Once upon a time, your mum had one type of cooking oil, and quite probably your nanna only had a tub of lard lurking in the back of the fridge somewhere.
These days various oils occupy a great deal of supermarket real estate and it would be the rare cook who didn’t have more than two varieties at the very least.
We can’t imagine cooking without oil, but the truth is it’s liquid fat, and some are better for you than others.
But what makes a ‘good’ oil? Three things: fatty acid content, the refinement process and its smoke point.
Fatty acids
All cooking oils have varying amounts of monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA) and saturated fatty acids (SFA).
We could go into the scientific explanation of what’s best for you, but it’s convoluted and confusing.
Health website MGBFood probably sums it up best: MUFAs are the best; PUFA-rich oils are okay but they are unstable and when they degrade they can develop lipid oxidation by-products, which can cause inflammation, hypertension and atherosclerosis; SFAs are stable, but are the most likely to elevate cholesterol.
Refining
Generally, the less refined the oil is, the better it is for you.
Simple extraction methods such as cold pressing use pressure to release the oil, which is then filtered to remove solids.
More extreme methods will use chemicals, heat and high pressure to draw out the oils, which can significantly damage the oil’s nutritional value.
Smoke point
Smoke point is the point at which a fat or oil begins to smoke, or produce that blueish haze you see in an overheated pan.
Heating beyond the smoke point can promote the formation of pro-inflammatory free radicals and a carcinogenic compound known as acrolien, as well as irritate your eyes, nose and throat. And apart from anything else, any food cooked in that is probably going to taste bad.
Free radicals are unstable atoms that can damage cells and cause illness and accelerate ageing.
So an oil with a high smoke point – such as olive oil – is able to take more heat, and thus be more stable and healthy.
Which is not to say low smoke point oils don’t have a place in cooking. If you just want to quickly cook something such as a stir fry or a fillet of fish, a heavy, high smoke point oil such as olive oil may be too heavy.
So here’s a ranking of the best oils for your health.
1. Extra virgin olive oil
Extra virgin olive oil has a high smoke point (176°C), is rich in vitamin E, its primary fatty acid is MUFA oleic acid and has a low level of processing.
Studies show it protects against heart disease, is anti-inflammatory and improves gut health.
If you find the taste too much, there are light-flavoured varieties available.
Olive oil will go rancid, and it’s best to use it within six months of opening the container, although some even recommend three months.
2. Avocado oil
A neutral-flavoured oil, with many similar nutritional benefits to olive oil.
It also takes about six months to become rancid and its nutritional benefit varies depending on the extraction process and where the avocados were grown.
3. Almond oil
Naturally it’s a nutty-flavoured oil, heavy with MUFAs that can even be used topically to moisturise skin.
It’s hard to come by in its unrefined form, but the commercial offerings still provide plenty of nutritional benefits.
4. Sesame oil
We’re once again talking about the unrefined version here, not the one you drizzle over Asian dishes, which is also hard to find.
This oil has about the same amount of MUFAs and PUFAs, which lowers the smoke point and makes it suitable for low-heat cooking applications, salad dressings or tossing through noodles.
Do you use different oils for different cooking purposes? Why not share your tips in the comments section below?