4 Reasons to Avoid Cooking with Vegetable Oils

When making dietary changes, adding more vegetables is a quick and easy way to get the ball rolling. Next, you might think, “I’ll add some vegetable oil, too,” for a few more veggie bonus points. So you pat yourself on the back, thinking you’re doing the right thing, but unfortunately, you’d actually be wrong, very wrong. Adding vegetable oil to your plate or skillet can do your body far more harm than good, so drop the “pure vegetable” oils like Mazola and Crisco, and listen up. It’s time to get them out of your life and here’s why:

1) Vegetable Oils Don’t Involve Vegetables

Now hear this: there’s no vegetable benefit to be gained from vegetable oil. Many consumers mistakenly believe that cooking oil, as long as it says vegetable on the label, is all good. In fact, the unhealthiest and most commonly used oils on the market contain no vegetables at all.

So-called ‘vegetable’ oils are actually made from tough seeds and legumes that were originally grown for industrial use, not human consumption. These seeds must be treated chemically in order to be processed into a pourable, somewhat more human-friendly liquid (and often deodorized too, to mask the terrible smell from the chemical processing).  

Among the industrial/vegetable oils to jettison: canola, corn, cottonseed, safflower, sunflower, rice bran and soy oil.  At the opposite end of the health spectrum are the good-for-you fruit and nut oils, including olive oil, walnut oil, coconut oil, and avocado oil, which are simply pressed to extract the oils, without caustic chemical processing.

2) Vegetable Oils Are Unstable – Causing You Damage

Another reason not to love vegetable oils? They’re unstable, which makes them inflammatory. Saturated fats are more stable fats because of their molecular structure. Unsaturated fats are less stable—and polyunsaturated fats are the least stable of all.

When a fat is unstable, that means it is vulnerable to oxidation—that is, to penetration by oxygen molecules. Oxidation causes fats to go rancid and to create free radicals: atoms with an odd number of electrons that can cause extensive damage to your cells. Any fat can be oxidized and create this damage, but because polyunsaturated fats are so unstable, they are the most prone to it.

Polyunsaturated fats like the industrial oils can become rancid simply from exposure to light through a clear glass bottle, which means that it’s basically gone bad even before you take it home from the store. Heat also oxidizes these types of fats, which means that if you eat anything cooked in an industrial oil, you’re exposing yourself to free radicals that can cause quite a lot of cellular damage.

3) Vegetable Oil Inflames Your System

Vegetable oil doesn’t always have to be in liquid form to do damage. It also turns up in thicker, glue-like form, in vats of Crisco, margarine or tucked into thousands of processed foods. These products are made with partially hydrogenated vegetable oils or partially hydrogenated fats, aka., ‘trans fats,’ and are, not surprisingly, also horrendous for health. 

To make trans fats, manufacturers inject extra hydrogen into vegetable oils, which extends product shelf life, in some cases, indefinitely. Great for product shelf life but lousy for yours, promoting system-wide inflammation throughout your body and setting the stage for heart disease, diabetes, autoimmune conditions, and cancer down the road.

Also keep in mind that ‘trans-fat free’ does not mean vegetable oil free, just that it’s free of partially hydrogenated vegetable oils – and in some processed foods both trans fats and vegetable oils will be present – truly the worst of both worlds. And a trans fat-free designation doesn’t mean that much either, because here in the U.S., any product can call itself ‘trans fat-free’ as long as there’s fewer than .5 grams of trans fat per serving. Sounds O.K. till you realize that you can still pile on the stuff should you grab an extra cookie (or three) or another handful of those ‘trans fat-free” chips. 

Pretty sneaky, eh? But, fortunately, not for too much longer. In 2018, 0 grams of trans fat per serving will be the law of the land, when the FDA ban (at last) goes into effect. Regardless, ditch the processed foods – they’re a significant source of trans fats and hidden vegetable oils, both of which bring with them a lot of heartache.

4) Vegetable Oil – Rich in Gut and Body Disrupting Toxins

Whether you’re shopping at Whole Foods or Wal-Mart, on those shelves you’ll find an enormous array of cleverly marketed, beautifully packaged, healthy-looking ‘industrial oils’ like canola, corn, cottonseed, safflower, sunflower, rice bran and soy oil. 

Don’t be fooled by the pastoral packaging – what you’re really looking at  is yet another factory-farmed faux food, grown in nutrient-barren soil, so again, there’s little benefit to be had. What’s more, these mass-produced, originally-for-industrial-use oils weren’t even part of the human diet until the early 20th century when manufacturers found ways to process them into ‘edible’ form as a cheap replacement for animal fat and butter. But among the truly unappetizing, health-threatening issues associated with these oils, the ones that concern me most are:

1.   Corn, cottonseed, safflower, sunflower, rice and soy are heavily-pesticided crops, the majority of which have been genetically modified (GM) to withstand all that chemical spraying – and you wind up eating them. (Toxins, anyone?).  

2.   These GM oils help kill off your healthy bacteria and alter your microbiome which leads to gut problems, inflammation, weight gain and a host of other ills.

3.   They also throw off your ratio of Omega-3 and Omega-6 fats. Ideally, the ratio of Omega 6s to Omega 3s should be 1:1. But our modern consumption is more like 10:1 or even 25:1 due, in large part, to the use of industrial oils in processed and prepared foods. When the balance is off, the overabundance of Omega 6s can trigger inflammation.

In other words, vegetable oils can really do damage – so the most prudent path is to keep the stuff out of your body, whether it’s liquid, paste or baked-in form. 


1.   Don’t be fooled by pretty packages, great graphics, and phrases like ‘no trans fats’, ‘pure vegetable’, ‘all natural’ and so on.

2.   Instead, know your oils, buy the highest quality possible, and look for organic or small producer or artisanal batches, to minimize and/or eliminate toxin and GM concerns. 

3.   On the good-for-you list are the fruit and nut oils, including olive oil, walnut oil, coconut oil, and avocado.

4.   Whenever possible, opt for oils that are cold-pressed. That means they’ve not been exposed to nutrient-neutralizing high heat and chemical solvents. 

5.   Extra virgin olive oil (EVOO) is great for everyday use. High-quality EVOOs will be more expensive than unhealthy industrial oils – but think of the extra cost as a tasty and worthwhile investment in your health.

6.   Look for EVOO in dark glass bottles to shield it from light to prevent rancidity. You can also wrap the bottle in foil as an added layer of protection – and don’t bother with oils in plastic bottles.

7.   ‘EVOO’ contains good fat making it a very healthy choice. EVOOs are great for salad dressings, sauces, and cooking at lower temperatures, like light sautéing.

8.   For high-temperature cooking, use fruit oils like coconut oil or avocado oil, and saturated fats like lard (yes lard), duck fat, ghee and grass-fed butter. To avoid a coconut flavor when cooking with coconut oil, use expeller pressed.

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