Cold Temperature Produces PUFA

[Such_Saturation]

The role of desaturases in cold-induced lipid restructuring.
http://www.ncbi.nlm.nih.gov/pubmed/12440978
We have observed a clear positional specificity in this substitution and head group preferences in carp liver membranes. We have also demonstrated changes in the activity of lipid desaturases that mediate the unsaturation response, caused by both transcriptional and post-translational mechanisms.

Thermal thresholds of lipid restructuring and delta(9)-desaturase expression in the liver of carp
http://www.ncbi.nlm.nih.gov/pubmed/10637192
An isothermal induction of delta 9-desaturase in cultured carp hepatocytes.
http://www.ncbi.nlm.nih.gov/pubmed/8765141
Supplementation of cultures with oleic acid and with polyunsaturated fatty acids did not cause any reduction in the desaturase induction.

 

[haidut]

The role of desaturases in cold-induced lipid restructuring.
http://www.ncbi.nlm.nih.gov/pubmed/12440978
We have observed a clear positional specificity in this substitution and head group preferences in carp liver membranes. We have also demonstrated changes in the activity of lipid desaturases that mediate the unsaturation response, caused by both transcriptional and post-translational mechanisms.

Thermal thresholds of lipid restructuring and delta(9)-desaturase expression in the liver of carp
http://www.ncbi.nlm.nih.gov/pubmed/10637192
An isothermal induction of delta 9-desaturase in cultured carp hepatocytes.
http://www.ncbi.nlm.nih.gov/pubmed/8765141
Supplementation of cultures with oleic acid and with polyunsaturated fatty acids did not cause any reduction in the desaturase induction.

So, prolonged cold exposure would synthesize PUFA de-novo from saturated fat stores? In other words, being PUFA deficient will not protect from PUFA appearance if one is exposed to cold?

 

[tara]

I've been presuming the cattle round here get cold knees and tails outside in winter, and that is why the oxtail and knuckle fat can be liquid, which I guess is high PUFA. They may get a bit of supplemental grain in winter, but I think the majority is still grass-(or hay-or silage-) fed through winter too - ie a very similar diet all year round.
Peat has referred to studies showing stock having higher PUFA closer to the skin and lower PUFA wearing if jerseys.

 

[Such_Saturation]

Well, keeping warm should be easier while deficient!

 

[jaa]

I wonder how pronounced this effect is in humans (warm blooded animals with access to warm shelters year round living in a relatively low thermal conductive environment in air vs water). Very interesting (and slightly disheartening ) nonetheless.

 

[haidut]

I am still a little confused. I thought that once PUFA is depleted in a human, the only fats we can synthesize de-novo are the omega-9 PUFA, which are protective. I have not seen a study showing a human can synthesize linoleic or linolenic acid de-novo from saturated fats or omega-9 fats stored in tissues. If this is true then cold exposure should not be an issue.
Am I missing something?

 

[Strongbad]

So basically we should all live somewhere along equator lines where it's all nice and warm outside all year. Nice!

 

[Such_Saturation]

I am still a little confused. I thought that once PUFA is depleted in a human, the only fats we can synthesize de-novo are the omega-9 PUFA, which are protective. I have not seen a study showing a human can synthesize linoleic or linolenic acid de-novo from saturated fats or omega-9 fats stored in tissues. If this is true then cold exposure should not be an issue.
Am I missing something?

Yes, but Mead's acid is still PUFA, is it not? Also any other PUFA in your tissues would be further desaturated in cold exposure. Some plants can turn oleic into linoleic and I think that would happen as well in cold exposure. It is a physical process. http://www.sciencedirect.com/science/ar ... 9306008064 http://www.sciencedirect.com/science/ar ... 3683900767 http://link.springer.com/article/10.100 ... 011-9587-5

 

[Gl;itch.e]

Move to the tropics and wear tracksuits?

 

[tara]

So basically we should all live somewhere along equator lines where it's all nice and warm outside all year. Nice!

As we may have evolved for.
Uppity adaptable humans just spread out over as much of the globe as we could, even if it did get a bit chilly.

