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  • Writer's pictureKarine

0014 - Stay away from vegetable oils!

Vegetable oils are one of the most popular ingredients used for cooking around the world. They can be found in most kitchen cabinets, restaurants and takeaways and are also widely used by the food manufacturing industry to make baked and deep-fried goods, margarine, condiments, sauces and salad dressings. What most people don't know is that these oils are extracted from seeds and heavily processed with chemicals, which make them very harmful for our health.

These vegetable oils include: canola (rapeseed), safflower seed, sunflower seed, corn, grape seed, soybean, sesame seed, peanut, cottonseed and rice bran oils. They are different from healthy fruit and nut oils, such as olive, coconut, avocado or macadamia oils that are obtained by just squeezing the fruits or the nuts.

Vegetable oils are heavily processed using chemicals

Whilst the seeds themselves are healthy in their natural, non-GMO and organic form, this is not the case of the heavily processed oils that are extracted from them.

The oil is extracted from the seeds using chemical solvents like hexane (derived from crude oil). It is then purified, refined and chemically altered with degumming agents, deodorisers and bleaching agents to improve the taste, texture and shelf life of the final product.

That should be enough to put you off consuming these oils ever again! If not, keep on reading...

Vegetable oils are easily oxidised

These oils are rich in polyunsaturated fats that react with the oxygen in the atmosphere and deteriorate into harmful compounds. This oxidation increases the formation of free radicals that can cause inflammation, wrinkles, cell membrane damage, arterial plaque build-up and disruption in our hormonal and immune functions. Oxidation can also increase our bad cholesterol and decrease our good cholesterol, which can raise the risk of cardio-vascular diseases.

According to Dr. Cate Shanahan, a study showed that eating French fries can give us the same arteries as an unhealthy 80 years old for 24 hours and can also reduce our cognitive functions. Well, don't blame the French, as the fries were actually invented in Belgium...

Vegetable oils can be hydrogenated

Many companies use hydrogenation to make vegetable oils solid at room temperature, to improve the texture, to make them more stable, more resistant to oxidation and to extend their shelf life. These hydrogenated oils are very convenient to make baked foods as they improve the taste and texture and are less likely to become rancid than other fats.

Unfortunately, most hydrogenated oils contain trans fats that are very harmful for our health. Consumption of hydrogenated and partially-hydrogenated fats is associated with inflammation, cancer, atherosclerosis, diabetes, obesity, immune system dysfunction, birth defects, impaired vision, sterility, problems with bones and tendons, increased risk of depression and cardio-vascular diseases... Aargh!!

Vegetable oils can contain trans fats that have been banned in the US

I have mentioned that hydrogenated oils can contain trans fats, but even non-hydrogenated vegetable oils can contain some trans fats. A study in the US found that the trans fat content of canola and soybean oils varied between 0.56% and 4.2%, without any mention on the label.

Some studies have linked consumption of trans fats to inflammation, higher bad cholesterol and lower good cholesterol levels, immune system dysfunction, liver issues, impaired blood sugar control, insulin resistance, obesity, increased risk of type 2 diabetes, cardio-vascular diseases and cancer. And trans fats can take months to be processed by our body!

These trans fats are so harmful that several countries have banned them or restricted their use. Effective from 2021, the European Union has limited trans fats to maximum 2% of total fats in foods, whereas The Food and Drug Administration (FDA) has completely banned trans fats from processed foods in the US, effective from 2020 or 2021 in some cases.

Unfortunately, the FDA has also agreed that foods with less than 0.5 grams of trans fats in a serving (a portion size that can easily be manipulated...) can disclose 0 gram of trans fats on the label! These hidden trans fats can add up quickly when you eat multiple foods and servings containing them.

So, to avoid foods that contain trans fats, check the ingredient list for “hydrogenated” or “partially-hydrogenated” oils.

Vegetable oils are high in inflammatory omega-6

Omega-6 ("O6") and omega-3 ("O3") are two types of polyunsaturated fatty acids. It is believed that humans evolved with an O6 to O3 ratio of about 1:1. But in the past century, this ratio increased to somewhere between 15:1 and 20:1 in standard Western diets.

O3 are found in fatty fish such as salmons and sardines. They reduce inflammation, are essential for brain and eye health and can improve our cholesterol profile. O6 are found primarily in vegetable oils, nuts and seeds, meat, fish and eggs. When eaten in a balanced ratio with O3, they can also promote health.

A high O6 to O3 ratio, on the other hand, contributes to chronic inflammation, which is a common factor in most modern diseases such as cardio-vascular diseases, cancer, diabetes, arthritis, obesity, Parkinson’s, Alzheimer’s and dementia.

Vegetable oils have either high O6 to O3 ratios and/or high amounts of O6 per 100g of fat (% in parenthesis): sunflower 312:1 (29%), sesame 57:1 (41%), corn 46:1 (53%), soybean 8:1 (50%), canola between 8:1 and 2:1 (19%). In comparison, olive oil, coconut oil, butter and lard are much lower in O6 (2 to 10%). So, if you have vegetable oils in your diet, you will have to swallow a lot of fish oil capsules to keep your O6 to O3 ratio balanced!

Vegetable oils can contain GMO

Over 90% of soy, corn, cottonseed and canola grown in the US are genetically modified.

There are serious health risks associated with GMO foods, including immune system malfunction, accelerated aging, leaky guts, insulin dysregulation, liver and kidney problems, toxicity, allergic reactions, cancer and loss of nutritional benefits.

