Haidut's Summary Of PUFA

[kaybb]

A

 

[Drareg]

I am having trouble deciphering this passage. Could you clarify?

I'm with you on (1). Ideas about the universe are right or wrong.

I think I agree with you on (2), but find your language puzzling. I would replace the rainbow of uncertainty with shades of grey (to follow the black and white metaphor) and apply it to all human ideas. There is no black or white when it comes to human (un)certainty, but there are shades of grey that get pretty damn close. Are you using the colour metaphor to emphasis the broad range of uncertainty because using grey can cause people to wrongly deduce that all uncertainties are the same? Or is there some other reason?

Isn't black and white essentially the same,one does not exist without the other,both are coming form the same source,duality of sort? Essentially they are in actuality part of the rainbow or grey area however way you wish to construe it all.


@kaybb im more interested in the light than the man at the moment,it seems overpriced,I think it's plausible that this will have competition soon and prices come down fast.

In relation to using it I think it will speed up metabolism,Peat mentions this about incandescent red light so with a more coherent source it might speed up potently requiring a lot more nutrition, I think I'm good with regular sunlight for now.
I would however like to experiment so I'm tempted.

 

[jaa]

Isn't black and white essentially the same,one does not exist without the other,both are coming form the same source,duality of sort? Essentially they are in actuality part of the rainbow or grey area however way you wish to construe it all.

Not really. Black and white are not the same, though you can't have one without the other so you're right about the duality.

Black is the absence of light. White is the sum of all light. Neither exist in a rainbow.

In our analogy, black = untruth/non-reality and white = truth/reality which correlate to probabilities of 0 and 1 respectively. Humans can never assign those probabilities to their certainty of truth statements.

You can assign any probabilities to a shade of grey or shade of visible light spectrum. I think grey works better as an analogy between extremes of black and white, because near 0 probability you have black looking shades of grey, near 50% you have grey, and near 100% you have while looking shades of grey. I don't think it's as easy to intuit a colour system between those extremes, though it's easier to get across that not all probabilities are the same.

 

[Drareg]

Not really. Black and white are not the same, though you can't have one without the other so you're right about the duality.

Black is the absence of light. White is the sum of all light. Neither exist in a rainbow.

In our analogy, black = untruth/non-reality and white = truth/reality which correlate to probabilities of 0 and 1 respectively. Humans can never assign those probabilities to their certainty of truth statements.

You can assign any probabilities to a shade of grey or shade of visible light spectrum. I think grey works better as an analogy between extremes of black and white, because near 0 probability you have black looking shades of grey, near 50% you have grey, and near 100% you have while looking shades of grey. I don't think it's as easy to intuit a colour system between those extremes, though it's easier to get across that not all probabilities are the same.

I get what your saying,the light is white,the origin of everything,holomovemnet if your that way inclined.
I think we can't see this light because it's essentially absolute symmetry,humans can only see/sense broken symmetry I think ,so white the colour will be similar to black in this instance as we see both.
Anything we see is ultimately a coloured area,broken symmetry from the source of sort.

Your right though it's just an analogy of an incomplete picture so why leave others create the paradigm of what is grey,black or white.

 

[jaa]

I get what your saying,the light is white,the origin of everything,holomovemnet if your that way inclined.
I think we can't see this light because it's essentially absolute symmetry,humans can only see/sense broken symmetry I think ,so white the colour will be similar to black in this instance as we see both.
Anything we see is ultimately a coloured area,broken symmetry from the source of sort.

Your right though it's just an analogy of an incomplete picture so why leave others create the paradigm of what is grey,black or white.

I don't follow.

This discussion was about certainties and the space in-between. Things being black or white is a common phrase people use to refer to untrue or true. It's impossible for a human to have that level of certainty.

Uncertainty as shades of grey is also a common analogy and exists between black and white. This is the realm in which human certainty resides. I've never heard of an analogy that uses colours of the rainbow to denote uncertainty and it doesn't seem to match as well. This leads me to think I may be missing something in what tyw wrote.

Or maybe you're talking about something else entirely. I'm only grey level certain about what you're talking about.

 

[Drareg]

I don't follow.

This discussion was about certainties and the space in-between. Things being black or white is a common phrase people use to refer to untrue or true. It's impossible for a human to have that level of certainty.

