Inside Scoop: Did you know that the process of heating during cooking, can affect the structure of oils? Here is the healthiest oil for cooking.
This post was submitted by Paul Jenkins, MSc in Applied Chemistry and founder of DNA Lean.
The use of cooking oils has become more popular than ever; oils are used in a whole manner of different ways, from sauté, pan-frying, baking, deep frying and so and so forth. There is also a wide array of oils that are sold for cooking.
The most popular cooking oils by consumption are:
- Palm oil
- Soybean oil
- Sunflower seed oil
- Palm kernel oil
- Peanut oil
- Cottonseed oil
- Coconut oil
- Rapeseed oil
However, despite the popularity of these cooking oils, most on this list are not good to consume in any form let alone heating on your stove and using them for cooking. For example, peanut oil and cottonseed oil both lack in nutrition, they don’t contain any essential omega 3 fats (alpha-linolenic acid) and are significantly high in saturated fats which can be problematic when consumed in excess.
Did you know that the process of heating during cooking, can significantly affect the molecular structure of fatty acids?
In this article, you will learn the basics of health oils and why I don’t recommend frying with oil, along with how to choose the healthiest oil for cooking and the best oils for your health. I will also be covering other questions such as, what oil has the highest smoke point.
What makes an oil healthy and nutritious?
Oils are made of various different fatty acids, some of these are good, and others can be harmful to our health. Good fats are vital for maintaining your health. For example, good fats help combat inflammation, help maintain good joint health, are good for your heart and facilitate absorption of fat soluble vitamins such as vitamin D.
Although all fats are listed as having 9 calories per gram, this is no way a measure of how good or bad they are for your health. Trans fats for example have been linked to various diseases, yet another example of why calorie counting isn’t accurate.
Some good fats are essential, that is your body cannot endogenously synthesise them. However contrary to popular belief, this is not the case with good EPA omega 3 oils found in fish; these fats are not essential. So, while EPA found in fish has a lot of health benefits, it is not technically essential because it can be synthesised from Alpha Linolenic Acid (ALA).
Essential fatty acids have 2 classes; omega 3 & 6. Everything else your body can synthesise from these two sources. It is absolutely crucial to your life that you consume these fats, and in the right ratio, which I will touch upon later on in this article. Healthy and nutritious oil must have both omega 3 & 6 fats and be low in saturated fat.
The structure of fats
Fats are biologically active molecules; their structure and shape makes them so important to your health. You could liken them to “keys” that fit your body’s biological “locks” which open the door to a whole world of incredible bio-chemistry.
The problem herein lies; good fats are perfectly packaged in nature to prevent them from “going-off”. Take pumpkin seeds for example, their essential omega fats are contained inside a seed protected from air and light, where they can’t be oxidised.
Unsaturated fats are highly reactive, this means that when exposed to light and oxygen they readily oxidise, altering their molecular structure and thus changing their biological function.
If a fat is unsaturated it means that it has at least one carbon atom in its chain that is available for bonding with a hydrogen atom from your tissues. Therefore, unsaturated fats are biologically active and are readily incorporated into your structure.
The bottom line is that heating oil denatures the structure of essential fatty acids, and because these get incorporated into your structure, this results in the denaturing of your structure on a cellular level.
Heat damages good oil
As with anything commercial, the primary goal is to make money. The food industry is no different, “big food” is in the business of making big profits. The commercial cooking oil industry is a classic example of this; oils are not produced with health in mind. In fact, more health problems originate from the consumption of damaged oils, compared to any other area of nutrition.
The problem lies in the manufacturing processes used in the production of commercial cooking oils. These processes yield nutritionally inferior oils that look pure, have no smell, and come with an extended shelf life that lasts for years. Sure, they sell well, but at what cost?
Commercial oil production involves a ton of damaging processes; vegetable oils get treated with sodium hydroxide, phosphoric acid and bleaching clays. These chemical processes turn the oil rancid which causes it to smell, and of course you can’t have smelly cooking oil because no one would buy them.
The “solution” is to heat the oils to frying temperature which removes the odour, but remember unsaturated fats are heat sensitive, so the heat damages the oil and denatures (changes the structure) the fatty acids. The best part, after purchasing your oil, you are then going to cook and fry with it, in the presence of light and oxygen. This completely destroys the oil.
What is smoke point?
