haidut

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This is great human study that addresses two key questions people have often asked Peat in regards to SFA vs. PUFA. As Peat has mentioned several times, during stress (exercise in this case) PUFA is preferentially oxidized while SFA is stored. The preferential oxidization of PUFA during stress is likely what accounts for many of the damages caused by elevated lipolysis. I recently posted a study showing that kidney damage in diabetes is likely due to precisely such elevation in lipolysis and fatty acid (PUFA) oxidation.
Increased Fat Oxidation Is The Cause Of Kidney Damage In Diabetes

The human study below corroborates the differential metabolism and effects of PUFA/SFA, and it did so by administering an absolutely massive amount of fat - 300g of either SFA or PUFA over a period of just 5 hours. So, with this amount of fat there can be no question that whatever effects were seen were due to the fat and not some other factor. The study looked at many parameters but the only one that was significantly different between the SFA and PUFA groups was the activity of the enzyme pyruvate dehydrogenase (PDH), which is the limiting factor for glucose oxidation. As the study mentions, aside from SFA, increased availability of glucose also increases PDH activity. So, in effect, glucose promotes its own oxidation while fats have differential effects. Namely, SFA promote glucose oxidation by increasing PDH while PUFA promote fat oxidation AND also block glucose oxidation by increasing PDK (the enzyme that deactivates PDH).

The acute effects of differential dietary fatty acids on human skeletal muscle pyruvate dehydrogenase activity. - PubMed - NCBI
"...More recently, however, it has been shown that metabolically, distinct classes of fatty acids in the diet are handled differently. Chain length and degree of saturation of long-chain fatty acids appear to have an effect on the partitioning of fatty acids between oxidation and storage. Saturated fatty acids (SFAs) are more preferentially diverted to storage, whereas polyunsaturated fatty acids (PUFAs) are more preferentially oxidized, as is the case for n-6 fatty acids, or used as building blocks for plasma membranes, as is the case with n-3 fatty acids (16, 17, 30, 46)."

"...During times of high CHO availability, PDH activation is increased, increasing CHO flux into the TCA cycle. When CHO availability is low, PDH activity decreases, thus sparing CHO for use in other areas of the body (35). Both acute and chronic (or adaptive) regulation of the PDH complex occurs via two intrinsic regulatory enzymes, a family of PDH kinases (PDK1–4; inhibitory) and a pair of PDH phosphatases (PDP1 and -2; stimulatory) (14, 40). Of the four isoforms of PDK, PDK2 and PDK4 are the most abundant in skeletal muscle. The PDKs phosphorylate up to three serine residues on the E1α subunit of the PDH complex, and although site 1 is sufficient for complete inactivation of the complex, increased occupancy of sites 2 and 3 renders the complex less sensitive to activation by PDP (40). PDK4 has been shown to be most responsive to alterations in diet (12, 27, 28) and has a higher affinity for site 2 as a substrate than PDK2 (40). Research has demonstrated that only 24 h of a high-fat/low-CHO diet will increase PDK activity and consequently decrease PDH activity in human skeletal muscle (27). However, it is not yet known whether this adaptive increase in PDK activity would be observed in a shorter time period. In addition, recent studies have suggested that the type of dietary fat may influence the partitioning of fat between oxidation and storage (30, 46) and may specifically alter the magnitude of adaptive changes in the PDH complex (43)."

"...The total caloric value of the trial meals consumed over the 5 h was well matched at 2,811 kcal (SFA) and 2,947 kcal (PUFA). The SFA and PUFA diets were similar with respect to protein, CHO, total fat, and MUFA content, with the only difference being the amount of SFA (mainly 14:0, 16:0, and 18:0) and PUFA (mainly 18:2 n-6; Table 1)."

"...PDHa activity increased significantly in the first minute of exercise in the SFA trial from 1.29 ± 0.24 to 2.16 ± 0.37 mmol·min−1·kg wet wt−1 (P < 0.05), whereas there was no change in PDHa activity with exercise during the PUFA trial (Fig. 4). PDHa activity was significantly higher in SFA compared with PUFA at the onset of exercise (SFA 2.16 ± 0.37 mmol·min−1·kg wet wt−1; PUFA 1.28 ± 0.36 mmol·min−1·kg wet wt−1; P < 0.05)."

"...The primary purpose of this study was to determine whether a 5-h load of differential dietary fatty acids would have unique effects on PDK and PDHa activity at rest and at the onset of exercise. An attenuation of PDHa activity at the onset of exercise and increased fat oxidation during exercise was observed with n-6 PUFA compared with SFA."


