Which is healthier: coconut, olive or vegetable oil?

It can be really confusing to know which oil to use when cooking. Is it best to use one type for frying, and another for roasting? Which is healthiest? Here’s a quick overview that may surprise you.

Types of cooking oils

In general, cooking oils are either refined or unrefined. Unrefined oils will have labels including terms like ‘cold-pressed’, ‘virgin’ or ‘extra virgin’, which means they haven’t been processed as much as the refined oils and retain most of the nutrients. Refined oils have often been treated with chemicals to help extend their shelf life and allow them to be used for cooking at higher temperatures. 

When you’re cooking at high temperatures, be aware of the ‘smoke point’, which is when the oil starts to break down into potentially harmful compounds called aldehydes and lose its flavour: when you’re frying or sautéing in a pan, it’s when the oil literally starts to smoke.

However, even the smoke point of extra virgin olive oil is around 160-200°C, and pan-frying on a hob doesn’t tend to go above 120°C. Regular (not extra virgin) olive oil and vegetable oils (rapeseed/ canola, sunflower) are recommended when cooking at higher temperatures, so they are both safe for frying. Extra virgin olive oil would be best cold as part of a salad dressing or mayonnaise for the extra nutrients and flavour.

What about fats?

There are three types of fats you’ll likely have heard about: trans, saturated and unsaturated. This refers to the chemical composition of the fats. What you need to know is that trans and saturated fats are the ones we need to limit our intake of, whereas unsaturated fats can provide health benefits.

• Trans fats are produced when vegetable oils are heated to fry foods at very high temperatures, such as for takeaway meals. They’re also found in some biscuits, pastries and cakes. Trans fats are to be avoided where possible as they have been shown to raise levels of ‘bad’ LDL cholesterol and reduce the ‘good’ HDL cholesterol, as well as increase levels of another form of blood fat called triglycerides. All of these effects can raise your risk of coronary heart disease. Unless you deep-fry a lot or reuse oil and cook at high temperatures, trans fats are not something to worry about when home cooking.
• Saturated fats are also linked to raised levels of non-HDL (or ‘bad’) cholesterol and increased risk of heart disease, which is why they should be limited too. They are found in food such as butter, lard, fatty meats and cheese.
• Unsaturated fats include both mono-and polyunsaturated fats, which have been shown to benefit health when substituted for saturated fats. Unsaturated fats are not associated with raising blood cholesterol, and some may even help lower some cholesterol types. They can be found in plant foods like nuts, seeds, olives and avocados.

So, which oils are healthiest?

You might be surprised to find out that coconut oil is the highest in saturated fats! That means that it is definitely not a ‘health food’ and should be used in low amounts, like butter.

The oils made from mono- and polyunsaturated fats are healthiest, including: sunflower, corn, sesame, olive and rapeseed oils, among others. In the UK, our cheap cooking oil is usually made with rapeseed oil, which is great!

Rapeseed oil (also called canola oil) comes from the black seeds of the rape plant, and when it’s made into cooking oil, it means it has been refined, making it safe to use at high temperatures. Olive oil is also a good option for health, as it is a monounsaturated fat and has the most well-researched health benefits.

Top tips for cooking with oil

1. Use oils in moderation - we need fats in our diet (preferably unsaturated); however, cooking oils are very energy-dense, so a small amount will be quite high in calories. A good tip is to heat the pan, pour what you need and then wipe across the pan with a kitchen paper towel, being careful not to burn yourself, but soaking up extra oil you don’t need. This also prevents the oil from spitting and making a mess.
2. Rapeseed and olive oil are the two I would generally recommend as regular features in your cooking, as they both contain healthy unsaturated fats and are safe to cook at high temperatures.
3. Avoid burning oils, as this causes nutrient degradation and tastes horrible.
4. Consider the flavour and cuisine - if you’re making a curry, coconut oil might be the best choice for flavour. Stir-fry dishes might be best with sesame oil. Roasting some Mediterranean veg? Definitely olive oil.