I grew up in a foodie household, and my mom always used Mazola vegetable oil to cook with. At the time (the 70s and 80s, if you must know), there wasn’t a huge variety of oils in the supermarket, and nobody really cared about nutrition all that much. People were more like, ‘pass the cheez crackers and Tab!’ 

Now, we’re all concerned with our health and the number of different oils in the grocery store is dizzying. Add in certain diets that say that saturated fat is healthy, and the whole fats thing is even more puzzling. Is saturated fat okay now? Is olive oil dangerous? Is canola oil processed crap? 

So many questions.

Just a little primer on fats

Monounsaturated: These fats are known as the ‘good’ fats because they appear to help improve blood cholesterol levels. Oils high in monounsaturates include olive, canola, and avocado. Nut oils like walnut and hazelnut are great too, but their smoke points are super low so use these oils in salads and cold dishes.

Polyunsaturated: These include omega-3 and omega-6 fats. Diets that have a lot of omega 6 and too little omega 3 fats are thought to be inflammatory. Many of the high omega-6 oils we eat are found in ultra-processed foods. Oils high in polyunsaturates include canola, soybean, corn, and sunflower.

Saturated: The degree of unhealthiness of saturated fat is perhaps the most debated nutrition topic of this century. Some research suggests that replacing saturated fat with polyunsaturates (but not refined carbs) can lower cholesterol levels significantly (and some doesn’t).

There appears to be a correlation between a diet high in saturated fat and high cholesterol/heart disease, but I’m going to go out on a limb here and say that nobody has ever singled out saturated fat itself as the exact cause in this case. Oils high in saturated fat include coconut and palm oil. 

A lot of people ask me about coconut oil. While it’s not the nutrition miracle some people will have you believe, it doesn’t appear to be the devil, either. Don’t eat it by the spoonful. Don’t eat any oil by the spoonful, and you should be just fine.

It’s important to note that every single oil is a combination of these fats. Even the most saturated fats in the world – coconut and palm kernel oil, FYI – contain at least some unsaturated fat. By the same token, even olive oil contains saturated fat.

It’s also important to consider that different people react differently to different nutrients. Just because your boss can eat nothing but steak for three months and have their cholesterol levels drop, doesn’t mean that you’re going to have the same outcome. Our genetic makeup, gut bacteria, and possibly other factors influence how our bodies process food. This is why I become infuriated when people try to say that their diet is the ‘best’…it’s just never going to be true for everyone. 

One-size-fits-all doesn’t work in nutrition (that’s another blog post all together). 

Smoke Points

Let’s talk about smoke points, because many people have asked me if oils become harmful when they’re overheated. When an oil breaks down under heat, it produces polar compounds, which can be bad for our health. If you’re cooking with an oil, choose one with a higher smoke point (depending on how high you’re heating it and for how long).

I’ve pulled this ah-mazing chart from Diet vs Disease on smoke points and polar compounds because I couldn’t possibly improve on it. 

It’s important to note that the study that this chart is pulled from was sponsored by the olive oil people. Also, the oils in the study were heated to temps that home cooks would rarely if ever reach.

Notice that canola oil, sunflower oil, and grapeseed oils, as the graphic says, have the highest smoke points but also the highest percentage of polar compounds. The lesson: don’t overheat your oils.

Refined oils: are they harmful? 

I want to talk a bit about refined oils, because lots of people seem to be on the ‘refined oils are toxic’ train and truthfully, I didn’t know the deal. I did some research on refined oils and the refining process, and here’s what I found:

When you search ‘refined oils harmful’, all sorts of quacky sites pop up. It’s safe to say that when I see Mark Hyman, Food Babe, or Josh Axe telling people not to do something, I most certainly will recommend doing the opposite. Predictably, they and many other ‘alternative’ sites recommend staying far away from refined oils. 

Refined oils like canola, soy, corn, and palm are expelled from their sources using chemicals or a mill. They’re heated, deodorized, and sometimes bleached. The high heat used during processing may decrease antioxidant and vitamin content. Does this process end up making the oils dangerous? Should you avoid canola and other refined oils?

Eh, not really. Of course, I don’t think there’s any one food in the world that you need to avoid altogether. With oils, it comes down to how much and how often you choose them. Let’s put it this way: if you’re eating a ton of refined oil, and you’re mostly eating it in ultra-processed foods, this is a whole other issue. If you’re cooking with only refined oil, mix it up with other oils. Variety is one of the hallmarks of a healthy diet. 

There’s no reason to get paranoid because people are tweeting about the dangers of ‘seed oils’ and how toxic they are. If you’re eating a lot of seed oils, your overall diet could probably use a few tweaks. 

canola field
I took this picture of a canola field in Saskatchewan. Canola looks pretty, but it STINKS.


What Does This All Mean?

The whole oil thing is controversial, and it’s because we really don’t know how different oils affect us exactly. Nutrition studies on oils – and on anything – are notoriously difficult to do and end up being correlational at best. We can say that people who eat one type of oil are less healthy overall, but is it the oil, or their overall diet, that’s making them that way? 

Nobody eats just oil, they eat food with oil in it. Add that to the fact that we all process food differently, and you get what we’ve seen over the past few decades: flip-flopping nutrition recommendations and Twitter spats about whether saturated fats/seed oils/whatever are harmful or not.

We just don’t know for sure. 

Monounsaturated fats seem to have the most positive evidence for health. The others don’t seem to be all that horrible. Don’t eat a shitload of oil in the first place. Mix things up.

That’s about as close as we get to a definitive statement on oils.

Trans fats are the only fat we know is 1000% unhealthy. Nobody’s arguing about that one. They’re being taken out of the food supply, but again: if you’re eating a lot of trans fats, chances are you’re eating a highly processed diet. 

So which fats should you choose?

A little of everything.

As I keep saying, a healthy diet has a combination of fats (and foods!). While I still believe that the majority of your fat should be monounsaturated, using butter and coconut oil is fine. As I always say, nobody is going to have a heart attack because they use butter on their toast. 

My recommendation for overall best oil: 

In terms of health benefits, olive oil beats every other oil for antioxidants and good fats. BOOM. The funny thing is that many people believe that olive oil has a smoke point that’s too low for cooking, but in reality, pure olive oil’s smoke point is 465F (EVOO’s smoke point is around 375F). It doesn’t produce a ton of polar compounds.

Olive oil – extra virgin or regular –  is my first choice for cooking and using cold. Don’t trust anyone who says that olive oil is toxic; that’s just crazy talk.

Enjoy your food, and as with anything, use a combination of different oils. Don’t eat too much of it. That’s all.