Uncertainty as shades of grey is also a common analogy and exists between black and white. This is the realm in which human certainty resides. I've never heard of an analogy that uses colours of the rainbow to denote uncertainty and it doesn't seem to match as well. This leads me to think I may be missing something in what tyw wrote.

Or maybe you're talking about something else entirely. I'm only grey level certain about what you're talking about.

I'm agreeing with you,the phrase black and white is a necessary tool but always clouded until we understand the workings of nature,if we say we do understand nature and its infinite creativity of ideas etc then we see anything can be put forward and work.

I think its possible to create a rainbow with different colours,grey for example,the human eye is decoding the rainbow that way.
Colors

 

[chrismeyers]

You know the thread is lost when the last page is all over analysis of a metaphor someone used :-P

 

[jaa]

I'm agreeing with you,the phrase black and white is a necessary tool but always clouded until we understand the workings of nature,if we say we do understand nature and its infinite creativity of ideas etc then we see anything can be put forward and work.

I'm saying it's always clouded period. We can never be absolutely certain of anything. But we can be pretty damn close.

I think its possible to create a rainbow with different colours,grey for example,the human eye is decoding the rainbow that way.
Colors

Sure, you can use different colours of the visual spectrum to denote different levels of certainty, but that's needlessly complicated (umm, was blue the 20% certainty or 80%??) and doesn't jive with the existing known analogy of grey.

We could also use the periodic table of elements to denote certainty, or dog breeds, or anything else really, but some analogies make more sense than others.

 

[Drareg]

I'm saying it's always clouded period. We can never be absolutely certain of anything. But we can be pretty damn close.



Sure, you can use different colours of the visual spectrum to denote different levels of certainty, but that's needlessly complicated (umm, was blue the 20% certainty or 80%??) and doesn't jive with the existing known analogy of grey.

We could also use the periodic table of elements to denote certainty, or dog breeds, or anything else really, but some analogies make more sense than others.

The potential may be there though for absolute certainty in relation to the human world ,can we follow the pattern with our current limited brain/consciousness I don't know,it would have to advance. The Fibonacci ssequence is involved close to the beginning of what seems like fractal repetivness of an underlying simple Fibonacci ratio.
The complexity is coming form an ever repeating pattern it seem,trying to understand this may help more.

 

[jaa]

The potential may be there though for absolute certainty in relation to the human world ,can we follow the pattern with our current limited brain/consciousness I don't know,it would have to advance. The Fibonacci ssequence is involved close to the beginning of what seems like fractal repetivness of an underlying simple Fibonacci ratio.
The complexity is coming form an ever repeating pattern it seem,trying to understand this may help more.

There is nothing a human can do to know anything with 100% certainty, let alone identify an underlying pattern in the universe with 100% certainty.

 

[amethyst]

I've been on an ultra low fat (probably under 5 grams a day) diet for a year. I drink a gallon of fat free (skim) milk and a whole bunch of frozen fruit mashed up in it with my Nutribullet. Thats it. And I am healthier than Ive ever been. Now I assume skim milk does have some trace fat. I want to say 0.1 grams per cup. I drink 16 cups, so about 2 grams total fat. And by the way I simply dont crave fats at all anymore. Like none. I absolutely crave sugar. Both milk sugar and fruit sugar. Humans simply don't need dietary fat, PUFA or non PUFA. Thats what Ive learned over the past year and how well this has worked for me. All fats necessary can be created by your body using glucose.

Just trying to compare notes:
My question for you would be, do you get hungry being so very low fat? How much sugar are you eating, and if you are eating a lot of sugar, is that making up for the satiation factor (for you) that more fats would otherwise provide?
Inquiring minds would like to know

Me personally, I am toying with the idea of doing more starches as opposed to sugar. Maybe. I cannot make myself eat a lot of sugar (compared to others on this forum) as hard as I try. More fruit sugar from fruit, than just sugar. I also can't do super high amounts of fats. I am kind of in the middle with how much to favor...I'm kind of doing some fats and some sugar and some carbs. I've actually lost a couple of pounds, and would like to lose a few more. So maybe I'm doing ok? I know I get hungry if I go too low in fats. However, I also know if I over-exercise, I get too hungry, so perhaps less exercise will compensate, and I wouldn't be as hungry.
* The only really common variable for me Peaty-wise, is NO PUFA's. I'm really trying to eradicate outside sources of PUFA's, and if I take them in, just get them from inherent sources like chicken. Things like that.

