The Cholestero-Low Blog is Back!
A good few months has passed since I last posted. GP work has been intense and busy, and Cholestero-Low has been through some challenging times! Thankfully, we have overcome those difficult times, and I’m delighted to announce that new, more sustainably packaged Cholestero-Low is available again now online!
And so onto todays blog… Rapeseed Oil!
A conversation was once had, not so long ago, at the Murphy family dinner table concerning the benefits of Olive Oil. My Dad, a pharmacist, whilst in agreement on the benefits of Olive oil, said he would prefer to use Rapeseed oil. This was based solely on the fact that Rapeseed is grown and produced in Ireland.
I went and researched Rapeseed oil, to see what sort of health benefits consuming it may have, and if it has any benefits on your cholesterol levels.
Mum and Dad, this one is for you!
What is Rapeseed oil?
Driving around Ireland, especially around Autumn, you may have wondered about a tall yellow crop growing in the fields.
Well, this is the Rapeseed plant(Brassica napus subsp. napus). Rapeseed is a bright yellow flowering plant from the Cruciferae family.
When the flower grows, seeds are produced and these seeds contain oil. This oil has many uses, from edible cooking oils to animal feed and biofuels.
Because of Rapeseeds ability to grow at relatively low temperatures, it grows very well in Ireland!
There is much more research available about other edible oils such as Olive Oil or sunflower oil. I suspect this is most likely because Rapeseed oil underwent a revolution/ reinvention a few years ago. Previously some versions of Rapeseed oil contained large amounts of Erucic Acid, which can be bad for your heart.
However, and very importantly, this has been regulated by the Food and Drug Administration in the USA and the European Food Safety Authority(EFSA) here in Europe. Rapeseed oil produced for consumption can only have a maximum of 5% Erucic acid. This was achieved by the introduction of cultivars with a naturally low content of Erucic acid.
How is is produced?
The oil is extracted by crushing the seeds of the Rapeseed oil plant at low temperature.
What results, is a deep yellow coloured oil. The quality of the oil is influenced by harvest time, seed storage conditions, pressing intensity, and foreign matter exclusion.
A lot of the Rapeseed Oils produced in Ireland are “cold pressed'”, which means they do not undergo any heat treatment and qualifies them as “Extra Virgin” Rapeseed Oil.
Fats, Fatty Acids, Saturated and Unsaturated
Just a recap on some terms related to fats.
Fats provide energy, and they are essential in our diet for hormone product and certain vitamin synthesis like Vitamin D. The problem is when we consume too much of the wrong fats, as you may have learned in a previous Cholestero-Low blog post. Saturated Fatty Acids should comprise of <10% of our energy intake.
Fatty Acid Lingo
The smaller components of fats are called fatty acids. Most fatty acids can be produced in our body, except for “essential fatty acids” which must be acquired from our diets.
Omega-3 polyunsaturated fats are also known as alpha linoleneic acid(ALA). Dietary sources of Omega-3 would be for e.g Rapeseed, olives or fish especially oily fish.
Omega-6 polyunsaturated fats are also known as linoleic acid (LA). Dietary sources of omega-6 include safflower oil, sunflower oil, sunflower seeds and pumpkin seeds.
Omega-9 monounsaturated fats, are also known as oleic acid.
Omega-3 and Omega-6 have been extensively studied and are widely accepted to be beneficial for our heart and health, in particular omega-3.
Other rich sources of ALA/omega-3 include flax, chia seeds, ligonberry, walnuts and rapeseed oil. The richest sources of omega-3 long-chain PUFA are oily fish, fish oil and cod liver oil. Organic milk and meat contain 50% more omega 3.
You might come across debate about omega-3 and omega-6 ratios. The guidance from heart foundations and the WHO would be to replace saturated fat with some unsaturated fat, including both omega-3 and omega-6 fatty acids to help reduce the risk of heart disease.
What are the differences between Rapeseed Oil and Olive Oil?
Apart from coming from different plants(rapeseed)/(olives), it is their nutritional value that separates them. There is also the issue of ‘heating point” , which we will come to later.
Now, let us look into Rapeseed Oil in more detail.
1. Lower in Saturated Fats.
In terms of its health properties, this could be considered Rapeseed Oils greatest assets.
Of all the oils, it contains the lowest amount of saturated fats, at approximately 7%.
It is important to aware of the amount of saturated fats we consume. Diets heavy in saturated fats such as processed meats, processed foods(e.g pastries, chips) increase cholesterol and can result in cardiovascular disease. As always with regards to fats, we want to eat more healthy unsaturated fats(e.g fish, avocados), and less saturated fats.
2. Higher Polyunsaturated Fatty Acids
Rapeseed oil provides both omega-3 and omega6. The high quantity of omega-3 in Rapeseed oil, allows it to carry the EFSA claim that foods ‘high in omega 3 and ALA contributes to the maintenance of normal blood cholesterol levels’.
The predominant fat in Rapeseed oil is monounsaturated fatty acids. Omega-9 makes up 61% of Rapeseed oil. Omega-9 has been shown in studies to have a positive effect on cholesterol. Its benefits have been studied by scientists looking at the Mediterranean Diet, where Olive oil is the main oil used. However, olive oil and Rapeseed oil contain approximately the same amount of omega-9.
Fat Content of Rapeseed Oils Vs Olive Oils
- Canola Oil = Rapeseed Oil
- SFA= Saturated Fatty Acids
- MUFA = Monounsaturated Fatty Acids
- PUFA= Polyunsaturated Fatty Acids
Cholestero-Low does not own these tables.
Taken from “Trends in Food Science and Technology”
3. Heating point/ Stability High Boiling point.
Most oils and fats are healthiest when not heated. A lot of the benefits of vegetable oils, like Rapeseed and Olive Oil, are attributed to their antioxidant properties. These antioxidant properties prevent the breakdown of fats to harmful compounds, and can have an anti-inflammatory effect. However heating the oils can negate some of the positive effects of the oils.
Once oils start to smoke, their fatty acid etc start to degrade.
However, some evidence shows that Rapeseed oil has a higher ‘smoke point’, i.e a high temperature at which they start to smoke. This could mean that more of antioxidants are not destroyed when used in cooking. There is also evidence shows that heating Rapeseed oil is more stable than olive oil, meaning less breakdown and more health benefits.
However, degradation of oil’s properties is dependent on a number of factors like the amount used, how long it is heated for and whether the oil is reheated.
Furthermore, there are no large randomised trials or peer reviewed articles comparing these smoke points.
What is definitely true is that both oils, Olive oil and Rapeseed oil are healthier when consumed without heating, (e.g on your salad or on your bread).
Speaking of cooking here are some Heart Healthy Recipes!
Side note: Improving heart heath on a budget!
- Higher in omega-3 polyunsaturated fats. √
- Lower in saturated fats. √
- Shown to lower cholesterol and bad cholesterol (LDL) because of the omega-3. √
- Made in Ireland √