Oil & Lipid peroxidation

[fred]

If you are concerned about lipid peroxidation, then simply don't consume olive oil because it contains peroxides.

http://www.oliveoilsource.com/page/chem ... #Peroxides :

Peroxides are the primary products of oxidation of olive oil. Fats and oils such as olive oil are oxidized when they come in contact with oxygen. Oxygen may exist in the headspace of the container and dissolve in the oil. The oxidation products have an unpleasant flavor and odor and may adversely affect the nutritional value of the oil. Essential fatty acids such as linoleic and linolenic are destroyed, and certain fat soluble vitamins disappear. Fatty acids are oxidized by one of the following mechanisms.

Auto-oxidation occurs in the absence of air by reactive oxygen species or "free radicals". It is temporarily prevented by the natural antioxidants in the oil that absorb these free radicals. When the antioxidants are used up, the oil ages quickly.

Photo-oxidation occurs when the oil is exposed to natural and/or artificial light sources (including halogen lights and store lights). It causes serious deterioration of olive oil, as it can occur up to 30,000 times faster than auto-oxidation.

The more rancid or oxidized the oil, the more peroxides are present. Measurement of the peroxides in olive oil is a very simple procedure which can done at a testing lab or with a CDR tester. High quality extra virgin olive oils have a peroxide value of less than 10meq/kg. In order to be extra virgin, olive oil must have less than 20 meq/kg.

[RRM]

If you are concerned about lipid peroxidation, then simply don't consume olive oil because it contains peroxides.

What kind of statement is that?
Do you actually think that to decrease lipid peroxidation, it is better to consume other fats than olive oil?
Check out the WaiWiki about lipid peroxidation. http://www.waiwiki.org/index.php/Lipid_peroxidation

Fats and oils ... are oxidized when they come in contact with oxygen.

Do you think that other oils / fats do not come in contact with oxygen?

[fred]

All vegetable oils contain more or less peroxides, including olive oil, so IF YOU ARE CONCERNED ABOUT LIPID PEROXIDATION, don't consume oil.
Oil/fat when they are in food (and not extracted) is less prone to oxidation so yes it is better to eat whole food in this regard. Don't you think?

[dime]

I'd need to eat 1.5kg of olives a day then.. not so feasible.
Again, in practice this type of idealizing makes negligible difference while making your diet impossible.

[RRM]

IF YOU ARE CONCERNED ABOUT LIPID PEROXIDATION, don't consume oil. ...
it is better to eat whole food in this regard. Don't you think?

No, its not that simple.
Lipid peroxidation is a chain reaction that creates rancid fats, which is easily detected in stored foods such as oils.
(a rancid oil smells very bad)
Eating olives instead of olive oil for the fat, is unrealistic, indeed. Avocado is a better source.
Consuming other fats instead of (high oleic acid) oil creates another dilemma.
Thats because lipid peroxidation may happen during storage (and cooking), but also endogenously.
Polyunsaturated fatty acids (in animal fats) are more prone to lipid peroxidation, whereas oleic acid (in olive oil, macadamia oil, avocado oil) inhibits lipid peroxidation.
http://www.waiwiki.org/index.php/Lipid_peroxidation

[fred]

The risk of endogenous lipid peroxidation is much higher with consuming an oil that has already start to oxidize and which lack part of its antioxydants, than with consuming a whole food which contain all its antioxydants. Also, it is much easier to exceed a certain amount of PUFAS and generate non-enzymatic peroxidation with oil than with whole food.

Polyunsaturated fatty acids (in animal fats) are more prone to lipid peroxidation, whereas oleic acid (in olive oil, macadamia oil, avocado oil) inhibits lipid peroxidation.

Even with high oleic acid animal fat like in pork or duck ?
Does saturate fat help to limit lipid peroxidation ?

[RRM]

The risk of endogenous lipid peroxidation is much higher with consuming an oil that has already start to oxidize

Lipidperoxidation is a chain reaction.
This means that when lipid oxidations sets in, eventually the entire oil is rancid.
This is easily noticed.
Hence the lipidoxidation products in olive oil that is still perfectly good, must be unreactive.

