Cooking Oils

Vegetable oils are a group of fats that are derived from seeds, nuts, cereal grains, and fruits. It is important to understand that not all these vegetable oils are good for you. 

Their health effects vary depending on what fatty acids they contain, what plants they are extracted from, and how they are processed.

Scientists found that heating up vegetable oils led to the release of high concentrations of chemicals called aldehydes, which have been linked to illnesses including cancer, heart disease and dementia.

But compared, heating butter, olive oil and lard in tests produced much lower levels of aldehydes. Coconut oil produces the lowest levels of harmful chemicals.

All processed or refined oils when you start messing around with them, exposing them to high amounts of heat in the frying pan or the oven, undergo a complex series of chemical reactions which results in the accumulation of large amounts of toxic compounds.

Let’s look at vegetable oils, the most common of cooking oils. Many of these oils are high in omega-6 fatty acids. Oils, high in omega 6, that fall into this category are soybean, corn, cottonseed, sunflower, peanut, sesame, palm and rice bran. 

Not only do they contain fatty acids, but they are also high in saturated fats which can spike cholesterol levels.  These omega-6 fatty acids are overriding the essential omega-3 fatty acids that keep the brain healthy.

Background

There are many vegetable oils sold in grocery and specialty shops. They are more cost-effective to produce and have a longer shelf life because of their processing methods, however, these methods are unhealthy. 

“Vegetable oils” are made of many different plant-containing seeds from which oil must be extracted. These oils are mass-produced with seeds being extracted with solvent, and other chemicals, which can be mixed into oils and ingested.

These oils are sold in their “pure” form, though nothing is pure about them, and most of the products are not required to list ingredients and are often sneaked into processed foods like salad dressings and marinades. So, read food labels to see what oils are in products on your shopping list. 

Stay away from products with terms such as “partially hydrogenated” or “hydrogenated”. Hydrogenation is a chemical process that converts liquid vegetable oil into solid fat and can contribute to heart disease.

Look for oils that utilize more natural processing practices, by pressing or crushing plants or seeds, instead of extracting them with chemicals.

 Healthier choices would be walnuts, avocados, and, of course, olive oils. Olives are naturally crushed for their healthy oils. These are low in unsaturated fatty acids and have anti-inflammatory and antioxidant benefits, beneficial when cooking or preparing food.

There seems to be global pressure from both consumers and food industries regarding refined oil quality to meet the established specifications for food safety. The oil must be odourless and rather neutral in taste, limpid, and colourless, and it must be free of contaminants.

 Treatment that eliminates undesirable and toxic components in crude oils is known as “refining”  Refining is practically mandatory for crude oils that cannot be consumed as virgin oils to provide a product with an attractive appearance, a neutral taste, and more resistance to oxidation.

Although refining extends oil shelf life, it has several disadvantages. One of the main disadvantages is the loss of substances responsible for healthy, pharmaceutical properties and technological interest in the oils, such as tocopherols, phospholipids, squalene, polyphenols, and phytosterols [. 

Another notable disadvantage of refining is the formation of undesirable compounds such as glycidyl ester, 3-MCPD-esters, harmful trans-fatty acids and polymeric triacylglycerols. These can directly influence the safety level of refined oils.

Saturated vs. Unsaturated vs. Trans Fatty Acids

Cooking oils and margarine all contain an artificial fat known as a trans-fat. Most trans-fat is formed through an industrial process known as hydrogenation, where hydrogen is added to vegetable oil.

 In the case of vegetable oil, it is partially hydrogenated which gives it a longer shelf life. For margarine, it is hydrogenated until it becomes solid at room temperature.

Corn oil, Canola (also called rapeseed) oil, Cottonseed oil, Soy oil, Sunflower oil, Safflower oil, Grapeseed oil and Rice bran oil are 8 of the unhealthiest vegetable oils. 

These oils contain a high percentage of polyunsaturated fatty acids (PUFAs) – which are unstable and break down rapidly when exposed to chemical stress and heat.