Elevated n-3 fatty acids in a high-fat diet attenuate the increase in PDH kinase activity but not PDH activity in human skeletal muscle. - PubMed - NCBI
"...We tested the hypothesis that a high-fat diet (75% fat; 5% carbohydrates; 20% protein), for which 15% of the fat content was substituted with n-3 fatty acids, would not exhibit the diet-induced increase in pyruvate dehydrogenase kinase (PDK) activity, which is normally observed in human skeletal muscle. The fat content was the same in both the regular high-fat diet (HF) and in the n-3-substituted diet (N3). PDK activity increased after both high-fat diets, but the increase was attenuated after the N3 diet (0.051 ± 0.007 and 0.218 ± 0.047 min−1 for pre- and post-HF, respectively; vs. 0.073 ± 0.016 and 0.133 ± 0.032 min−1 for pre- and post-N3, respectively). However, the active form of pyruvate dehydrogenase (PDHa) activity decreased to a similar extent in both conditions (0.93 ± 0.17 and 0.43 ± 0.09 mmol/kg wet wt pre- and post-HF; vs. 0.87 ± 0.19 and 0.39 ± 0.05 mmol/kg wet wt pre- and post-N3, respectively)"
 

Kartoffel

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Saturated fatty acids (SFAs) are more preferentially diverted to storage, whereas polyunsaturated fatty acids (PUFAs) are more preferentially oxidized, as is the case for n-6 fatty acids, or used as building blocks for plasma membranes, as is the case with n-3 fatty acids (16, 17, 30, 46)."

Oddly, Peat keeps insisting (see the latest interview) that the body prefers storing PUFA instead of burning them. I think it's the main reason he reduced his consumption of fat by a lot. He used to eat a lot of fat but said he was afraid of PUFA accumulation, and therefore cut it down.

"I think that proportion is good for most people; I felt good while I was averaging about 50% fat, but I decided to reduce it to avoid PUFA accumulation, so now I’m trying to keep sugar over 50%, fat a lot lower." (Ray)​
 
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rei

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I think he says that fat cells preferentially use saturated fat for their energy, so pufa is stored. But pufa is what comes first out from a fat cell because it is on the surface of the fat droplet.
 

Mauritio

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Yeah I think so too he said that PUFA gets preferentially stored to protect the mitochondria . He also said that there will always be PUFA accumulation since even things like butter or coconut oil contain some PUFA . I wonder how he stands on PUFA depletion with the 30- days- no- fat-diet ?
 
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Ideonaut

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Fine. By writing "increase" and "decrease" instead of "increaseS" and "decreaseS" I suppose you save some space and time, but at the expense of sounding retarded and causing annoyance. What's wrong with correct English?
 

schultz

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Fine. By writing "increase" and "decrease" instead of "increaseS" and "decreaseS" I suppose you save some space and time, but at the expense of sounding retarded and causing annoyance. What's wrong with correct English?

Woah, what's with your rage increases?
 

michael94

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I dont think pufas cause anger, if anything it can make people inappropriately happy because of their effect on bile solubility in the short term. And even mufa rich foods or mufa/pufa mixdepending on the type. like avocadoes or olive oil.

anger maps onto iron and cholestasis for me, and not always in a bad way... coffee can make one inappropriately happy also and Im one of the worst culprits of that.
 

Hugh Johnson

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Oddly, Peat keeps insisting (see the latest interview) that the body prefers storing PUFA instead of burning them. I think it's the main reason he reduced his consumption of fat by a lot. He used to eat a lot of fat but said he was afraid of PUFA accumulation, and therefore cut it down.

"I think that proportion is good for most people; I felt good while I was averaging about 50% fat, but I decided to reduce it to avoid PUFA accumulation, so now I’m trying to keep sugar over 50%, fat a lot lower." (Ray)​
Peat has moved on to hydrogenated coconut oil, so that might be different now. Also, skeletal muscle might act differently than other muscles, as it is characterized by toughness. Bicep cancer is pretty rare, so muscle can take the hit of PUFA better than other organs.
 

Kartoffel

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Peat has moved on to hydrogenated coconut oil, so that might be different now. Also, skeletal muscle might act differently than other muscles, as it is characterized by toughness. Bicep cancer is pretty rare, so muscle can take the hit of PUFA better than other organs.

That email is just two weeks old, so I think this is what he is doing nowadays. I have been reading some studies looking at the fatty acid composition of adipose tissue, and it seems that fatty acids in fat cells more or less directly reflect what fats you eat. That is except you're a Tokelauan that eats 150 grams of coconut fat a day. In that case, PUFA content of adipose tissue will probably be even lower than the percentage of it in your diet, and you will use your Δ-9-desaturase enzymes to make a lot of monounsaturated oleic acid (18:1), and palmitoleic acid (16:1) from your own saturated fats.

upload_2019-1-30_14-54-43.png
 
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Aymen

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I,m really confused , aren't PUFA released during stress and our muscles prefers to oxidize the saturated fats and prefers to store the water soluble polyunsaturated fats ?
i just found this :

CALLER: I'm Chris from Colorado Springs, and I have two questions for Dr Peat, one's on topic and the other one's completely off topic And first I wanted to say to you Andrew that I and a lot of the listeners do miss Sarah and hope she returns but, I just want to say, you have been doing a great job doing the show by yourself, keep up the good work. Dr Peat in terms of longevity and in reading your articles, one gets the idea of the importance of saturated fats and the avoidance of the unsaturated fats. However, in terms of proper oxidative energy,and importance that sugars like sucrose and lactose play into that, how important is it maybe to keep the fats on the low side and focus on the sugars or is there still a minimum of fat and saturated fat that is important in terms of longevity?