 

[paymanz]

@tyw we should bring some factors like dopamine ,serotonin's into equation , I know you have more insight into them than me but you don't use them that much.

I know you not into restricting PUFA like Dr peat.

You said net energy intake is important to keep PUFA away from cells.

But what make someone eat too much?

Dopamine increase energy expenditure, also decreases food intake.

Serotonin lower energy expenditure.

Highr intake of Vitamin A,D , calcium linked to lower body weight.

I seen a study shows biotin lowers food intake.

Glycine and taurine shown to inhibit gaining fat and going diabetes.

So there is lot of these stuff,it can't be simplified only to energy intake.

+ such simplifying is what Atkins do.

Fat and carbs are not equal, when you limit carbs you need to break down your tissues,cortisol..

 

[tyw]

@tyw we should bring some factors like dopamine ,serotonin's into equation , I know you have more insight into them than me but you don't use them that much.

I know you not into restricting PUFA like Dr peat.

You said net energy intake is important to keep PUFA away from cells.

But what make someone eat too much?

Dopamine increase energy expenditure, also decreases food intake.

Serotonin lower energy expenditure.

Highr intake of Vitamin A,D , calcium linked to lower body weight.

I seen a study shows biotin lowers food intake.

Glycine and taurine shown to inhibit gaining fat and going diabetes.

So there is lot of these stuff,it can't be simplified only to energy intake.

+ such simplifying is what Atkins do.

Fat and carbs are not equal, when you limit carbs you need to break down your tissues,cortisol..

I don't talk about Dopamine and Serotonin because:

(a) People have already talked about them ad nausem

(b) Those already-discussed mechanical effects are accurate, but they are not base level drivers of anything. They are signalling agents, nothing more. The real question is what is driving those signalling agents to be out of whack

The claims of Energy Expenditure being important were directly pertaining to net Fat balance in the body, and net PUFA balance in the body. People cannot read this to mean "energy balance is all that matters". It is a simple fact that if fat flux is positive (excess energy, more storage), then mobilising stored PUFAs becomes very unlikely.

Then, all the mechanisms you describe are either not significant, or have such high variance that they become useless in real world practice.

- What does "High" values of Vit A, Vit D, Calcium (and I would add Vit K) even mean? I've cited Chris Masterjohn's vitamin D podcast before, and that goes to show just how complicated the issue is. "Normal" for some people is "Low" for others, and "More than Normal" is always harmful.

- Biotin is useful if the person is deficient (meaning that enzymatic complexes dependent on biotin do not have enough of if), AND that biotin can actually be used in said enzymes. There are so many factors that would get in the way of this, that it is not going to be a simple 1-to-1 relationship.

- Taurine again, only if mitochondria are deficient (and then the real question should be "why is my endogenous taurine synthesis compromised?")

- Dopamine, yeah we can take direct dopaminergic drugs, or indirect supporters of upwards pressure on dopamine homeostasis (such as nicotine), but now we have pushed the body out of balance, and it can and will fight back.

Note: there are cases of signalling compounds without negative feedback, but most are bound by tight regulatory loops. Dopamine is one of those, and anything exogenous method of spiking this signalling compound will have consequences.​

Even if you believe Peat's simple method of "More Gut Flora => more serotonin", the problem isn't the serotonin, it's the excess gut flora.

I am more concerned about root causes of imbalance, and not the resultant noise in higher level signalling mechanics. Most of the time, that signalling is just a panic-driven noisy reaction by the body, and is not very useful for diagnosis.

This still doesn't change the fact that body composition will have a large impact on PUFA mechanics, which was the original topic in the first place.

-----

Also, who ever said that I was "not into restricting PUFA"?

If you read what I've said in the past, it is very clear that I have stated that:

(a) Some level of PUFA is essential

(b) I am in general in favour of endogenous PUFA formation, to obtain the body's endogenously decided minima for PUFA concentrations in tissues.

(c) For Some people, (b) is not possible due to genetic inefficiencies in desaturase activity. They will need to get some extra PUFA from the diet.

(c1) This is still a very small amount of PUFA relative to our ability to consume it in the modern world ..... even if we talk about "1g linolenic acid a day", that's like 2 chicken eggs at most. This is far far less than the crazy PUFA consumption we see in the modern world.

.....

