[vanilla-almond]

I would be interested to know if these studies refer to low quality vegetable oils using a chemical process to extract oil. For example, in the UK, supermarkets sell cold-pressed rapeseed oil (canola oil in the US). The cold-press process is sold as making rapeseed oil as relatively healthy cooking oil.

Does cold-pressing rapeseed/canola seed turn it into a relatively healthy cooking oil (vs the expeller-pressed or chemical extraction process)?

[lambdaba]

The problem is the fats in those oils are very susceptible to oxidation and have low smoke points, they are never safe as cooking oils for this reason.

For cooking the best options outside of animal fats are olive oil and coconut oil, but of course olive oil is most versatile and better tasting imo.

[Jolter]

I don’t know where you’re getting this from. I use canola oil when pan-frying food and it stands heat better then most olive oils. The cold-pressed variety tastes like shit though (well, actually it tastes like canola which has a kale-like flavor that I find unappealing). The refined canola oil is perfect for frying.

[Reason077]

Right, I think what he's saying is that you shouldn't use cold-pressed oils for cooking/frying. Cheaper refined oils are better for this purpose. Keep the fancy cold-pressed oils for salads, dipping, drizzling, etc.

Refined olive oil does have a slightly higher smoke point than refined canola/rapeseed oil, but for most home cooking purposes it's probably within the margin of error. Something like refined sunflower oil or refined avocado oil has a higher smoke point still.

[lambdaba]

Quoting this study https://actascientific.com/ASNH/pdf/ASNH-02-0083.pdf (note: I get an error opening the PDF)

> Extra virgin olive oil (EVOO) yielded low levels of polar compounds and oxidative by-products, in contrast to the high levels of by-products generated for oils such as canola oil.

But I formed my position from many other points, the degradation in public health in the USA has tracked perfectly with the switch from animal fats to seed oils for cooking (and other uses but frying is the worse offender)

[luckman212]

Any idea where I can find that study? The link above is dead. I have been using Canola oil for frying because I thought it was a neutral tasting oil that didn't produce as many toxic compounds when exposed to high heat—vs olive oil which purportedly did produce them. Seems I've been misinformed.

[lambdaba]

Here's an article that makes the same point with a great overview of the underlying mechanisms: https://breaknutrition.com/omega-6-fatty-acids-alternative-h...

[lambdaba]

Unfortunately no, the title is " Evaluation of chemical and physical changes in different commercial oils during heating", hopefully you can find it.

[maxerickson]

It also tracks perfectly with increased calorie consumption.

So one potential explanation is that people are eating more, and then another potential explanation is that there is some as yet mysterious biological process whereby processing calories through some long extant metabolic pathways triggers changes in health.

[lambdaba]

It might be good from a culinary perspective, perhaps smoke point is irrelevant, I was thinking of what causes degradation of the fats when subjected to heat.

[cworth]

The smoke point of olive oil varies significantly from extra light to extra virgin. Extra virgin actually has a much lower smoke point than canola oil.

[throwaway_pdp09]

From memory the good stuff in olive oil is destroyed by heat (if you swallow olive oil and it's good quality, you get a distinct 'burn' at the back of your throat).

Also IME olive oil loses its interesting taste rapidly when cooked with, but others may not find that.

[bitexploder]

Give avocado oil a shot. Great smoke point, no real flavor. I am allergic to avacado somehow and the oil doesn’t bother me.

[evgen]

Most allergies are to a protein in the thing you are allergic to, and refined oils that have a high smoke point usually have all of that removed (or it would cause the oil to smoke.) I have a peanut allergy but can eat anything fried by a cheap restaurant in Sysco peanut oil while I have had a reaction to something done by a three star restaurant because they used unrefined oil (looking at you Manressa...)

[bitexploder]

Makes sense. Good to know, thanks.

[shin_lao]

Avocado oil is much better than olive oil, which has a low boiling point.

[lambdaba]

It's probably equivalent but the taste doesn't go with most foods, also it goes bad much easier which again suggests less stability.

[microcolonel]

If you're concerned about the taste of Avocado oil you may have just had poor quality oil. I've had some bad experiences, but the one from Chosen Foods (we have it at Costco in Ontario) is a very neutral oil with a high smoke point.