Lipolysis preferentially releases PUFA from adipose tissue

[haidut]

...compared to SFA and/or MUFA. This topic is considered highly controversial in Peat-land, mostly because of the dearth of studies dealing with it. I must have received hundreds of emails at this point criticizing Peat's stance on this issue and claiming that there is no evidence for preferential PUFA release from adipose tissue compared to SFA/MUFA. I hope the study below will answer some of that criticism and, more importantly, will give people a pause before they embark on a lipolysis-maximizing endeavor such as exercising on an empty stomach, prolonged fasting, intake of beta-agonists (popular among athletes), etc.

Selectivity of fatty acids on lipid metabolism and gene expression - PubMed
"...The release of up to fifty-two different individual fatty acids was recently studied by comparing the fatty acid composition of FFA with that of fat cell TAG from which they originated through lipolysis (Raclot & Groscolas, 1993). For most of the fatty acids, the relative proportion by weight in FFA was significantly different from that in the TAG. Compared with TAG, released FFA were enriched in some PUFA and depleted in long-chain saturated and monounsaturated fatty acids. The mobilization of the most-readilymobilized fatty acid (18:5n-3) was 15-fold higher than that of the least (24:1n-9). Among major fatty acids, the mobilization of eicosapentaenoic acid (20:5n-3; EPA) was five times higher than that of 20:1n-9. For a given number of double bonds, the mobilization decreases with increasing chain length, whereas for a given chain length, it increases with increasing unsaturation. Thus, fatty acids are not mobilized in direct proportion to their content in adipose tissue TAG, but selectively according to molecular structure. Generally, fatty acids are more readily mobilized from fat cells when they are short-chain and unsaturated, and when their double bonds are closer to the methyl end of the chain. In addition to this previous work, more recent studies have sought to determine whether the mobilization of fatty acids is a general metabolic property of adipose tissue, the nature of the underlying mechanisms, and the physiological relevance and implications for health."

 

[Lollipop2]

Remarkable how correct Peat keeps being as more research gets done.

 

[incrp]

Why would this report "give people a pause before they embark on a lipolysis-maximizing endeavor" I would have thought it would encourage fat burning to reduce the stored PUFA and replace fat stores with consumed saturated fats or by de novo lipogenesis, or am I misunderstanding this.

 

[Hugh Johnson]

Why would this report "give people a pause before they embark on a lipolysis-maximizing endeavor" I would have thought it would encourage fat burning to reduce the stored PUFA and replace fat stores with consumed saturated fats or by de novo lipogenesis, or am I misunderstanding this.

Because you typically have so much PUFA that there is no way your liver can get rid of it if it comes out fast. So it just poisons you.

Additionally, this means there is even less motivation to do it. The body already dumps PUFA and will get rid off anyway. Trying to speed up the process is pointless and damaging. Minimizing fatty acid release allows the liver to deal with PUFA and body to heal.

 

[Amazoniac]

It's a great find. Why this isn't getting more attention? It took one day for the second comment to appear. Consider changing the title to: '23-year-old article looking for love'.

Interesting, the 1% argue that fatty acids with decreased fat solubility (↓ length and ↑ unsaturation) are more accessible and susceptible to enzymatic liberation.
A tissue composition normalization from diet was my first thought when I noticed that the most affected fatty acid (C18:5n-3) is imaginary (6).

- Selectivity of fatty acids on lipid metabolism and gene expression

Spoiler

"Adipose tissue from animals fed on a laboratory-chow diet or semi-synthetic high-fat diets containing fish oils differing in their fatty acid composition was used throughout most of these experiments. It might be that the dietary treatment could be responsible for confounding effects due to the recent enrichment of adipose tissue in specific fatty acids. Then, it could be proposed that the preferential mobilization of the most-highly-unsaturated fatty acids is related to their high proportion in dietary fat according to the ‘last in – first out’ hypothesis (Ekstedt & Olivecrona, 1970). However, this situation was not observed, and the mobilization rate of individual fatty acids depended on molecular structure according to the same relationship as those described previously, whatever the dietary treatment and, consequently, whatever the fatty acid composition of adipose tissue (Raclot & Groscolas, 1993; Raclot et al. 1995b). Thus, the selectivity of fatty acid mobilization is an intrinsic property which originates from molecular structure and represents a general metabolic feature of adipose tissue (Table 1)."

⬑ Differential mobilization of white adipose tissue fatty acids according to chain length, unsaturation, and positional isomerism ?