Foods that contain vegetable oils

Over 90% of restaurants cook with vegetable oils. So if you are going out for dinner, ask for steamed vegetables and grilled meat/fish and melt butter or drizzle olive oil over them. Stay away from fried foods, dressings and sauces that usually contain these oils. Also, it is not unusual for restaurants and takeaways to keep the same vegetable oil in fryers for a week or more (yuck!), which worsens the oxidation.

Avoid consuming the most common sources of hydrogenated vegetable oils:

  • margarine, vegetable shortening and fake butters,

  • fried foods such as French fries, fried chicken and doughnuts,

  • baked goods such as cookies, muffins, cakes, pastries, pie crusts...

  • potato, corn and tortilla chips,

  • crackers,

  • pizzas, meat pies and sausage rolls,

  • packaged snacks,

  • pre-made dough,

  • microwave popcorn,

  • non-dairy coffee creamers,

  • infant formulas. Canola oil can be used in infant formula up to 31% of total fats in the US!

Healthy substitutes to vegetable oils

Fruit and nut oils are very healthy and tasty alternatives. These oils are extracted from fruits and nuts by cold-pressing or expeller-pressing, without the use of high temperatures or nasty chemicals.

These healthy fats provide building blocks for our cell membranes and hormones and are also needed to absorb the fat-soluble vitamins A, D, E, and K as well as certain minerals. The monounsaturated fats found in fruit and nut oils are known to enhance our cardio-vascular and immune functions and to offer protection against heart diseases. They can also help prevent depression, improve body composition, improve insulin sensitivity and blood sugar control and reduce cancer risk.

  • Unrefined coconut oil has a smoke point of 350°F/177°C and can be used for mid-temperature cooking, frying and baking. The refined variety is chemically bleached and deodorised and is not a healthy alternative. So, make sure you buy cold-pressed and virgin coconut oil that actually smells like coconut. This oil can help you increase your good cholesterol and is rich in medium-chain triglycerides (MCTs) that can increase metabolism and boost brain function.

  • Virgin and extra-virgin olive oils have a smoke point between 320°F/160°C and 374°F/190°C or even a bit higher for high quality extra-virgin olive oil. It is a good choice for most cooking methods. It does not oxidise nor go rancid during cooking. But its health benefits are best obtained when it is uncooked, for salad dressings or for drizzling on cooked vegetables or meat for instance. It is high in monounsaturated fats and has been associated with lower inflammation levels, reduced risk of cardio-vascular diseases and improved cholesterol profiles. Look for an organic extra-virgin cold-pressed olive oil in a dark glass bottle and avoid cheap olive oils that are sometimes blended with cheaper vegetables oils.

  • Avocado oil has a smoke point of 520°F/270°C, which is ideal for high-heat cooking such as grilling, searing and deep frying. The health benefits of avocado oil are similar to those of olive oil. It is also high in antioxidants and great for eye health. In France, it has even been recognised as a medicine against arthritis.

  • Unrefined red palm oil is made from the palm fruit. It is high in vitamin E and beta-carotene, stable at high heat and great for cooking and deep frying. But serious concerns have been raised about the sustainability of harvesting palm oil. So only buy organic unrefined palm oil that it is certified sustainable.

  • Nut oils (walnut, pecan, macadamia, hazelnut, Brazil nuts) are all very healthy options for cold-use seasoning. Note that peanut is not a nut: it is a legume and its oil is high in polyunsaturated fats (32%), vulnerable to oxidative damage at high temperatures.

  • Although this is uncommon, certain organic seeds oils are made using a cold-pressed or expeller-pressed process, rather than using chemical solvents and high heat. So if you really like your sesame seed or grape seed oil and can manage to find a high quality cold-pressed, pure, organic version, this can be a safe option.

  • Last, always store the fruit and nut oils in dark bottles and cupboards to prevent them from going rancid.

Animal fats are other healthy alternatives to vegetable oils. They are higher in saturated fats, which are needed for brain health, for our cell membranes and also to promote bone health, protect the liver from toxicity, help fight off infections and boost our immune system.

  • "Grass-fed" butter, compared to regular butter, is higher in O3 and other healthy fats such as alpha lipoic acid ("ALA") and conjugated linoleic acid ("CLA"). It supplies important nutrients and is lower in calories than oils. But it is not as good an option as clarified butter or ghee for high-heat cooking and deep frying as it contains trace of carbohydrates and proteins that can burn.

  • Ghee is a clarified butter used in India and Southeast Asia. It has a high smoke point (480°F/250°C) and has been shown to protect against cancer cell growth in some studies. It also contains healthy ALA and CLA. As for butter, prefer high quality organic grass-fed varieties.

  • Other animal fats, such as tallow, lard, chicken / lamb / duck / beef / pork fat drippings can also be used for cooking and deep frying. They taste great, add crispness and are very resistant to high heat. Again, make sure you buy animal fats from pasture-raised or grass-fed animals rather than from grain-fed animals that have a lot more polyunsaturated fatty acids in their fat stores.

If you want to learn more about vegetable oils, I recommend the video Vegetable Oils - The Untold Story and the US Dietary Guidelines and for my French friends, the article La vérité sur l’huile de tournesol (Vous allez être choqué).

I hope this blog will convince you to avoid vegetable oils as much as you can. Even if some studies only show an association with serious health issues rather than a direct causation, there are still plenty of evidences against them and they are not worth risking damaging your health. And cooking with butter, olive oil or coconut oil tastes so good, it would be a shame not to use these healthy alternatives!

Dietary fats are essential for health and well-being, but only if you consume healthy fats and avoid the toxic ones.

As usual, you can find references to studies and research papers here and my credentials here.

This article is for educational purposes only. It is not a substitute for professional medical advice and is not intended to diagnose, treat, cure, heal or prevent any disease or medical condition. See full disclaimer here.

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