The Downside of Omega-6

Vegetable oils contain high levels of omega-6. Research suggests that the high volume of omega-6 can essentially bump the important omega-3 molecules out of the receptors in the brain. This is thought to be a contributing factor to the increase in mental health issues.

The Good Fats from Plant Oil

All cold-pressed plant oils, like extra virgin olive oil, have health benefits, but when it comes to cooking it seems the two natural oils that contain saturated fat are the best for cooking. Saturated fats are needed for healthy cell membranes in our organs, muscles and in our brains.

Oils that are high in polyunsaturated fats are susceptible to oxidation, both on the shelf and inside your body.

Butter

Real butter is good for you and fairly nutritious. It contains Vitamins A, E and K2. It is also rich in the fatty acids Conjugated Linoleic Acid (CLA) and Butyrate, both of which have powerful health benefits.

Organic butter on the other hand has the ideal balance of a 2:1 ratio of omega-6 to omega-3. It is also a good source of short and medium-chain fatty acids, as well as your fat-soluble vitamins A, D, E and K. 

Butter from grass-fed cows contains a Conjugated Linoleic Acid (CLA) a compound that can help to protect against different types of cancer and helps the body build muscle instead of fat. 

The cholesterol in butter is a good type that can also be used by the body for cellular function. Moderation is the key to diet, and you can overdo anything, especially something that is high fat, high calories, and tasty.

Hydrogenated vegetable oils are high in trans-fat, which has been associated with various health problems. Found in certain types of margarine, ice cream, and cookies.

Margarine is an artificial butter made from vegetable oil. It is saturated with trans fats that are harmful to the body. Stay away!

Monosaturated oils (MUFA)-rich oils are widely considered the safest fats to cook with—research suggests they may help curb inflammation, improve blood lipids like cholesterol, and support cardiovascular health.

Coconut oil

Over 90% of the fatty acids in it are saturated, which makes it very resistant to heat. Coconut oil; doesn’t contain any omegas, but it is an amazing source of medium-chain triglycerides (MCT). 

This rare form of fat is highly beneficial; it is quickly and easily digested; it helps to support the immune system and metabolism as well as providing the brain and body with a great source of energy.

• Smoke point: 350°F (unrefined) to 450°F (refined)
• Good for: Add unrefined coconut oil to smoothies, coffee, and raw desserts, or let it melt onto already cooked dishes, where its flavour can shine. Use naturally refined oil for sauteing, stir-frying, baking, and roasting. 
• How quickly it goes bad: Coconut oil should last about 2 years in your pantry, if you keep the jar shut tight.
• Fat breakdown: 93% SFAs, 4% MUFAs
• Taste: Rich, sweet, nutty

MCT is unique in the way that it goes directly to the liver to support metabolic processes and it doesn’t need enzymes for absorption. It can help one to lose weight, and improve brain function and it is a strong natural anti-inflammatory.

Coconut oil is also a good source of fuel for the steroid hormone system, helping to support stress, fertility and good thyroid function. 

However, it is important to note that coconut oil is made up of 75% fatty acids and could potentially be LDL-raising, so moderation is advised. 

Make sure to choose virgin coconut oil. It’s organic, it tastes good and it has powerful health benefits. 

The fats in coconut oil can also boost metabolism slightly and increase feelings of fullness compared to other fats. It is the only cooking oil that made it to the list of superfoods

Extra Virgin Olive oil

Olive Oil is considered to be one of the healthiest options to add to food, and it can be used for cooking at a moderate temperature, not higher than 180°C. Extra virgin olive oil has a lower smoking point of 163°C. Avocado oil should not be used for cooking as it has the highest smoking point of 256°C.

EVOO’s low acidity indicates stability. When an oil is degraded through refinement or contact with oxygen, the triglycerides break down and form free fatty acids (aka free radicals). 

