Understanding what makes a cooking oil (un)healthy can be confusing.
There is a lot of misunderstanding about fats; one of them is that a healthy cooking oil should contain as little fat as possible. As a result, many people cook with the wrong kind of fats, thinking that they are doing their health a favor, when the opposite is true.

There are fats that are just not healthy in general and shouldn’t be consumed at all.
Then there are fats that are good for us, but are so sensitive to heat that they actually become unhealthy when we cook with them.
And there are a few fats which are good for you in both the unheated and heated states.

 

When we choose an oil to cook with, we need to understand how both states impact our health;

1. unheated: for example when you pour raw, room temperature oil over your salad

2. heated: when you use an oil to cook or fry food with.

 

First, let’s take a look at the different types of fat.

 

Not all fats are the same

We need good fats, it’s as simple as that. They assist with many important body functions related to our brain, cells, metabolism, blood, hormones, skin, digestion, teeth and lungs.
It’s important to know though which fats are good for us and which to avoid.

There are different types of fat:

 

– Monounsaturated fats – found in avocados, olive oil, peanuts and other foods.

– Polyunsaturated fats – plant sources: nuts, seeds and vegetable oils.
Animal sources: salmon, mackerel and herring.

– Saturated fats – animal sources: meat, dairy products and eggs.
Plant sources: coconut oil, cacao butter and palm kernel oil.

– Trans fats – a result of chemical processing and bad for your health.
They are found in many processed foods such as chips, fried foods, cookies, candies, some types of margarine and anything labeled ‘’(partially) hydrogenated’’.
They raise bad cholesterol levels (LDL) and increase the risk of heart disease, diabetes and cancer.

 

It’s crucial to know what makes a cooking oil (un)healthy by understanding what happens to it when it is heated.
If you follow a raw food diet, you can skip this part. For those of us who cook regularly; this is for you.

 

Oxidation

When a fat is heated, it changes its property. A fat that isn’t heat-stable is prone to a chemical reaction called oxidation.
Oxidation happens when certain fats interact with heat, oxygen, moisture and light. This results in harmful free radicals that can cause serious damage to our body – especially the brain, heart and liver.

Every oil oxidizes at a certain temperature, the key is to choose those fats that are most heat-resistant and make a healthy cooking oil.

 

1. Oils high in polyunsaturated fats such as sunflower, soy and corn are very sensitive to heat. They oxidize easily and should not be used to cook with.

” Considerable evidence has accumulated over the past two decades that heated cooking oils, especially polyunsaturated oils, may pose several types of health risks to consumers of fried food and even people working near deep fat fryers.
Heat degrades polyunsaturated fatty acids to toxic compounds; saturated and monounsaturated fatty acids are resistant to heat-induced degradation. ”

More about this in the scientific report Health effects of oxidized heated oils

Vegetable oils such as soybean, corn, sunflower, canola, grapeseed and peanut are usually also heavily processed and already oxidized when you buy them. Unless they are organic, they contain chemicals and pesticides and are often genetically modified (GMO).

It’s best not to use these oils at all.

 

2. Oils high in monounsaturated fats such as avocado oil and olive oil are more stable than polyunsaturated fats, but they are not recommended for cooking.

It is better to add them to warm food immediately after cooking.

Extra virgin olive oil and sesame oil are exceptions to this and considered safe for brief low temperature cooking. This is due to their high content of antioxidants which protect against oxidation.

 

3. Saturated fats such as coconut oil and butter are the most heat-resistant fats, which makes them safe oils for cooking.

For high temperature cooking or deep frying it is recommended to use a good quality refined coconut oil, because it handles high temperatures a bit better than unrefined coconut oil.

 

I designed this fat chart to help you better understand how much saturated, monounsaturated and polyunsaturated fat each cooking oil contains. It makes it easier to get the whole overview and choose a healthy cooking oil.

 

A fat chart to learn about what makes a healthy cooking oil

 

Why coconut oil is a healthy cooking oil

Coconut oil consists of 92% saturated fat. That sounds like a lot, but the kind of saturated fats in coconut oil are actually good for you.
As you can see in the chart above, coconut oil contains the highest amount of saturated fats of all cooking oils, which makes it the most heat-stable fat to cook with.
But there is more about what makes coconut oil a healthy cooking oil;

The fatty acids in coconut oil called MCT’s -Medium Chain Triglycerides- are packed with health benefits.
Instead of being stored in the body, they are metabolized in the liver and immediately used for energy. Another part of them converts into ketones which are a valuable source of fuel for our brain, heart and muscles.

Due to the fact that MCT’s a) don’t get stored in the body as other fats typically do and b) help to speed up metabolism, they actually help burn fat. A balanced consumption of these healthy fats can have a positive effect on weight control and help you lose weight, especially in the abdominal area.

The MCT’s antiviral, antimicrobial, antifungal and antiparasitic properties help destroy viruses, bacteria and fungi. They assist in body detoxification which is so important for good health.

MCT’s also help with the absorption of important fat-soluble vitamins, minerals and anti-oxidants such as vitamins A, D, E and K.
So when you’re making a green leaf smoothie or a mango shake, adding a bit of coconut oil to it will help you get the maximum nutritious value!

 

Lauric acid

Lauric acid which is considered the most important of the MCT’s, forms about 50% of the MCT’s in coconut oil. The rest are for the most part caprylic acid and capric acid.

Coconuts are the main plant-based source of lauric acid found in nature – another source of lauric acid is a component of.. breast milk! The first and essential building source of babies born into this world.
Isn’t it amazing how nature works? It gives us exactly what we need.

 

What you need to know about ”liquid coconut oil”

It is important to know that it’s lauric acid which makes coconut oil so heat-resistant. The other MCT’s caprylic acid and capric acid are not heat-resistant.

There is a type of chemically processed coconut oil named liquid coconut oil which has all or part of the lauric acid removed.
This is why this oil stays liquid even when refrigerated.

While it might seem convenient that it’s always liquid, the natural property of coconut oil is to solidify at low temperatures and to melt at high temperatures.
Without the lauric acid, it ceases to be heat-resistant and is not healthy to cook with. This type of coconut oil actually isn’t really coconut oil anymore and is not a healthy cooking oil.

Liquid coconut oil is a confusing product name, because coconut oil does get liquid naturally when temperatures rise. It has a melting point of 24° C / 76° F and it can easily go between solid and liquid without going bad or altering the oil’s quality.

My advice is to always read labels and only use high quality coconut oils which are naturally heat-stable.

 

To conclude

Good fats are essential for our health. We need them for proper functioning of our brain, bones, cells, muscles, blood, hormones, skin, digestion, teeth, lungs and metabolism.
They also play an important role in the absorption of vitamins and minerals.

While some oils might be healthy when unheated, it doesn’t mean that they also make a healthy cooking oil.

The most heat-stable cooking oils are those who contain a large amount of saturated fats.
Oils high in polyunsaturated fats are very sensitive to heat and should not be used to cook with.

Coconut oil is a multi purpose oil that can be used for cooking, frying or baking, while the oil stays stable and wholesome as a healthy cooking oil should.

Like with all products; use in moderation and with good sense for a well balanced, healthy diet!

If you want to read more about the health effects of oxidized heated (polyunsaturated) oils, I recommend this scientific article by M. Grootveld, C. Silwood, P. Addis and M. Viana. You can download the PDF for free on ResearchGate.

These two articles will guide you through everything you need to know about choosing a virgin coconut oil and refined coconut oil.  I also explain about the various production methods of coconut oil and their differences in nutritional value.