Spoiler

"About 50 mg fat cells (equivalent to 1.2 x 10^5 cells with an average 0.4 pg mass) was incubated in 20-ml polypropylene flasks containing 4 ml KRBA and glucose (5 mmol/l). Incubations were done in duplicate for 2 h at 37%, under O2/CO2 95%/5% and with a 120-stroke/min agitation rate. To obtain large amounts of FFA for further analysis, their release was maximally stimulated by adding noradrenalean (the main lipolytic hormone in mammals) at a final concentration of 10^-6 mol/l. Under these conditions, lipolysis was stimulated by about tenfold and the molar ratio FFA/glycerol in the medium was close to 3/1. This indicates that the major fate of FFA after TAG hydrolysis was their transfer out of the cells. FFA present in the medium at the end of incubation represented the net efflux of FFA."

⬑ Selective release of human adipocyte fatty acids according to molecular structure

Spoiler

 

[looking2grow96]

I'm curious what you guys think about this study: Overfeeding of Polyunsaturated Versus Saturated Fatty Acids Reduces Ectopic Fat

@Amazoniac @haidut

 

[incrp]

Because you typically have so much PUFA that there is no way your liver can get rid of it if it comes out fast. So it just poisons you.

Additionally, this means there is even less motivation to do it. The body already dumps PUFA and will get rid off anyway. Trying to speed up the process is pointless and damaging. Minimizing fatty acid release allows the liver to deal with PUFA and body to heal.

How much PUFA you have stored is individual and would depend on how much you have consumed, what diet you have and probably how much and what type of exercise you do on a regular basis. The rate of oxidation will depend on demand. It sounds like you are suggesting minimise activity to reduce the rate of PUFA oxidation really?

 

[Amazoniac]

I'm curious what you guys think about this study: Overfeeding of Polyunsaturated Versus Saturated Fatty Acids Reduces Ectopic Fat

@Amazoniac @haidut

I haven't read, but you can find relevant information by the end of Mito's writing:
- Nonalcoholic Fatty Liver Disease

 

[laleto12]

What if you are a lets say, young who doesnt have lots of PUFA stored. Would lypolisis be bad then still?

Get so ripped that burn all pufa and power through the detox?

 

[Hugh Johnson]

How much PUFA you have stored is individual and would depend on how much you have consumed, what diet you have and probably how much and what type of exercise you do on a regular basis. The rate of oxidation will depend on demand. It sounds like you are suggesting minimise activity to reduce the rate of PUFA oxidation really?

If activity feels bad or causes issues, yes. I suggest keeping eating lots of carbs and not doing anything excessively stressful. And niacinamide etc can help.

 

[Amazoniac]

There can be underestimation of the polyunsaturated fat content of adipose tissue:

⬑ Selective release of human adipocyte fatty acids according to molecular structure

"The subjects comprised eight young, healthy, drug-free nonobese women undergoing plastic surgery. Age and body mass index were 31±4 years and 24±2 kg/m² respectively. Mammary adipose tissue was collected at the beginning of the operation performed in the morning."​

​

Spoiler

The most affected fatty acid was Environmental Protection Agency (EPA). Fortunately, the fragile fatty acids represented a small fraction of total and there was no change to the predominant one (terminoleic acid). We can lump together those that increased (highlighted) and then discount the difference from the original composition to know how concerning this phenomenon are. Their sum:

TAG: 0.97%​

NEFA: 1.51%​

​

NEFA − TAG = 0.54%​

- Computational model of in vivo human energy metabolism during semi-starvation and re-feeding

"Figure 10A shows that the daily average lipolysis and TG synthesis rates were initially balanced at 140 g/d."​

To be radical and apply the factor above to the amount lipolized in day:

140 g/d * 0.5% = 0.7 g/d​

1 mg of Dio-tocopherol would be enough to take care of this fraction:

- Incomprehensive/ble Notes On Choline​

 

[Megamole]

So how does one lose weight without burying themselves in a pile of PUFA? Don’t suppose there’s some way to supercharge glucoronidation of PUFA is there?

 

[Peatful]

There can be underestimation of the polyunsaturated fat content of adipose tissue:

"The subjects comprised eight young, healthy, drug-free nonobese women undergoing plastic surgery. Age and body mass index were 31±4 years and 24±2 kg/m² respectively. Mammary adipose tissue was collected at the beginning of the operation performed in the morning."​

​

Spoiler

View attachment 36597

The most affected fatty acid was Environmental Protection Agency (EPA). Fortunately, the fragile fatty acids represented a small fraction of total and there was no change to the predominant one (terminoleic acid). We can lump together those that increased (highlighted) and then discount the difference from the original composition to know how concerning this phenomenon are. Their sum:

TAG: 0.97%​

NEFA: 1.51%​

​

NEFA − TAG = 0.54%​

- Computational model of in vivo human energy metabolism during semi-starvation and re-feeding

"Figure 10A shows that the daily average lipolysis and TG synthesis rates were initially balanced at 140 g/d."​

To be radical and apply the factor above to the amount lipolized in day:

140 g/d * 0.5% = 0.7 g/d​

1 mg of Dio-tocopherol would be enough to take care of this fraction:

- Incomprehensive/ble Notes On Choline​

Excellent
Thank you