-47. doi:10.1007/s13197-015-2082-y