 

[paymanz]

@tyw
I mentioned biotin as a example of how a nutrient can effect food intake.

And it can be beneficial not only in deficiency, just look at trials on MS and Parkinson's (thiamine) they to much higher than curing a deficiency and it works.
Maybe it works because it become more available and pushes some processes in body I don't know,but I think it shows there shouldn't be necessarily a defiency to except biotin - for example - to work.

Maybe they correct those "root causes" you mentioned.

However areas you focused are very interesting and I'm thankful that you share with us.

-----
For vitamins A,D and calcium I just saw some studies showing they are linked to lower body weight.
----

I just meant to say your not as restrict as peat in regard of PUFAs.

----

And you think our endogenous taurine production can be enough to provide optimal levels?

How much do you think we need and how much we can make?

I know rats and dogs are much better than us.

We excrete about 150mg a day while a small dog is around 1g a day.

So I thought we can't be good at this anyway!

 

[kaybb]

Isn't black and white essentially the same,one does not exist without the other,both are coming form the same source,duality of sort? Essentially they are in actuality part of the rainbow or grey area however way you wish to construe it all.


@kaybb im more interested in the light than the man at the moment,it seems overpriced,I think it's plausible that this will have competition soon and prices come down fast.

In relation to using it I think it will speed up metabolism,Peat mentions this about incandescent red light so with a more coherent source it might speed up potently requiring a lot more nutrition, I think I'm good with regular sunlight for now.
I would however like to experiment so I'm tempted.

Thank you for your response. I agree...the expense! Wow. More sunlight, - good idea.

 

[tca300]

@tyw I asked Ray about calorie restriction a while back in regards to increasing longevity.

" I’ve occasionally mentioned that the typical calorie restricted diet increases the metabolic rate and decreases oxidative damage by reducing PUFA, cysteine, methionine, tryptophan, and iron, possibly some random toxins. In one of the big nurses studies, someone noticed that those who ate the most lived the longest, i.e., had the highest metabolic rate."

I know were not rodents but this shows calorie restriction shortens lifespan. http://www.abc.net.au/news/2014-03-05/low-carb-diet-may-shorten-your-life-study-finds/5299284

Just because bats can raise and lower their body temp based on environmental emperature doesnt mean they dont have on average an extremely high metabolic rate.
https://www.google.com/url?sa=t&sou...BIyEvQykfr60h0UEw&sig2=KEVu7XTrYDZ94Ujw55ANVA

Taking an animal with a very high metabolic rate and feeding it PUFA isnt going to lower its metabolism because the creature will burn through the PUFA before it can do any damage. With a human of a lesser metabolic rate, avoiding PUFA is crucial because it will accumulate with age and will regularly get dumped into the bloodstream without being burned off quickly as energy, and therefore cause damage. Im surprised someone with your opposing viewpoints would post on a website that is there specifically to discuss Rays ideas in regards to health etc...

 

[tyw]

@tyw I asked Ray about calorie restriction a while back in regards to increasing longevity.

" I’ve occasionally mentioned that the typical calorie restricted diet increases the metabolic rate and decreases oxidative damage by reducing PUFA, cysteine, methionine, tryptophan, and iron, possibly some random toxins. In one of the big nurses studies, someone noticed that those who ate the most lived the longest, i.e., had the highest metabolic rate."

I know were not rodents but this shows calorie restriction shortens lifespan. http://www.abc.net.au/news/2014-03-05/low-carb-diet-may-shorten-your-life-study-finds/5299284

Just because bats can raise and lower their body temp based on environmental emperature doesnt mean they dont have on average an extremely high metabolic rate.
https://www.google.com/url?sa=t&sou...BIyEvQykfr60h0UEw&sig2=KEVu7XTrYDZ94Ujw55ANVA

Taking an animal with a very high metabolic rate and feeding it PUFA isnt going to lower its metabolism because the creature will burn through the PUFA before it can do any damage. With a human of a lesser metabolic rate, avoiding PUFA is crucial because it will accumulate with age and will regularly get dumped into the bloodstream without being burned off quickly as energy, and therefore cause damage. Im surprised someone with your opposing viewpoints would post on a website that is there specifically to discuss Rays ideas in regards to health etc...

I think I made it very clear in the post just above that excess PUFA is obviously bad, but that we obviously need some. Cardiolipin consists of PUFAs, the brain needs some level of PUFAs. You either make these PUFAs yourself, or eat them and store them away for later use.