RAY PEAT: A certain small amount of fat helps to stimulate the intestine and activate absorption of the oily vitamins - vitamins K, D, A & E. And about 30 or 40 years ago, I was looking at the association of various fats with the cancer, spontaneous cancer incidence and I saw that coconut oil had the lowest of the natural oils, but someone found that hydrogenated coconut oil containing zero polyunsaturated or 'essential' acids, had the lowest incidence of spontaneous cancer of all, essentially like a completely fat-free diet. And so, the fat... even 2 or 3% of PUFA in butter and coconut oil, the fact that that accumulates - because our muscles, for example, quickly oxidize the saturated fats and preferentially we store the more water soluble, polyunsaturated fats - and so over time even eating a moderate amount of butter and coconut oil, our tissues will become increasingly saturated with the polyunsaturated fats. And the fat cells, which store little droplets of fat, they for their own energy prefer - like the muscles - they prefer to oxidize the safe, saturated fats. So, our fat tissues with age become more and more concentrated with a relatively pure polyunsaturated store of fat. And, under stress, fat is released and especially the polyunsaturated, which is more accessible to the stress activation. So, with age, stress becomes more harmful, because you've stored up more of the PUFA. So, since we can make all of the saturated fats, palmitate, stearate and we can desaturate stearic acid to make oleic acid and our own series of polyunsaturateds, I think it's best to get as much sugar and starch in your diet, preferably sugars from fruit and milk, and minimise the exposure to the unstable and n-6 and n-3 fatty acids.
 

koky

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I wonder why in the same interview Peat said he's switched to hydrogenated coconut oil, he also said he eats some olive oil every day?
 

Cirion

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Body preferentially storing PUFA is misleading, I think, considering that people have measured adipose tissue and found that the composition is SFA >MUFA > PUFA. Most of it SFA, moderate amount MUFA, and small amount PUFA. I don't doubt that we have PUFA stored, or that its a big problem, but I don't think our body fat is mostly made of PUFA, even in unhealthy people. Though I have no doubt, the unhealthy person will have way more PUFA stored overall.

edit - just noticed the link posted above. Maybe I stand corrected after all. I based my statement upon something I remember reading in art and science of low carbohydrate performance.
 

Kartoffel

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Body preferentially storing PUFA is misleading, I think, considering that people have measured adipose tissue and found that the composition is SFA >MUFA > PUFA. Most of it SFA, moderate amount MUFA, and small amount PUFA. I don't doubt that we have PUFA stored, or that its a big problem, but I don't think our body fat is mostly made of PUFA, even in unhealthy people. Though I have no doubt, the unhealthy person will have way more PUFA stored overall.

edit - just noticed the link posted above. Maybe I stand corrected after all. I based my statement upon something I remember reading in art and science of low carbohydrate performance.

Actually, 18:1 oleic acid alone (monunsaturated) makes up about 50% in most people. So, our adipose tissues are mainly monounsaturated.
 

Hugh Johnson

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That email is just two weeks old, so I think this is what he is doing nowadays. I have been reading some studies looking at the fatty acid composition of adipose tissue, and it seems that fatty acids in fat cells more or less directly reflect what fats you eat. That is except you're a Tokelauan that eats 150 grams of coconut fat a day. In that case, PUFA content of adipose tissue will probably be even lower than the percentage of it in your diet, and you will use your Δ-9-desaturase enzymes to make a lot of monounsaturated oleic acid (18:1), and palmitoleic acid (16:1) from your own saturated fats.

View attachment 12028
Sounds reasonable. However, that study seems strange in that the NZ Europeans have next to no stored PUFA. Meanwhile American study here (Composition of adipose tissue and marrow fat in humans by 1H NMR at 7 Tesla) showed about 24% PUFA. Maybe NZ diet is really healthy, but I doubt that:

New Zealand battles obesity epidemic as third fattest country in the world
 

Cirion

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Also, what about the infamous randle cycle?

Does even PURE saturated fats activate the randle cycle? like hydrogenated coconut oil, MCT oil....
 
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haidut

haidut

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Oddly, Peat keeps insisting (see the latest interview) that the body prefers storing PUFA instead of burning them. I think it's the main reason he reduced his consumption of fat by a lot. He used to eat a lot of fat but said he was afraid of PUFA accumulation, and therefore cut it down.

"I think that proportion is good for most people; I felt good while I was averaging about 50% fat, but I decided to reduce it to avoid PUFA accumulation, so now I’m trying to keep sugar over 50%, fat a lot lower." (Ray)​

I think the key difference is that this is a study for fat metabolism under stress. I mentioned this in my original post but maybe the message got lost or was unclear. When you eat fat in a meal and are not under stress then SFA gets oxidized (especially the SCFA and MCT portions of it) while PUFA gets stored. However, under stress and thus increased lipolysis it is PUFA that gets released since storage contains mostly PUFA and this is what causes the damage. So, until tissue stores are mostly SFA lipolysis should be kept as low as possible.
@Mauritio @rei @Cirion
 

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