The presence of free fatty acids causes the acidity to climb. Since EVOO has acidity below 0.8% (there are very few free fatty acids. When the EVOO cooks, it stays more stable than other oils and shows only trace levels of trans fats.

There are several grades of olive oil, which vary in terms of their nutritional content and the amount of processing that they undergo.

  The three main grades of EVOO include:

• refined olive oil
• virgin olive oil
• extra virgin olive oil

Extra virgin olive oil is the least processed variety and is often considered to be the healthiest type of olive oil. It’s extracted naturally and then refined to have a certain pureness and desired taste or smell.

Make sure to choose quality Extra Virgin Olive Oil. It has much more nutrients and antioxidants than the refined type. Plus it tastes much better.

Keep your olive oil in a cool, dry, dark place, to prevent it from going rancid.

Extra Virgin Olive Oil, or EVOO, is one of the healthier choices when selecting a cooking oil. In general, olive oil contains antioxidants including Vitamin E which are healthy for the body, inside and out. 

Extra Virgin Olive Oil is derived from the first pressing of the olives, delivering more powerful antioxidants that fight free radicals and provide more natural protection against oxidation, thus keeping the product and its benefits fresher and longer.

• Smoke point: 325 to 375°F
• Good for: Drizzling on top of salads, toasts, pasta, or grain dishes. Light to medium-high heat cooking like sauteing and stir-frying, and some roasting and baking.
• How quickly it goes bad: use within 6 months the bottle (some sources recommend it within 3 months for maximum nutrition and freshness). 
• Fat breakdown: 74% MUFAs (or more), 10% PUFAs, 16% SFAs
• Taste: Grassy, pepper

Avocado Oil (Unrefined and Naturally Refined)

Avocado Oil is pressed from the flesh of the avocado fruit and like olive oil is abundant in oxidative stable MUFAs (predominantly oleic acid) and a variety of phytochemicals.

Diets rich in avocado oil have also been associated with reduced triglycerides, total cholesterol, and LDL cholesterol.

• Smoke point: 350°F to 400°F (unrefined), 480°F to 520°F (naturally refined)
• Good for: Virgin avocado oils can be used just like EVOO. Naturally refined avocado oil is great for searing, broiling, grilling, frying, and high-heat baking and roasting.
• How quickly it goes bad: Use within 6 months of opening the bottle. 
• Fat breakdown: 71% MUFAs, 14% PUFAs, 14% SFAs
• Taste: Vegetal, buttery

There’s also the matter of price. Not everyone can afford to use top-shelf oils for everything—and that’s OK. In that case, you could prioritize healthy, unrefined oils for raw applications (e.g., drizzling over finished dishes, using in salad dressings or DIY dipping oils) where they will retain their maximum concentration of beneficial phytochemicals while using a less expensive but still heat-stable oil for cooking, like high-oleic sunflower oil. 

To make sure that your fats and oils don’t go rancid, it is important to keep a few things in mind.

 Don’t buy large batches at a time. Buy smaller ones, that way you will most likely use them before they get the chance to damage.

When it comes to unsaturated fats like olive, palm, avocado oil and some others, it is important to keep them in an environment where they are less likely to oxidize and go rancid.

 The main drivers behind oxidative damage of cooking oils are heat, oxygen and light.

 Therefore, keep them in a cool, dry, dark place and make sure to screw the lid on as soon as you’re done using them.

 Cooking oils are complicated, but nutritious options exist for every application. Once you know what makes a healthy cooking oil (in terms of fat profile, level of refinement, and smoke point), it gets way easier to choose one (or a few) that fits your culinary needs and health goals.

 And remember – These oils should make up a relatively small percentage of your caloric intake, so they’re not going to make or break your health (your overall diet and lifestyle will do that) —they’re just one additional way to fine-tune it. 

Polyunsaturated fatty acids (PUFA’s)

Saturated fatty acids (SAF’’s)

Monounsaturated fatty acids MUFA’S

Ref: Refining Vegetable Oils: Chemical and Physical Refining PubMed/Central