heating cooking oils

[Q.]

Okay, I don't have facts on this but I seem to remember that trans fats are created by heating oils. I just finished pan frying my fresh spinach, garlic, onion and pre-cooked turkey bacon (MMMMMMMMMMM!!!) in olive oil and it caused me to wonder at what point heating cooking oils might cause them to become unhealthy...?

[cward76]

I have been wondering about this to. I cook most of the chicken I eat in olive oil.

I seem to remember someone saying on MH Forum that it is ok to heat the oil, but don't let it get so hot that it smokes. If the oil smoking than it is being hydronated which is how trans fat is created.

[poopy pants]

Oil and heat

Q: What's the skinny on cooking oils and heat? Does heat negatively affect certain oils? Is there one oil I should use, or am I being too anal?

A: Since there are several good books that discuss the impact of different fats on health and body composition and since I've discussed fats often before, I'll avoid a detailed discussion of fats in general and focus simply on giving you a quick overview of what heating does to fats and my answer to the age-old question: To cook or not to cook?
Heating, under both normal high-temperature household conditions (pan frying) as well as more extreme conditions (repeated deep frying and extreme laboratory conditions), affects both the characteristics and composition of dietary fat. Heating changes the chemical structure of the fat and leads to oxidation as well as the loss of some nutrients like antioxidants and essential fatty acids. These changes are relatively universal and only vary in degree (pun intended) and duration of heating.

All oils will oxidize in a big way if repeatedly heated to high temperatures for long periods of time. But even normal household frying temperatures and durations can cause partial oxidation. Some fats, however, do better than others. Saturated fats like butter and tropical fats like coconut and palm oil are the most resistant to oxidation since they're more heat stable. Olive oil (due to it's phenolic content and monounsaturated structure) is next in terms of resistance to oxidation and heat stability. Olive oil can be made more stable by the addition of antioxidants to the oil (for example, Vitamin E). And polyunsaturated fats bring up the rear as the most easily oxidized fats and the least stable.

Therefore we now have an order of "cooking safety, showing that the saturated fats were the best while olive oil and polyunsaturated fats are the worst. This means that the physio-chemical properties of the good, "healthful" oils are the worst with cooking. Therefore the picture emerging is that the "good fats" need to be unprocessed and heated in order to stay "good."

Although I hate to do this to you, there's more bad news for us to contend with. While there are big increases in lipid oxidation products with heated oils like olive and safflower, there are also measurable physiological effects as a result. Cooking with these oils also leads to increases in plasma triglycerides and LDL cholesterol (the bad kind) and decreases in HDL cholesterol (the good kind) when compared to non-heated oils (which actually do the opposite). So not only does heating affect the fat, but it affects how the body handles the fat. Strike two!

Finally, I'll give you the last piece of bad news. It's well known that pan-frying/grilling meat will typically produce mutagenic (cancer-causing) agents. However, newer data are showing that cooking with most oil actually increases the heat transfer from the pan to the meat, increasing the mutagenic activity of the food. Strike three!
So, with all of this bad news, what's a health conscious weight lifter to do? Well, I'm about to make some recommendations. Keep in mind that some of them may go against conventional thought and/or practice. But I'm not here to appease the masses. The following recommendations will optimize your use of fats for both health and physique enhancement.

Never use additional fats when pan-frying/grilling meat! If pan-frying/grilling meat, use a non-stick surface or coat the pan with a minimal amount of some sort of cooking spray. This will prevent large increases in the amount of mutagenic chemicals formed.

Never use mono- or poly-unsaturated fats when pan-frying! When pan-frying non-meat dishes, use a non-stick surface or coat the pan with a minimal amount of cooking spray. If some sort of oil must be used for this type of cooking, use a saturated fat source like butter since these types of fats are most stable. Just be careful with how often you do this since excess saturated fat intake presents a whole other host of health problems.

When baking, use saturated fats and/or olive oil only! These are best to use for oil stability reasons (but see above for saturated fat warning).
Never heat flax oil or fish oil! Oil supplements like flax oil and fish oil need to be consumed without any further processing or else their EFA content will be destroyed. Exposure to heat and light should be prevented. In addition, olive oil is best when the extra virgin type is consumed and it's consumed unheated.

Never, ever deep fry foods!

Never, ever cook with polyunsaturated fats! Corn, canola, safflower, flax, etc. oils are the least heat stable of the oils, will become highly oxidized, and will lose their EFA content with cooking.

[cward76]

Thanks for the reply Tony even though it was not what I wanted to hear. Looks like I back to baking chicken.

That really sucks, now I have to figure out how to get olive oil back in my diet without having to just out right drink the stuff.

[poopy pants]

I wouldnt' worry about it too much, I think that article is way over the top and I don't know why the fuck I posted it.

[Q.]

Originally posted by Tony Soprano:
I wouldnt' worry about it too much, I think that article is way over the top and I don't know why the fuck I posted it.

Because you're such an alarmist!


j/k, of course
After you posted that, I remembered the rest of the tidbit that I'd heard recently... it's the REUSE of the oil that made the difference... like when my grandmother used to pour the Crisco back into the can after frying up a chicken... mmmmmmm, those were the days!

[cward76]

Originally posted by Quercus:

quote:

---

Originally posted by Tony Soprano:
I wouldnt' worry about it too much, I think that article is way over the top and I don't know why the fuck I posted it.

Because you're such an alarmist!


j/k, of course
After you posted that, I remembered the rest of the tidbit that I'd heard recently... it's the REUSE of the oil that made the difference... like when my grandmother used to pour the Crisco back into the can after frying up a chicken... mmmmmmm, those were the days! [/quote]So it is ok for me to pan fry chicken and vegetables in olive oil as long as I use fresh oil?

[Q.]

I can only tell you what I do...

I do pan fry some things with canola oil - I save the olive oil for salad dressing - but I grill or broil a lot.

Like TS said, some of the prohibitions seem too over the top but, in the end, everybody has to choose what they will and won't believe. Sorry!

[poopy pants]

Moderation is the key.

[Torque]

My wife works in the food industry and recommends using small amounts of oil when cooking, then adding the high quality oils (extra virgin olive, walnut, garlic infused, etc..) at the end of the cooking process.

[Q.]

Originally posted by Torque:
My wife works in the food industry and recommends using small amounts of oil when cooking, then adding the high quality oils (extra virgin olive, walnut, garlic infused, etc..) at the end of the cooking process.

COOL! Thanks for that info!

[Johnka]

Monounsaturated fat(like olive oil) is fairly resistant to heat oxidation. So I use it to pan fry with medium heat, particularly the spray kind. I save the good stuff (extra virgin) for drizzling over my cooked food.

My rule of thumb is to not let the oil smoke when cooking.

I think Berardi was being a little cautious in that q&a article you posted TS...he probably just didn't want people going out and deep frying with the stuff. In fact, in his most recent article he admits to pan frying with olive oil:

100% extra virgin olive oil is used in my salads and for pan-frying my egg white omelets. While the bottled form will definitely suffice, you might also want to pick up a spray can as well (also in 100% extra virgin olive oil), as it does make cooking with oil more convenient

http://www.t-nation.com/findArticle....le=04-006-diet

[kreeschtofer]

hey, what about toasting almonds (cooking them at 350* for 10 mins)??

[Johnka]

Originally posted by kreeschtofer:
hey, what about toasting almonds (cooking them at 350* for 10 mins)??

This should be fine. The fat in almonds is mostly monounsaturated, which shouldn't be damaged for such a short period in the oven.