The point regarding bats was clear -- averages don't describe why bats function the way they do. Averages don't really matter. The ability to modulate between very high and very low metabolism is what makes these animals unique. It is this flexibility that makes it such that bats will do completely fine with both high activity (more common during summer months), yet still be fine being largely in semi-hibernation when it is unseasonal (winter) to be flying around all the time.

Matching energy production to demand, while minimising waste products, is what these animals do best. Efficiency.

It is also clear that these animals use PUFAs selectively for specific function.

eg: Hummingbirds specifically concentrate a lot of PUFA in their flight muscles in order to achieve that sort of beat frequency. Rats put what would be excessive amounts of PUFAs on their mitochondria in order to obtain faster metabolisms (at the cost of more peroxidation). I have echoed the point by Dave Valentine that "PUFAs uncontrollably speed things up".
​

This can be conditionally useful, as seen in hummingbird muscles (also in rattlesnakes). Therefore, it is not a simple question of "fast metabolism => PUFAs get oxidised". It is very clear that different organisms decide where to put PUFA and how much PUFA to put there, based on mechanisms that we largely have no understand of.

Calorie restriction has mixed results in the animal world. I do not think it is useful for humans.

....

 

[tca300]

I think I made it very clear in the post just above that excess PUFA is obviously bad, but that we obviously need some. Cardiolipin consists of PUFAs, the brain needs some level of PUFAs. You either make these PUFAs yourself, or eat them and store them away for later use.

The point regarding bats was clear -- averages don't describe why bats function the way they do. Averages don't really matter. The ability to modulate between very high and very low metabolism is what makes these animals unique. It is this flexibility that makes it such that bats will do completely fine with both high activity (more common during summer months), yet still be fine being largely in semi-hibernation when it is unseasonal (winter) to be flying around all the time.

Matching energy production to demand, while minimising waste products, is what these animals do best. Efficiency.

It is also clear that these animals use PUFAs selectively for specific function.

eg: Hummingbirds specifically concentrate a lot of PUFA in their flight muscles in order to achieve that sort of beat frequency. Rats put what would be excessive amounts of PUFAs on their mitochondria in order to obtain faster metabolisms (at the cost of more peroxidation). I have echoed the point by Dave Valentine that "PUFAs uncontrollably speed things up".
​

This can be conditionally useful, as seen in hummingbird muscles (also in rattlesnakes). Therefore, it is not a simple question of "fast metabolism => PUFAs get oxidised". It is very clear that different organisms decide where to put PUFA and how much PUFA to put there, based on mechanisms that we largely have no understand of.

Calorie restriction has mixed results in the animal world. I do not think it is useful for humans.

....

I'm assuming your looking at cardiolipin of an aged human? At birth cardiolipin is composed of palmitic acid and progressively becomes unsaturated as the human eats unsaturated fats. There have been 100's of experaments showing that PUFA's are not essential, and that animals eating diets completely devoid of them are extremely healthy and resistant to stresses ( provided micronutrient needs are met )
Perhaps different organisms store pufa in different areas simply because that is the safest place for them to be stored and quickest place for it to be burned off as energy when its released from storage, for example the hummingbirds wings, which flap at about 70 times per second would be a good ( safe ) candidate for burning pufa up quickly, vs using it as fuel for the heart which beats over 1000 times per minute and even though it uses a lot of fuel proportionally, would be damaged by the PUFA.

 

[tyw]

I'm assuming your looking at cardiolipin of an aged human? At birth cardiolipin is composed of palmitic acid and progressively becomes unsaturated as the human eats unsaturated fats. There have been 100's of experaments showing that PUFA's are not essential, and that animals eating diets completely devoid of them are extremely healthy and resistant to stresses ( provided micronutrient needs are met )
Perhaps different organisms store pufa in different areas simply because that is the safest place for them to be stored and quickest place for it to be burned off as energy when its released from storage, for example the hummingbirds wings, which flap at about 70 times per second would be a good ( safe ) candidate for burning pufa up quickly, vs using it as fuel for the heart which beats over 1000 times per minute and even though it uses a lot of fuel proportionally, would be damaged by the PUFA.

Late to reply

And no, cardiolipin with 4 units of linoleic acid (18:2) is the most common form of cardiolipin in the human body. It is particularly concentrated in the heart.

