Vegetable oils – Friend or Foe?


Vegetable oils such as canola oil, safflower oil, corn oil, soy oil etc. are very reactive to oxygen, and go rancid when heated even at low temperatures. Once oxidized, these fats cause free radical damage in our bodies, which has been linked to cancer, heart disease and diabetes.

According to the animal research of Dr. Kenneth Carroll, “…the more polyunsaturated fats were in the diet, the more they were cancer promoting; and the more saturated fats were, the more they were cancer reducing…” Yet we are told by such organizations as the American Heart Association that these polyunsaturated oils are the healthy oils to eat and cook with.

In actual fact, we were only meant to consume vegetable oils by eating the nuts and seeds that they come in; the nuts and seeds also contain the antioxidants that prevent the oxidization of the fats.

Vegetable oils are refined with solvents and heat, making them toxic and rancid. Deodorizing compounds are added to cover up the smell, and voila – they will stay on the store shelf for months looking deceptively beautiful. 

Even in their unrefined form, these polyunsaturated oils cannot be recommended even in salad dressings, as they are sensitive to light. Polyunsaturated vegetable oils are also most frequently turned into trans-fats, so pretty much any time you see any vegetable oils listed on an ingredient list in a packaged food or a recipe, you would be doing yourself a huge favour in the long run by not eating it.

The best fats for cooking are organic pasture-fed raw butter or ghee, organic virgin coconut oil, organic, pasture-fed beef tallow, and unrefined extra virgin organic olive oil (low to medium temperatures only).

Enig, Mary; Know Your Fats: The Complete Primer For Understanding the Nutrition of Fats, Oils, and Cholesterol Bethesda Press, Silver Spring, MD, 2003.

Fallon, Sally and Enig, Mary; Nourishing Traditions: The Cookbook that Challenges Politically Correct Nutrition and the Diet DictocratsNewTrends Publishing Inc., Washington, D.C., 2001


  1. Rebecca Cody said,

    September 18, 2011 @ 10:53 am

    You’re so right! And what people don’t always understand is that deep-fried foods like french fries, onion rings, etc. are cooked in oil that is heated and reheated every day to high temperatures. In a previous life my former husband and I owned a tavern, and we only changed the oil in the fryer monthly! We didn’t do the volume of business of a fast food restaurant, but still, I shudder to think of it.

    Any time you heat unsaturated oil, even at home, high enough to fry anything, much of it turns into trans fats!

    People put flax seeds into muffins and other cooked foods, but omega 3 oils are very delicate and should never be heated.

  2. lisa marie said,

    September 18, 2011 @ 12:40 pm

    Hello Vreni,
    Wouldn’t you also say that extra virgin is also important for olive oil, in addition to “unrefined organic”. (Or were you covering that in unrefined?)

    Thanks for commenting on omega-rich seeds like flax and that they shouldn’t be heated – this is very hard to get through to people because it is touted on every other cooking/baking website you visit!

    Keep the good info flowing…

  3. Vreni said,

    September 18, 2011 @ 1:01 pm

    Absolutely, Lisa Marie! I do think extra virgin is important for olive oil, and even though I suggest it can be heated at low temperatures, I’m thinking it is best used cold.

  4. LInda said,

    September 18, 2011 @ 9:17 pm

    I’d be interested in your thoughts on grapeseed oil. I haven’t done much homework on it but someone I trust has told me it has some extra special properties!

  5. Vreni said,

    September 18, 2011 @ 11:18 pm

    Hi Linda,

    It is also a polyunsaturated plant oil, so I personally would not consume it. The easiest way to tell if a fat is healthy is to ask yourself how easy it is to get the oil out of the plant by squishing it. Does it make a greasy mess on your fingers? If so, it is fine to eat. Getting oil out of a grapeseed would be next to impossible, so you know there is an industrial process involved. I hope that helps.

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