Also, it is much easier to exceed a certain amount of PUFAS and generate non-enzymatic peroxidation with oil than with whole food.

Not with olive oil compared to whole animal foods.

Polyunsaturated fatty acids (in animal fats) are more prone to lipid peroxidation, whereas oleic acid (in olive oil, macadamia oil, avocado oil) inhibits lipid peroxidation.

Even with high oleic acid animal fat like in pork or duck?

Your claim was that oils such as olive oil are worse for lipid peroxidation than whole foods.
Now you are resorting to pork and duck?

Oleic acid contents in comparison:
81% macadamia oil
77% olive oil
76% avocado oil

55% goose fat
47% poultry fat
41% Lard
39% Beef-suet tallow
25% butter fat
15% herring oil

[fred]

The risk of endogenous lipid peroxidation is much higher with consuming an oil that has already start to oxidize

Lipidperoxidation is a chain reaction.
This means that when lipid oxidations sets in, eventually the entire oil is rancid.
This is easily noticed.
Hence the lipidoxidation products in olive oil that is still perfectly good, must be unreactive.

Actually the oxidation reaction starts when the oil is extracted, but it is relatively slow at the beginning, and suddenly speeds up. Hence lipid peroxidation products in olive oil are reactive and slowly increase, even if you don't notice it.

Also, it is much easier to exceed a certain amount of PUFAS and generate non-enzymatic peroxidation with oil than with whole food.

Not with olive oil compared to whole animal foods.

Not sure. Unless you choose very fatty meat of course. Anyway I was thinking of vegetable food.

Polyunsaturated fatty acids (in animal fats) are more prone to lipid peroxidation, whereas oleic acid (in olive oil, macadamia oil, avocado oil) inhibits lipid peroxidation.

Even with high oleic acid animal fat like in pork or duck?

Your claim was that oils such as olive oil are worse for lipid peroxidation than whole foods.
Now you are resorting to pork and duck?

My point is to say that an oil is prone to oxydation because it is stripped of a part of its antioxydants and exposed to oxygen and light. A whole food (vegetal or animal), is better protected from this point of view. In addition, one generally eats less oil/fat from whole food than from extracted food, hence less PUFAs is ingested which lower lipid peroxidation risks.
Oleic acid content is not the only parameter as you know!

[RRM]

IF YOU ARE CONCERNED ABOUT LIPID PEROXIDATION, don't consume oil. ...
it is better to eat whole food in this regard. Don't you think?

No, its not that simple.

Oleic acid content is not the only parameter as you know!

Thats what im trying to tell you; its not that simple.
Your initial statement: regarding lipid peroxidation, oils are worse than whole foods.
But as i have shown you, there are multiple factors at play.
Your statement is simply wrong / incorrect.
Its generalizing.
Some whole foods may be worse than some oils, regarding lipid peroxidation.
And some oils (if already oxidized, or high PUFA, or low oleic acid) may be worse than some whole foods, regarding lipid peroxidation.

Also, it is much easier to exceed a certain amount of PUFAS and generate non-enzymatic peroxidation with oil than with whole food.

Not with olive oil compared to whole animal foods.

I was thinking of vegetable food.

No, you were not.
You said oils compared to whole foods.
You even mentioned pork and duck.

an oil is prone to oxydation because it is stripped of a part of its antioxydants and exposed to oxygen and light. A whole food (vegetal or animal), is better protected from this point of view.

Again, this is not the only factor.
Yes, its true when you compare olive oil to olives, but its not true for any whole food compared to any oil.
It really depends on what food and what oil you are talking about. (as oleic acid and PUFA contents also play a role)
Therefore, your statement that oils are worse, is simply incorrect.

In addition, one generally eats less oil/fat from whole food than from extracted food

Again, this is a baseless statement. Thats pure speculation.
Let me give 2 examples.
Fish oil is not the best tasting supplement, and eating fish might be far more pleasant,
so that when eating fish with your meal instead of adding fish oil, you may end up ingesting far more fat.
Eating macadamia nuts, you may end up ingesting more fat than when adding macadamia oil to your food,
simply because it may be more appealing to eat (many) nuts.

