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Cleaning up the world, one person at a time
The good, the bad and the ugly.
By Fi Dann Ray, MSc Applied Toxicology, MSc Chiropractic
July ‘18
Rapeseed oil is one of the world’s most important oil seed crops, after palm and soybean oils. Rapeseed oil used to contain over 40% Erucic acid, which was shown to be damaging in animal studies, so the high-erucic rapeseed oil could only be used for non-food uses.
Canadian scientists developed a low erucic acid oil through traditional plant breeding methods and named it ‘Canola’ oil. This was known as low-erucic oil in Europe (LEAR). These are now known as rapeseed oil in europe. In the late 1990’s a GM version of rapeseed was introduced. 90% of the world’s rapeseed oil crop is now from GMO seeds.
The good
Lets start with the positives. Rape seed oil has a high smoke point so is stable to cook with.
Rape seed oil also has a good proportion of omega 3 essential fatty acids – the anti-inflammatory fats that our bodies cannot make in sufficient quantities.
It has low levels of saturated fats and high levels of mono and polyunsaturated fatty acids. These together with plant sterols and tocopherols are regarded as having cardioprotective properties. The FDA regarded canola oil as reducing the risk of coronary heart disease due to the unsaturated fat content[1].
The bad
Most of the cardioprotective benefits of rapeseed oil is from the alpha-linoleic acid – which oxidises really easily in frying, rendering it useless[2].Extra virgin olive oil is still considered to be the better choice.
Magnesium deficient mice fed a diet high in omega-3 EFA (rapeseed oil) experienced greater neuroprotection than those fed a sunflower and corn oil high omega 6 diet or a diet rich in mono-unsaturated fatty acids[3]. As good as that is, again it was the ALA part of the oil – which gets damaged and changed during cooking.
So Rapeseed oil cooked is a very different substance health-wise to the uncooked.
A true-ism for any vegetable or seed oil is that the extraction method to get the oil from its source makes a huge difference to the health profile and properties of that oil. Most commercial or mass market oils are extracted using solvents such as hexane (removed from the product prior to sale) and at high temperature and pressure. This affects the poly- and mono-unsaturated fatty acids and causes some rancidity. This smell is then removed via a deodorisation procedure. There is also an increase in the trans-fatty acid levels of the oil too.
By contrast cold processed extra virgin, non-GMO and preferably organic oils have very different health effects. They are best used uncooked – as mayonnaise, salad dressing, drizzled on foods, or cooked for the minimum time possible. The smoke point for olive oil is higher than the ideal frying temperature of 180 degrees c.
To see how the average rape seed oil you see on the supermarket shelves is made, watch this.
Now, for the contrast, how cold pressed rape seed oil is made.
The ugly
In mouse models of Alzheimer’s disease, mice fed canola oil over a long period had increased body weight, poorer working memory, lower markers of synaptic integrity and increased nerve cell pathology[4].
Hypertensive rats fed canola oil vs Perilla oil or shortening, had shorter survival times and larger haemorrhagic strokes that the other two groups, and shorter survival time than the control group. Canola oil fed rats also had higher blood lipids and reduced platelet counts[5]. Higher levels of kidney injury were also seen in these rats when fed canola/ rapeseed oil[6].
So if you are going to use rapeseed, at least use it at low temperatures or added to food after cooking. Consider using other oils such as Olive oil (cold pressed better), butter or coconut oil.
Health tip
Make your own mayonnaise! It really is ridiculously easy, and earns you plaudits from friends and family as everyone thinks it is tough to do. It will give a good dose of olive oil and is so much better for you than shop brought mayonnaise. It is a more creamy yellow colour than conventional mayonnaise due to the deeper colour of the olive oil. If you want more omega 3 oils in the recipe you can add some flax oil – has to be cold processed extra virgin grade – to the olive oil, however the taste is rather strong if used in higher proportions so I suggest ¼ to 1/5 flax oil of the total oil quantity if you use it. Other oils can be added if wished. Coconut oil doesn’t really work due to its solid state at cooler temperatures and pumpkin seed oil turns mayo green (just so you know).
Fi’s easy mayonnaise recipe
1 large egg
4tsp lemon juice
Mustard – to personal taste. I use 1 tsp wholegrain mustard
¼-1/2 tsp salt – again to personal taste
14-1/2 tsp white or black pepper
optional extras – 1tsp herb provencal or 1 tbsp fresh herbs, several crushed cloves of garlic.
250-300 ml approx. Extra virgin olive oil
Put all the ingredients except the olive oil into your mixing container/ jar and blend using a stick blender. Keep blending on a medium to slow speed and drizzle in the olive oil slowly until the mixture thickens and it is taking longer for the oil to blend it. Once thick enough (it will thicken further when chilled) then it is done and ready for you to enjoy. Refrigerate it and it will be good for 5-7 days.
All amounts are fairly approximate!
References.
[1] Lin, L., Allemekinders, H., Dansby, A., Campbell, L., Durance-Tod, S., Berger, A., & Jones, P. J. (2013). Evidence of health benefits of canola oil. Nutrition Reviews, 71(6), 370–385. http://doi.org/10.1111/nure.12033
[2] Hoffman, R., & Gerber, M. (2014). Can rapeseed oil replace olive oil as part of a Mediterranean-style diet? British Journal of Nutrition, 112(11), 1882-1895. doi:10.1017/S0007114514002888
[3] Pages, N., Maurois, P., Delplanque, B., Bac, P., Martin, J.-C., Du, Q., … Vamecq, J. (2011). Brain protection by rapeseed oil in magnesium-deficient mice. Prostaglandins, Leukotrienes, and Essential Fatty Acids, 85(2), 53–60. http://doi.org/10.1016/j.plefa.2011.05.001
[4] Lauretti, E., & Praticò, D. (2017). Effect of canola oil consumption on memory, synapse and neuropathology in the triple transgenic mouse model of Alzheimer’s disease. Scientific Reports, 7, 17134. http://doi.org/10.1038/s41598-017-17373-3
[5] Jingmei Cai, Ja-Young Jang, Jihyun Kim, Kyungha Shin, Kwang Sei Kim, Dongsun Park, Tae-Su Kim, Sung-Pyo Lee, Byeongwoo Ahn, Ehn-Kyoung Choi, Junsoo Lee & Yun-Bae Kim (2016) Comparative effects of plant oils on the cerebral hemorrhage in stroke-prone spontaneously hypertensive rats, Nutritional Neuroscience, 19:7, 318-326, DOI: 10.1179/1476830514Y.0000000132
[6] Takoto Miyazaki, Naoya Takemura, Shiro Watanabe, Noriaki Hata, Yoshihisa Misawa, Harumi Okuyama,. Dietary docosahexaenoic acid ameliorates, but rapeseed oil and safflower oil accelerate renal injury in stroke-prone spontaneously hypertensive rats as compared with soybean oil, which is associated with expression for renal transforming growth factor-β, fibronectin and renin,. Biochimica et Biophysica Acta (BBA) – Molecular and Cell Biology of Lipids, Volume 1483, Issue 1, 2000,Pages 101-110, ISSN 1388-1981, https://doi.org/10.1016/S1388-1981(99)00180-8.
Detoxicology 