Smoke point is quite literally the temperate point at which the liquid oil starts to smoke and turn gaseous. As you can imagine different oils have different smoke points and some are much higher than others. If you heat an oil right up to its smoke point, the fatty acids will be well and truly destroyed.
Although some oils may be more heat resistant than others, smoke point is not a particularly good measure of choosing an oil. For example, unrefined coconut oil has a significantly lower smoke point than that of rice bran oil. Yet even at around 160 degrees (just under coconut oil’s smoking point) the fatty acids in rice bran oil become denatured.
When you heat oils even to a low heat, around 160 degrees C, this is when the denaturing occurs.
What is the Healthiest Oil for Cooking?
There are some oils that are less toxic, but none are particularly good to fry with. In fact, the only type of fat that is inert to air and light, is saturated fat. These fats are semi-solid or hard at room temperature, fats such as; coconut oil, butter, palm oil and shortening.
These are the most heat stable, but as I explained earlier, some saturated fats aren’t the most nutritious and aren’t desirable in high amounts. At best your body can use them as a fuel source but if you don’t burn them at that time, they will soon accumulate in your adipose tissue.
The top 5 vegetable oils – based on ALA & LA content
These are the top 5 best vegetable oils, In terms of essential fatty acid content (omega 3 & 6);
- Flaxseed (Linseed)
2. Pumpkin seed
Balancing omega 3 & 6
Today, a substantial amount of people have fallen deficient in omega 3 fats. This is due to a number of reasons such as not eating enough omega 3 rich foods in the first instance, but is also caused by the destruction of essential fats during the manufacturing of commercially manufactured cooking oils.
In fact, for most people omega 6 fatty acid consumption is at least double that of omega 3, but for optimal health you need the right balance, this is 2:1 omega 3/omega 6. There are some health oils that are produced from a blend of different vegetable oils. If you purchase one of these, look for a 2:1 ratio of omega 3 & 6, this is best.
How to choose a good quality vegetable oil
The rule of thumb here is to only use oils that are left in their natural state, that is raw, unprocessed oils, ones that are labelled either cold-pressed, raw, unrefined or virgin oils. However, bear in mind that these types of oils tend to go rancid quicker than processed oils. Don’t worry if the shelf life is much shorter than their processed counterparts; this is actually a good sign.
It is also important to look for oil that has been packaged/bottled in an atmospherically protected environment, whereby the fatty acids have been preserved from oxidation.
But, as we mentioned vegetable oils are not good or meant for cooking or heating which brings us to a staple oil of the Mediterranean diet, olive oil and one of the most popular oils in the past few years, coconut oil.
Olive Oil vs. Coconut Oil
If we were asked to choose the healthiest oil for cooking it would most definitely be olive oil with coconut oil and avocado oil coming at close seconds.
Olive oil is very high in antioxidants which help fight against the damage to the oil caused by heating, and has been found safe for cooking on low and medium temperatures such as sautéing and baking. Being high in more stable saturated fats, coconut oil is a close second. It is a little more stable than olive oil, but doesn’t come close to the number of antioxidants that olive oil contains. Butter is another safer alternative.
Fill out the below form to download the full list of the healthiest oils for cooking and the safest temperatures for each oil.
Omega 3 & 6 (ALA) α-linolenic and linoleic acid (LA)Essential cis-fats found in vegetable oils are biologically active and are required to maintaining your health. These healthy fats are unsaturated which means that due to their structure and chemistry, are liquids at room temperature. These fatty acids are hyper-sensitive to heat, oxygen and light.
My advice would be not to cook everything with oil in the first place, and use a small amount of grass fed butter, coconut oil or olive oil when needed.
Another wonderful alternative is to cook with water, steam or broil your food. Then you can incorporate nutritious oils such as olive oil, flaxseed (linseed), pumpkin seed, walnut, hemp or others by drizzling it on top. You can also make you own salad dressings, add them into yoghurts or simply spoon them over your food AFTER it is cooked – get creative!
Paul Jenkins is the founder of DNA Lean, an innovative line of sports supplements designed to provide the average gym-goer right up to the professional athlete good, honest, and research-backed supplementation for optimal performance and hormonal health.
Paul has almost 20 years’ experience in sports nutrition and coaching. Although he studied an MSc in Applied Chemistry, he firmly believes that food is medicine and that natural ingredients from plants and herbs can better work in harmony with the human body to improve performance, rather than resorting to pharmaceutical drugs.