I remember a time when only a small section in a supermarket was dedicated to cooking oils. Now you need panoramic vision just to view all the different varieties and the market is still growing. I’m not surprised that many get confused when confronted with so many options but I’m hoping that this blog will help you make an informed choice…
So first, let’s consider a few questions…
1. What do you want to use the oil for?
Believe it or not, not all oils can handle the heat. This appears largely dependent on their smoke point. The clue is in the name, as this is the temperature at which an oil starts to smoke, break down and produce ‘off’ flavours and smells. Oils with high smoke points, such as avocado oil, refined/organic sunflower oil, refined coconut oil and refined/organic rapeseed oil are suitable for stir-frying, as well as sautéing, shallow frying and roasting(1-2). Oils with medium smoke points, like cold-pressed rapeseed oil or virgin coconut oil can work for light sautéing and baking, while those with low smoke points, such as pressed and toasted sesame oil, flaxseed oil and hazelnut oil are best saved just for salad dressings and dips(1). As you may have noticed, I’ve not yet mentioned olive oil. There has been lots of conflicting information regarding olive oil in the media over recent years. However research shows that compared with seed oils, good quality extra virgin olive oil is preferable for home frying as it’s less prone to break down (secondary to its high monounsaturated fat content(3) - more on this later) and it also works well in dressings and dips too.
Have I confused you more with the terms like ‘refined, cold-pressed and extra virgin’? If so, let me try and explain a bit more by answering the next question…
2. How much does it cost and is it sustainable?
This often comes down to how an oil is produced. I won’t bore you with the details but ‘cold-pressed’, ‘virgin’, ‘extra virgin’ oils are higher in quality, retaining most of their flavour, colour, antioxidants (which help protect our body’s cells. NB Coconut oil contains virtually no antioxidants) and other beneficial substances during manufacturing. For this reason, they often come with a higher price tag and as already discussed, aren’t always suitable for all types of cooking. Refining oils reduces its flavour, odour, colour and antioxidant level but they are usually cheaper with higher smoke points. Speciality oils, such as flavoured oils and nut oils are made in small quantities, as the process is less efficient(5), with the extra production costs passed onto the consumer. Another important point to consider here is linked with avocado oil. Although it is well known for its ‘heart health’ benefits, its rise in popularity has led to displaced forests, making it unsustainable as well as a costly product(6).
So, this bring us on to the last question…
3. What are the health benefits?
In 2017 it was reported that one in three Brits viewed coconut oil as ‘trendy’ and nearly two in three of those purchasing it, claimed it was ‘healthy’(7). Social media and controversial marketing, lacking in evidence, was likely behind this. Coconut oil is very high in saturated fats (the unhealthy ones) and it has been demonstrated to increase our ‘bad’ cholesterol, with only a moderate increase in ‘good cholesterol’(8). Additional research is still required to see if less-refined versions are more favourable but at present the jury is out and plant-based oils high in unsaturated fats (monounsaturated and polyunsaturated - the healthy ones) remain preferable. There is a wealth of good quality evidence illustrating the health benefits for unsaturated fats, with monounsaturated being in the spotlight for its strong cardioprotective abilities(9-11). Extra virgin olive oil and rapeseed oil are not only high in monounsaturated fats but also plant chemicals (polyphenols), which may provide additional positive outcomes.
Figure 1: The fatty acid composition of a variety of cooking oils.
So to wrap up, if I had to pick one oil, I would choose extra virgin olive oil as it’s definitely the best all-rounder. However, if cost is a big issue, you could try rapeseed oil; most of the ‘vegetable’ oil in UK supermarkets is actually 100% rapeseed oil, so just check the labels. As for the others, they can come in handy if you are looking for a particular flavour but otherwise they're really not necessary.
(2) Native Nurture Vitality (©2019) Introducing native organic refined coconut oil, [Viewed 30th October 2019]. Available from: https://www.nutiva.com/kitchen/introducing-nutiva-organic-refined-coconut-oil/
(3) Antonia Chiou and Nick Kalogeropoulos (2017) Virgin Olive Oil as Frying Oil. Comprehensive reviews in food science and food safety Vol. 16 Available at: https://onlinelibrary.wiley.com/doi/epdf/10.1111/1541-4337.12268
(4) British Nutrition Foundation (2009) Briefing paper - Culinary oils and their health effects. BNF; London, UK. Available at: https://www.nutrition.org.uk/attachments/113_Culinary%20oils%20and%20their%20health%20effects.pdf
(5) British Nutrition Foundation (2009) Oils and fats in the diet. Answers to questions commonly asked about oils. [Viewed 30th October 2019]. Available from: https://www.nutrition.org.uk/attachments/043_Oils%20and%20fats%20in%20the%20diet.pdf
(6) Sheffield Hallam University (2017) Is our passion for avocados killing the environment? [Viewed 30th October 2019]. Available from: https://www.shu.ac.uk/learn-more/avocados
(7) Mintel Press Office (2017) Slippery slope for yellow fats and edible oils [Viewed 30th October 2019]. Available from: https://www.mintel.com/press-centre/food-and-drink/62-of-brits-say-they-are-frying-less-food-at-home-now-compared-to-a-few-years-ago
(8) PEN The Global Resource for Nutrition Practice (2018) Cardiovascular Disease - Dyslipidemia. What effect do tropical oils (palm oil and coconut oil) have on blood lipids. Available from: https://www.pennutrition.com
(9) Scientific Advisory Committee on Nutrition (2019) Saturated fats and health. [Viewed 30th October 2019]. Available from: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/814995/SACN_report_on_saturated_fat_and_health.pdf
(10) National Institute for Health and Care Excellence (2014) Cardiovascular disease: risk assessment and reduction, including lipid modification. Clinical guideline [CG181]. [Viewed 30th October 2019]. Available from: https://www.nice.org.uk/guidance/cg181
(11) The Olive Wellness Institute. Health Benefits of Extra Virgin Olive Oil [Viewed 7th January 2020]. Available from https://olivewellnessinstitute.org/extra-virgin-olive-oil/health-benefits-of-extra-virgin-olive-oil