Cooking oils – the good & bad

All cooking oils are not created equal!

We can largely break our cooking oils down into two categories: saturated vs unsaturated fats. The unsaturated fats can be further broken down into poly- and monounsaturated fats. 

All oils have a smoke point temperature, above which the oil is no longer stable. You shouldn’t cook with oils at a higher temperature than their smoke point.  

Cooking oil can be a great source of heart-healthy fats AND can increase absorption of our fat-soluble micronutrients. When oil is cooked beyond its smoke point temperature, however, it begins to oxidize and release free radicals which may impact your health negatively. 

Let’s look at some of the best cooking oil options:


Olive oil is full of monounsaturated fats and Vitamin E= great for the heart and may have anti-cancer and anti-inflammatory properties. With a smoke point of approx. ~176 degrees Celsius, it is great for roasting, baking and pan-frying. Ideally, look for extra virgin olive oil.


A bit exxier, but with a super high smoke point of 271 degrees Celsius, it is great for your higher-temperature cooking. Like olive oil, it is also a great source of monounsaturated fatty acids and Vitamin E. Some evidence shows that components of avocado oil may help lower blood pressure, bad cholesterol, and triglycerides.

It may also help reduce joint inflammation, enhance the absorption of other nutrients, and protect cells against free radical damage.


Another more expensive choice but also a higher smoke point than olive oil (210C). With a stronger taste, this oil is not as versatile as avocado oil or olive oil but is tasty for stir-frying and use in salad dressings. It is unique in that it contains sesamol and sesaminol, two antioxidants which may protect against certain diseases.

Oils to avoid for cooking:

Fish oil – while high in heart healthy omega-3 fatty acids, it is possible to get too much of a good thing and these FA are not stable when heated.

Flax oil – a great source of some heart healthy fats but has a very low smoke point so best enjoyed as a salad dressing.

Palm oil – while also a heart healthy mono unsaturated fat, it has huge environmental implications related to the rainforest destruction to source it, so steer clear of this one.

Walnut oil – like flax oil, a great source of our anti-inflammatory fats but with its low smoke point best for cold uses such as salad dressings.

‘Vegetable/sunflower/canola/rice bran oil’- the use of these oils has increased over the years since saturated fats such as butter where found to contribute to heart disease. The high intake of these vegetable/seed oils may be problematic in itself though. These oils are all high in a particular kind of fatty acids called omega 6. While omega-6 in itself isn’t bad, we ideally need a dietary intake with a balance of omega-3 FA and omega-6 FA. But partially due to the use of these oils, the ratio has shifted to be much more in favour of these omega-6 FA. There is some evidence that this high intake of omega-6 may increase the risk of obesity, heart disease, arthritis and IBD. This is not 100% confirmed by the science but there does seem to be a correlation.

To keep things simple, wherever possible choose olive oil for cooking and dressings salad and aim to minimise consumption of the processed seed and vegetable oils.


About the author

Cheyenne Holman

Cheyenne Holman

Accredited Practicing Dietitian (APD)
Accredited Sports Dietitian
Certified Personal Trainer
Yoga Alliance Certified Yoga Teacher