[fred]

Actually what I wanted to say is that regarding lipid peroxidation, it is better to eat a whole food rather than the oil extracted from this same food. For instance, it is better to eat avocado than avocado oil, or olive than olive oil. I was not thinking about animal food product, but we can also say that it is better to eat salmon rather than salmon oil, etc.
But you are right, there are many factors involved and we can't compare different food.
And we agree that oil starts to oxidize right after extraction. That's enough for me to limit my oil intake.

[RRM]

Actually what I wanted to say is that regarding lipid peroxidation, it is better to eat a whole food rather than the oil extracted from this same food.

The whole purpose of taking oil, is adding fat effortlessly. (to juice, for example)
Eating a kg of olives to add fat to your diet is not an option.

And we agree that oil starts to oxidize right after extraction. That's enough for me to limit my oil intake.

Simply only consume perfect tasting oil. (and high quality, of course)
If it is not enough to give the oil a hint of a rancid taste, the peroxidation is minimal.
Lipid peroxidation is physiologically perfectly natural, in as much as the oxidative damage resulting from breathing.
As the body can cope with a certain level of endogenous lipoxidation (through various antioxidants, enzymes, such as taurine and glutathione),
it can also perfectly deal with those minimal levels in perfect tasting oil.

Dried corn for feeding pigs may have a peroxide value of 84.1 mEq/kg oil, and the mean value of such feedings may be 11.5 mEq/kg oil. Sonq R et al
Salted fish may have a peroxide value of 28.90 meq/kg after 90 days of storage at 4°C. Ali M
A cereal bar may have a peroxide value of 12 Escobar to 25.7 meq/kg. Estévez AM et al
Menhaden (a fish) oil may have a peroxide value of 5.70 meq/kg. Yin H et al
Sardine oil may have a peroxide value of less than 1 meq/kg. Tovoshima K et al
The peroxide value of omega-3 supplements may be 1.04-10.38 meq/kg, and 0.60-5.33 meq/kg for fresh vegetable oils (incl. sunflower, soybean, corn, olive). Halvorsen, BL et al
Of these vegetable oils, olive oil was most resistant to heat (due to oleic acid). Full free text
The peroxide value of various fresh oils (palms, soybean) is usually between 2 and 3 mEq/kg oil, and between 11 and 17 mEq/kg oil after frying five times. Kamisah Y et al, but palm oils may also have a peroxide value around 0.19 meq/kg. Coimbra MC et al
Seed oils of wild plants may have a peroxide value of 27.5 mEq/kg, and may increase 12-fold due to 65 days of exposure to light at ambient temperature. Eromosele IC et al

Just make sure not to expose the oil to sunlight. Sunlight exposed fresh oil may have a 'high' peroxide value of 5.8 mEq/kg,
versus unexposed 0.4 mEq/kg Laillou A et al

[Kasper]

Why do you think that the oleic acid content is the main factor regarding lipoxidation ? As far as I know, PUFA content and vitamin E content are also very important factors. Right ?

[overkees]

What about butter oil and lipid peroxidation? Coconut oil and lipid peroxidation? These are highly resistant to peroxidation. I would rather choose such a fat than something like olive oil.

You can leave a bottle of coconut oil in the sun for weeks without it starting to become rancid. Saturated fats are much more used for metabolism so they are much safer to endogenous oxidation processes than olive oil and such.

Problem is, you cannot mix them with juice.

[RRM]

Why do you think that the oleic acid content is the main factor regarding lipoxidation ?

I dont.
All I wrote was:

the similar content of oleic acid yields no benefit of one of these 3 oils over the other

So, i was solely talking about the factor oleic acid, and I did not say that "nor does any other factor".
There are MANY factors at play.
Here is a list of just inhibitors of (the effects of) lipoxidation: http://www.waiwiki.org/index.php/Lipid_ ... Inhibitors

[RRM]

What about butter oil and lipid peroxidation? Coconut oil and lipid peroxidation? These are highly resistant to peroxidation. I would rather choose such a fat than something like olive oil.

Resistance to lipoxidation is just one factor.
Butter is excluded from this diet.
Regarding fatty acid requirements, i think olive oil is better balanced than coconut oil.
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