Choosing fats and cooking oils

Published: 21 April 2026

How do you choose the best fats and oils to cook with? From olive oil to canola oil, we explain everything you need to know about the best fats and oils for your heart.

Fats and oils are a key part of a healthy diet. Some come from whole foods that we eat, such as dairy products, nuts, seeds and avocados. They are also added to food we cook and prepare. 

In food preparation, fats and oils are used in many ways, including: 

• sautéing  
• frying 
• barbecuing 
• roasting  
• as an ingredient, e.g. in salad dressings, baking etc.  

With a huge range of oils now on the market, you may wonder which is the best oil for cooking and food preparation.  

In reality, there is no single best oil. The oil you choose depends on the temperature you’ll be cooking at and the flavour and aroma required. 

The key is to choose the right oil for the job.  

What are the healthiest fats and oils?

Some fats and oils are better for your heart health than others. This is because they each have different amounts of:  

• fats that are heart-healthy (monounsaturated fats and polyunsaturated fats) 
• fats that increase your risk of heart disease (saturated fats). 

The best options for heart health are fats and oils that are:  

• higher in polyunsaturated or monounsaturated fats  
• lower in saturated fats.  

Swapping saturated fats for heart-healthy fats (mono- or polyunsaturated) is a simple change that will reduce your risk of heart disease (heart attacks or stroke). 

Replacements for butter, beef fat and ghee

Butter, beef fat and ghee (butter with the water and milk solids removed) have high levels of saturated fat. They are not the best choices for our hearts.  

It is best to replace these fats with plant-based oils that contain heart-healthy polyunsaturated and monounsaturated fats.  

Studies show that a higher olive oil intake and replacing butter with olive oil are both associated with a reduced risk of heart disease⁽¹⁾. 

Research also shows swapping butter and beef fat with plant-based oils helps reduce harmful cholesterol⁽²⁾, which is a key risk factor for heart disease. Commonly-used oils that show the biggest benefits are canola (rapeseed) oil and sunflower oil.

What about palm oil and coconut oil?

Palm oil and coconut oil are not heart-healthy, even though they are plant oils. Both are high in saturated fat which increases ‘bad’ cholesterol and your risk of heart disease.  

In recent years, coconut oil has become more popular. Although using small amounts to add flavour is ok, it's better to choose another oil, like olive oil, as a main cooking oil. 

Cold-pressed oils vs refined oils

The way in which an oil is produced will impact its nutritional value, taste and smell. 

Cold-pressed oils 

Cold-pressing is when the oil is extracted without any heat and without any use of chemicals. It is used to produce extra virgin oils.  

Varieties that are readily available in New Zealand include: 

• extra virgin olive oil 
• extra virgin canola oil 
• extra virgin high oleic sunflower oil 
• extra virgin avocado oil. 

This processing technique results in a less-processed oil which is higher in nutrients and antioxidants with most of the flavour and colour retained.  

These oils are nutritionally better, but they are also more expensive because they are more costly to produce.  

Refined oils  

Refined oils are the most processed kind of oils. They are ‘hot-pressed’, which is when the oil is extracted using heat and pressure.  

This extraction process uses refining, bleaching, deodorising and chemicals⁽³⁾. These steps remove some of the antioxidants and nutritional value. It also reduces the flavour, odour and colour of the original oil.  

These oils are usually cheaper and are often more stable at higher temperatures.  

What are the best oils to cook with?

Higher temperature cooking 

Avoid overheating oil when cooking. When an oil is overheated it produces unwanted compounds, which can be harmful to your health.  

When an oil starts burning and smoking (its ‘smoke point’), it is a sign that damage to the oil has started. 

Affordable options for high-temperature cooking such as shallow frying and barbecuing include: 

• canola oil 
• high oleic sunflower oil 
• rice bran oil 
• refined light olive oil. 

Extra virgin olive and avocado oils (particularly New Zealand and Australian varieties) can also be used for high temperature cooking. However, due to their higher cost they may be best used for drizzling over pasta or a salad, where you can get the most out of their flavour and aroma.  

Lower temperature cooking and food preparation 

You can be a lot more flexible with the type of oil you use for lower temperatures or cold uses, like salad dressings and sauces, because the oil isn't being heated.  

Choose an oil that you can afford and like the taste of, for these dishes. 

Good choices if you want more flavour include:  

• extra virgin olive oil 
• flaxseed oil 
• sesame oil  
• walnut oil 
• avocado oil.  

If you’re looking for a more cost-effective option consider: 

• canola oil 
• high oleic sunflower oil 
• rice bran oil 
• refined light olive oil. 

Deep frying and heart health

Reusing the same oil for high temperature cooking (e.g. deep frying) can produce compounds that can be potentially harmful to our health.  

Our recommendation is to avoid deep-fried food altogether. Such foods are often high in saturated fat and salt which increase our risk of heart disease. Consider using an air fryer or baking food in the oven instead. 

If you do need an oil for deep frying at home then more stable and better oils include canola, high oleic sunflower oil, rice bran oil and light olive oil.

How to look after your oils

All oils will deteriorate over time with exposure to light, heat and air. The good news is there are lots of ways you can prevent and minimise damage to your oil(4). 

 To get the most out of your vegetable oil: 

• Avoid stockpiling. Keep an eye on the 'use by' date and ideally use within 12 months. 
• Store in a cool, dark place. Where possible, choose oil in a dark glass bottle or tin and keep it away from direct light. 
• Avoid reusing heated oils. As the oil darkens it develops off-flavours and becomes rancid.

Seed oils and inflammation

There is currently a lot of misinformation about seed oils and inflammation.  

Seed oils contain omega-6 fatty acids, a type of polyunsaturated fat, which are important for our health.  

However, it has been suggested that high intakes of omega-6 could promote inflammation in the body. 

Current evidence does not show that seed oils consumed in normal amounts lead to chronic inflammation. Also, there is no current evidence to suggest that seed oils lead to an increase in inflammatory markers in the body.  

Inflammation and heart health

Take home points

The best sources of heart-healthy polyunsaturated and monounsaturated fats are from whole foods that are close to how they are found in nature, e.g. nuts and seeds, avocado, olives and oily fish. 

For cooking, plant-based oils like olive, canola, high oleic sunflower and rice bran oils are better than butter and coconut oil.  

Extra virgin, cold-pressed oils (olive, avocado, canola, and high oleic sunflower) have more flavour, more colour and higher level of nutrients versus more refined oils.  

We recommend choosing the right oil for your budget and taking good care of it to prevent damage. 

A heart-healthy diet doesn’t come down to one specific food. What matters is your overall food intake.  

You can find out more information about fats and oils in our 2026 position statement, and on our information page on butter versus spreads. 

Fats and oils position statement 

Butter versus spreads  

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References 

1. Xia, M., Zhong, Y., Peng, Y. & Qian, C. Olive oil consumption and risk of cardiovascular disease and all-cause mortality: A meta-analysis of prospective cohort studies. Front. Nutr. 9, 1041203 (2022). 

2. Schwingshackl, L. et al. Impact of different types of olive oil on cardiovascular risk factors:  A systematic review and network meta-analysis. Nutr. Metab. Cardiovasc. Dis. 29, 1030–1039 (2019). 

3. O’Brien R. Edible Fats and Oils Processing and Applications. In: Handbook of Food Science, Technology, and Engineering, Volume Four. ; 2005. doi:doi:10.1201/9781420026337.ch155

4. Choe E, Min DB. Mechanisms and factors for edible oil oxidation. Crit Rev Food Sci Food Saf. 2006;5:169-186.