The proof that 18:2 is absolutely necessary in a healthy human heart is found by examining the case of Barth's Syndrome, which is a genetic disorder that causes Heart Cardiolipin to be altered -- Barth syndrome - Wikipedia

Studies like this show the alteration, in which there is a loss of cardiolipin with 18:2, in favour of cardiolipin with 18:1 -- Bloodspot Assay Using HPLC–Tandem Mass Spectrometry for Detection of Barth Syndrome | Clinical Chemistry

The result are all the diseases of the heart and subsequent functionality in the humans born with this defect, which is very much fatal.

Dave Valentine (author of 'Human Longevity') has this to say:

The major molecular species of CL in cardiac cells is (18:2)4-CL, in which linoleic acid (18:2) occupies all four acyl positions. In Barth’s syndrome the trend is that the 18:2 chains are replaced with more saturated fatty acids, including 18:1.

Studies of Barth’s syndrome establish the essential role of cardiolipin in energy transduction in human mitochondria. CL is primarily located in the inner membrane but is distributed in both leaflets

The universality, localization, amounts, and structure of CL suggest multiple beneficial roles, including formation of supramolecular complexes enhancing energy efficiency as well as appropriate membrane motion and permeability.

These benefits are balanced against risks associated with membrane integrity and oxidative stability.
​

The risks that are mentioned are very clear -- Influence of cardiolipin remodeling on mitochondrial respiratory function in the heart

That last study shows that excess Delta-6 desaturase activity, presumably causing more unsaturated fatty acids in the heart, is directly harmful. That is, once you get cardiolipin that is unsaturated beyond the 2 double bonds in 18:2, peroxidative stress outweighs any benefit of better energetics.

This is very clearly a case of the body having to balance the fast and furious needs of a very active tissue like the Heart, while trying to minimise the downsides. It is clear that without these PUFA on cardiolipin, the heart fails to function, and it is clear that more than the required unsaturation causes damage over time.

Balance is key.

-----

We see the same with other animals (quotes inline):

- Running Speed in Mammals Increases with Muscle n-6 Polyunsaturated Fatty Acid Content

it has been shown that experimentally n-6 PUFA-enriched diets increase the maximum swimming speed in salmon.

the proportion of PUFAs in the muscle phospholipids of an extremely fast runner, the brown hare (Lepus europaeus), are very high compared to other mammals

We found that there is indeed a general positive, surprisingly strong relation between the n-6 PUFAs content in muscle phospholipids and maximum running speed of mammals.​

- Fatty acid composition of pectoralis muscle membrane, intramuscular fat stores and adipose tissue of migrant and wintering white-throated sparrows (Zonotrichia albicollis) | Journal of Experimental Biology

During migratory seasons there was an increase in the n-6:n-3 ratio of muscle membrane phospholipid fatty acids without a change in the proportion of unsaturated fatty acids. This change was driven mainly by an increase in the proportion of 18:2n-6 and a decrease in the proportion of 22:6n-3. An increase in the proportion of 18:2n-6 was also observed in the intramuscular and adipose tissue triglyceride stores during the migratory seasons

These increases in 18:2n-6 were offset by a decrease in 16:0; resulting in an elevated proportion of unsaturated fatty acids and elevated double bond index in both fat stores of migrants

Previous studies on mitochondrial membrane composition report high levels of n-6 PUFA that were associated with an increased oxidative capacity of mitochondria (Guderley et al., 2005). However, a recent study by Maillet and Weber (Maillet and Weber, 2007) found a positive correlation between increased citrate synthase activity (a measure of mitochondrial activity) and high levels of n-3 PUFA in muscle membrane PL in migrating shorebirds.
​

- Performance-enhancing role of dietary fatty acids in a long-distance migrant shorebird: the semipalmated sandpiper | Journal of Experimental Biology

Birds were collected at various stages of fat loading to examine changes in the composition of tissue PL (membranes) and NL (fuel stores). Results show that dietary n-3 PUFA are incorporated in tissue lipids in less than 2 weeks. During the stopover, the double bond index of muscle PL increases by 25% and the fatty acid profiles of both muscle PL and adipose NL converge with that of the die

This study shows that long-distance migrant birds can (1) use natural diets rich in specific lipids to prime flight muscles for endurance exercise, and (2) modify dietary fatty acids before storing them as fuel.