 

[Such_Saturation]

Here is what Ray Peat said on the radio:

the organism using carbohydrate for energy produces saturated fats or omega-9 unsaturated fats and when we come into the world we're exposed to the fats produced by organisms living at a lower temperature generally and the colder a plant is exposed to the more unsaturated his fats are and they're a different type from what we would make ourselves and those interrupt our oxidative metabolism to the extent that we become saturated with them and that happens progressively from the time we're born into old age, generally.

 

[Such_Saturation]

Cold = Pufa

 

[jyb]

https://raypeatforum.com/forums/posts/70485/ The role of desaturases in cold-induced lipid restructuring.
http://www.ncbi.nlm.nih.gov/pubmed/12440978
We have observed a clear positional specificity in this substitution and head group preferences in carp liver membranes. We have also demonstrated changes in the activity of lipid desaturases that mediate the unsaturation response, caused by both transcriptional and post-translational mechanisms.

Thermal thresholds of lipid restructuring and delta(9)-desaturase expression in the liver of carp
http://www.ncbi.nlm.nih.gov/pubmed/10637192
An isothermal induction of delta 9-desaturase in cultured carp hepatocytes.
http://www.ncbi.nlm.nih.gov/pubmed/8765141
Supplementation of cultures with oleic acid and with polyunsaturated fatty acids did not cause any reduction in the desaturase induction.

But can we draw any conclusions for humans? Because a carp lives in extreme temperatures compared to us hypothyroid humans where saturated fats have no chance of solidifying.

 

[Such_Saturation]

I would imagine such an enzyme to be a bit more sensitive than just "solid or liquid". Just having more loose electrons in the tissue could make them more available to desaturate the fat.

 

[Hugh Johnson]

https://raypeatforum.com/forums/posts/70624/ I am still a little confused. I thought that once PUFA is depleted in a human, the only fats we can synthesize de-novo are the omega-9 PUFA, which are protective. I have not seen a study showing a human can synthesize linoleic or linolenic acid de-novo from saturated fats or omega-9 fats stored in tissues. If this is true then cold exposure should not be an issue.
Am I missing something?

They're fish. Being coldblooded they will often reach temperatures that would straight kill a human, so it makes sense for them to have ability to adapt to colder temperature. At least wikipedia says humans can't make PUFA other than Mead Acid.
https://en.wikipedia.org/wiki/Fatty_acid_desaturase

 

[haidut]

https://raypeatforum.com/forums/posts/95862/

https://raypeatforum.com/forums/posts/70624/ I am still a little confused. I thought that once PUFA is depleted in a human, the only fats we can synthesize de-novo are the omega-9 PUFA, which are protective. I have not seen a study showing a human can synthesize linoleic or linolenic acid de-novo from saturated fats or omega-9 fats stored in tissues. If this is true then cold exposure should not be an issue.
Am I missing something?

They're fish. Being coldblooded they will often reach temperatures that would straight kill a human, so it makes sense for them to have ability to adapt to colder temperature. At least wikipedia says humans can't make PUFA other than Mead Acid.
https://en.wikipedia.org/wiki/Fatty_acid_desaturase

Thank you, that was my understanding as well. Otherwise, the whole idea of avoiding dietary PUFA would be somewhat pointless if something like a 3-month winter could poison your tissues with PUFA from within.

 

[Such_Saturation]

The carp is water, you are water. I am discussing the quality of the process, not the quantity.

 

[Suikerbuik]

Haidut, we might somehow overlook things. I mean PUFA content in AIDS, cancer and other diseases is quite asymmetric compared to people consuming more or less the same diet, so I'd not be surprised if it somehow turns out to be intrinsic to their metabolism. Or could it solely be something in the beta-oxidation?

 

[tara]

Some mammals have been shown to have more unsaturated fat if they live in cold conditions than warm ones. Also in cold conditions there a studies showing fats that are more unsat closer to the skin. Does the theory say that is because they preferentially store more PUFA when it is cold, and send more of it off to the extremities, but burn more PUFAs and store more SFA when it is warm? Or how might that work?

Humans too tend to have more PUFA in subcutaneous adipose than in the fat stored around the internal vital organs. I'm not sure if these finding are only from temperate regions. How do we do this?

I don't think it invalidates dietary PUFA restriction, but it does seem to add to the reasons for keeping warm by whatever means.

 

[Such_Saturation]

It desaturates and they also have access to other creatures who desaturate it. Are we on the same page here?