I believe the oils aren't divided this way for any taxonomic reason, but rather because we already have evidence of olive, avocado, coconut etc. oils having little-to-no impact on health, in contrast to other oils. The groups are basically "presumed innocent" oils and "presumed guilty" oils.
Or, to be more charitable, the groupings can also be looked at as "oils humans evolved eating" (olive oil, butter, coconut milk, etc) vs "oils we just started eating recently, because they can't be extracted without modern technology."
Humans did not evolve eating olive or coconut oil.
Seed oils do not require modern technology. Soybean, sesame, sunflower, etc. can be extracted with stone pressing and were extracted that way prior to any chemical extraction process. Where my family is from they’ve been eating sunflower and peanut oil for hundreds of years, milled and pressed with stone.
You are right that some cold-pressed seed oils have been used since antiquity, e.g. sesame oil.
Nevertheless, until modern extraction methods based on the use of high temperature and organic solvents have been introduced during the last two centuries such oils had remained expensive, so they were only a minor part of the food, unlike today, when if you look at the label of any kind of industrially-made food you will invariably see that some cheap oil has been added to it, e.g. soybean oil, canola oil or palm oil.
Even today, if you choose vegetable oils extracted by good methods, i.e. by cold pressing or with supercritical carbon dioxide, they are much more expensive than standard oils. For instance, the price range for cold-pressed sunflower oil overlaps with that of the cheaper kinds of extra-virgin olive oil and the prices are several times higher than for standard sunflower oil.
I have read all the 4 parts of this "Death by Vegetable Oil" series of posts.
Some of its conclusions are likely to be true, but the title is extremely misleading. A much more appropriate title would be "Death by the Cheaper Vegetable Oils".
All the data presented in these posts about the harmful effects of some vegetable oils are not applicable to vegetable oils in general, but only to those vegetable oils that have one or more of the following characteristics:
1. A high content of linoleic acid and also a too high daily intake. The optimum daily intake of linoleic acid is unknown, but it is believed to be around 10 g/day and not much over 20 g/day. In my opinion, based on the current data, an example of a daily fat intake optimized for the fatty acid profile and vitamin E content, for a sedentary human, would be 55 mL of extra-virgin olive oil + 15 mL of cold-pressed sunflower oil + a DHA+EPA omega-3 supplement. The rest of the food should have low fat content, like in grains, vegetables, fruits or lean meat. For a higher calorie intake, only the amount of extra-virgin olive oil should be increased.
2. Extraction with high temperature and/or organic solvents. One should always prefer extra-virgin oils, cold-pressed oils or oils extracted with supercritical carbon dioxide. All such oils are very sensitive to light, so they must be stored in darkness, preferably in dark glass bottles. Avoid those sold in clear plastic bottles.
3. Vegetable oils that have been heated during cooking. All vegetable oils should be mixed with the food only after cooking it and cooling it. They should not be used for frying.
4. Vegetable oils with artificial additives, e.g. with TBHQ. Avoid these.
>In my opinion, based on the current data, an example of a daily fat intake optimized for the fatty acid profile and vitamin E content, for a sedentary human, would be 55 mL of extra-virgin olive oil + 15 mL of cold-pressed sunflower oil + a DHA+EPA omega-3 supplement.
Can you provide link to this current data? I thought sunflower oil is not good for our health.
In the last 2 years, I started replacing all my cookware with a combination of cast iron, carbon steel, and stainless steel pans. So far, the only way to cook something in all of them without making the food stick is by using oil.
So I have a dilemma: What kind of oil to use with this type of cookware if I want to cook often?
Traditionally, lard was used for this purpose, not oils. This remains one of the best choices.
Good alternatives are butter or high-oleic sunflower oil or other high-oleic refined vegetable oils, which also have a low content of PUFA and of substances that are not triglycerides.
This is different from the case when the purpose of an oil is to be eaten without being heated, when cold-pressed non-refined oils are preferable, because they include various beneficial nutrients.
In any case, even if some kind of fat is used for frying, it is good to try to avoid eating most of it.
It is also possible to never use frying. In this case everything that is neither boiled nor steamed can be baked in an oven. This includes all kinds of meat (which must be cut into slices or small pieces before baking).
Home cooking is generally going to be better than particularly fast food because you are not reheating the same oils over and over.
Coconut oil is generally held as better. Cold pressed oils otherwise. Prepare to pay more for them. Be aware that food packaging labels have been known to lie about oil origin. Basically, fewer steps between growing the food and your mouth the better.
Preparing food at home is going to reduce a lot of the processing and reprocessing that happens to commercial packaged foods. I think that's going to be a net win.
Maybe get a feel for exactly how much oil is required and keep it to a minimum.
When I was using pans with a non-sticking coating, I used very little oil.
Now switching to cast-iron or carbon-steel I noticed that the best point to cook the food is to add some oil to the pan, wait for the oil to be heated properly, and only then start adding the food. Of course, I still add very little oil (maybe 1-2 tablespoons) but compared with non-sticking pans it is yet a visible thin film.
I am currently using extra-virgin olive oil but I am not sure it is good. Now I understand that instead of focusing on "extra-virgin" label I should focus on the process used to produce the oil.
On the other hand, sharing here a bit of anxiety I am no sure what to eat:
- On one hand I could try to eat more non-processed, non-cooked food like salads, vegetables ... But the risk there is being contaminated with various pesticides. So I am a bit concerned to switch to a diet mostly based on this as it means to increase a lot the quantity of such food
- On the other hand, cooking using what people consider healthy cookware means (so far for me) using some oil which I now get should be limited
- There is also the idea of red meat being bad, but also fish having mercury or radioactive elements. Probably not all of them but after reading this kind of information, I am a bit more aware of buying fish as I don't know exactly which one can be contaminated and from what area.
- The chickens seem also be not be healthy (don't remember where I read this and I somehow suspect it is false).
So I am really a bit puzzled about what to eat.
I don't think there is an easy answer.
Probably the correct answer is to grow my own food. But that is another style of life.
If you rinse vegetables well most pesticide residue will be removed. Also, some vegetables that are peeled remove that exposure route as well.
There are studies showing some kinds of organic products are worth buying because of the reasons you mention, but others are not.
I think the more you can buy food that you trust the better. This doesn't mean growing your own, it means learning more about where your food is coming from and the chain of producing and selling it. It may mean going to smaller shops, more trips, farmers markets etc. It may just mean reading about brands etc.
I think many people are wrestling with similar questions as you; you're not alone.
Using saturated or monounsaturated fats or oils are your best bets for sauteing. You can also braise things, in some kind of liquid.
Not the use of oil to avoid sticking is the problem, but eating it after that.
Besides choosing a kind of fat that is less sensitive to temperature, as described in another answer, when possible you should try to clean the fried food of the frying oil and to throw away most of the used oil.
Or, to be more charitable, the groupings can also be looked at as "oils humans evolved eating" (olive oil, butter, coconut milk, etc) vs "oils we just started eating recently, because they can't be extracted without modern technology."