In addition to membrane-related effects, EPA and DHA are also known to trigger mitochondrial and peroxisomal proliferation (Froyland et al., 1997; Jump, 2002a; Jump, 2002b; Totland et al., 2000;Yamazaki et al., 1987), and to increase the activities of key Krebs Cycle and β-oxidation enzymes (Froyland et al., 1997; Guo et al., 2005; Jump and Clarke, 1999; Sanz et al., 2000; Yamazaki et al., 1987).

This study shows that massive consumption of n-3 PUFA causes a rapid increase in the unsaturation levels of muscle PL and adipose tissue NL. However, a significant fraction of the dietary n-3 PUFA consumed is modified before storage to maintain high MUFA levels in the fuel reserves used for migration.

(TYW note: see section 'Flight muscle membranes are modified' for the context of this quote) It is therefore premature to determine whether n-3 or n-6 PUFA are most beneficial, or to generalize to all animals.

In this study, we show that semipalmated sandpipers modify their muscle membranes by feeding on Corophium as they prepare for long-distance flight.​

We can go on, but it is very clear that specific species decide to incorporate specific PUFAs on specific tisue membranes, in order to maximise raw energetic performance in those tissues. It is clear that these PUFAs are not just meant as fuel, but are specifically incorporated into membranes where they are not the targets of Mitochondrial oxidation, and are instead used for the functional purpose of "increasing rate of action" in those cells.

This comes with tradeoffs, and it is clear that each species is designed to work their tradeoffs based on species-specific needs.

This is also why I have said that when comparing any the way any other species uses PUFAs to the way that Humans use PUFAs has very little utility.

The only thing that we can discuss as a cross-species mechanism are the very-low-level mechanisms that PUFAs have at the eukaryotic and mitochondrial membrane level.

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I stand by my comments in my post above, and will say that in Humans, some level of PUFA is necessary, and that it should be endogenously regulated as much as possible.

IMO, this applies to all PUFAs, and the more unsaturated the PUFA, the more you want endogenous regulation (which was the entire point I tried to make in my DHA article).

Practically speaking, this still means that one should try to avoid any significant sources of dietary PUFA, since these fatty acids are very readily available in almost any whole food. But neither would I worry about being militant about reducing PUFA to zero.

.....

 

[arien]

@tyw @haidut
Per @tca300, highly stress resistant animals have been bred in EFAD environments. If their cardiolipin contains PUFA, it must be Mead acid. Do you believe that Mead acid is inappropriate for the formation of cardiolipin, if indeed it is always necessary for cardiolipin to contain unsaturated lipids?

I think a bio-energetic explanation of tissue specific polyunsaturation is less mystical. Those tissues which tend to accumulate more PUFA, probably have more PUFA laden blood pumped into them during stress. The stress will produce fatigue, amplified by PUFA, from which highly active tissues are unlikely to fully recover. The fatigue produced and the time necessary to recover from it will tend to increase as an organism accumulates PUFA in fat stores. By the same mechanism by which global aging proceeds, more highly active tissues will hereby locally age. The consequent tendency to partial freezing (the partial rigor mortis of ATP depletion) of the tissues probably induces the incorporation of PUFA in structural components in order to produce an excitatory melting effect, much as such fats do in organisms which metabolise at lower temperatures, such as salmon or plant seeds. Just as plants need PUFA to produce excitatory activity at low temperatures, so might fatigued muscles. I would like to be more differentiated than a plant however, and therefore try to avoid fatiguing activities.

Barth syndrome involves much more than cardiolipin unsaturation, including global lack of cardiolipin, which is found in many of the PUFA-mediated degenerative disorders, and therefore does not seem to be a conclusive case that linoleic acid is necessary for cardiolipin to function correctly. In fact, this paper (Influence of cardiolipin remodeling on mitochondrial respiratory function in the heart) which you cite concludes with:

"Unexpectedly, we also found evidence for impaired assembly of mitochondrial proteins and strikingly, reduced synthesis and/or utilization of CoA, which may reflect direct or compensatory effects of altered cardiolipin metabolism on mitochondria. This suggests that perhaps it is impairment of the
tafazzin-mediated CL remodeling process itself, not the resulting change in cardiolipin composition, which causes the mitochondrial respiratory dysfunction in Barth syndrome." (p.g. 78).