2

votes

Liver fat reduced by PUFA?

Answered on September 12, 2014
Created May 03, 2012 at 9:32 PM

Possible Duplicate:
New study: Effects of n???6 PUFAs compared with SFAs

Stephan Guyenet tweeted this study recently. (If you're not following him on twitter btw you are missing out!)

http://www.ajcn.org/content/early/2012/04/03/ajcn.111.030114.short

I know it's only 10 weeks but doesn't that strike you as a surprising result?

Higher insulin, higher liver fat and a worse lipid profile on SFA compared to PUFA.

The weight gain difference was not significant so it couldn't be explained by the extra palatability of the butter compared to the PUFA (haven't read full text but presuming some kind of nasty product like soy-bean 'butter').

How can we place this study in the context of wider research?

96440612cf0fcf366bf5ad8f776fca84

(19463)

on May 06, 2012
at 04:52 PM

Yes, unfortunately most n6 PUFAs are going to be off the shelf, industrial seed oils, which by their very nature via processing will be already somewhat rancid. If you get them from, say, raw nuts or sunflower seeds, it's going to be a lot safer. So it's a good question as to the exact kind of oils that were used in the study.

E5c7f14800c5992831f5c70fa746dc5c

(12857)

on May 06, 2012
at 11:55 AM

I rather take rat studies over clinical trials which try to claim vegetable oil is somehow better than butter based mostly on liver fat. The essentially of omega 6 has yet to be proven.

21fd060d0796fdb8a4a990441e08eae7

(24543)

on May 05, 2012
at 01:28 PM

See J. Stanton's comment below, this question is a duplicate of the earlier question located at...http://paleohacks.com/questions/110169/new-study-effects-of-n6-pufas-compared-with-sfas

21fd060d0796fdb8a4a990441e08eae7

(24543)

on May 05, 2012
at 01:27 PM

Okey dokey, will close.

121a16aded2bed8dca492d3c9662ef4c

(1327)

on May 04, 2012
at 04:10 PM

You are comparing a study in abdominally obese human subjects (cited by sarah-ann) to a study in rats. Rat studies have the benefit of being cheap and provide a direction for further investigation, but you can't say anything meaningful about the effects of an intervention until you've tested it *in humans*. Doubt this? Then let me ask you: would you take any medication that had only been tested in rats? I sure wouldn't. I don't find the human study in the least bit surprising. Omega 6 fatty acids are essential, too.

24df4e0d0e7ce98963d4641fae1a60e5

on May 04, 2012
at 03:15 PM

I have the full text. Email me at carbsane at gmail dot com and I'll share it with you through Google docs.

E5c7f14800c5992831f5c70fa746dc5c

(12857)

on May 04, 2012
at 02:13 PM

Fructose only causes liver problems when its fed without glucose to the point where it can't all be metabolized and it is turned into endotoxin by bacteria. The endotoxin is what damages the liver...

4b5be253ac1981c690689cab7e4bf06d

(3043)

on May 04, 2012
at 01:09 PM

The PUFA was high in linoleic acid. And, the authors previous paper said that replacing SFA with PUFA led to a decrease in intake and a decrease in abdominal fat, but without an overall change in weight. http://www.ncbi.nlm.nih.gov/pubmed/11914742?dopt=Abstract

24df4e0d0e7ce98963d4641fae1a60e5

on May 04, 2012
at 11:33 AM

I'm curious to know the makeup of the PUFA ... specifically the MUFA content of the oil. The palmitic acid in butter is IR inducing while MUFA includes the insulin sensitizing palmitoleic acid.

1edb06ded9ccf098a4517ca4a7a34ebc

(14952)

on May 03, 2012
at 09:56 PM

Nuts- MUFA and PUFA- are always and everywhere demonstrated to improve health markers. I am unaware of any study that shows this to be true for butter.

A2c38be4c54c91a15071f82f14cac0b3

(12682)

on May 03, 2012
at 09:53 PM

http://paleohacks.com/questions/110169/new-study-effects-of-n6-pufas-compared-with-sfas#axzz1tqWJodLS

A727956fa3f943057c4edb08ad9e864e

(4183)

on May 03, 2012
at 09:38 PM

Care to elaborate?

1edb06ded9ccf098a4517ca4a7a34ebc

(14952)

on May 03, 2012
at 09:35 PM

This does not strike me as surprising one bit.

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4 Answers

1
00c8eb3f6e6a1884216044ca29cf868a

on May 04, 2012
at 07:18 PM

This is an exact duplicate of this question, asked and answered in great detail one month ago: http://paleohacks.com/questions/110169/new-study-effects-of-n6-pufas-compared-with-sfas

Someone should close this as an exact duplicate. (I can't, as I'm not a moderator.)

21fd060d0796fdb8a4a990441e08eae7

(24543)

on May 05, 2012
at 01:27 PM

Okey dokey, will close.

1
E5c7f14800c5992831f5c70fa746dc5c

(12857)

on May 04, 2012
at 02:09 PM

Maybe reducing liver fat isn't always good...

"A diet enriched in saturated fatty acids effectively reverses alcohol-induced necrosis, inflammation, and fibrosis despite continued alcohol consumption. The therapeutic effects of saturated fatty acids may be explained, at least in part, by reduced endotoxemia and lipid peroxidation, which in turn result in decreased activation of NF-??B and reduced levels of TNF-?? and Cox-2. "

http://jpet.aspetjournals.org/content/299/2/638.full

"Rats in group 1 were fed a fish oil-ethanol diet for 6 weeks. Rats in groups 2, 3, and 4 were fed fish oil and ethanol for 6 weeks. Ethanol administration was stopped at this time, and the rats were switched to isocaloric diets containing dextrose with fish oil (group 2), palm oil (group 3), or medium-chain triglycerides (group 4) as the source of fat for an additional 2 weeks. Rats in groups 5 and 6 were fed fish oil-ethanol and fish oil-dextrose, respectively, for 8 weeks. The most severe inflammation and fibrosis were detected in groups 1 and 5, as were the highest levels of endotoxin, lipid peroxidation, and mRNA for Cox-2 and TNF-??."

http://onlinelibrary.wiley.com/doi/10.1002/hep.510260622/abstract

http://co2factor.blogspot.com/2012/04/saturated-fat-versus-polyunsaturated.html

121a16aded2bed8dca492d3c9662ef4c

(1327)

on May 04, 2012
at 04:10 PM

You are comparing a study in abdominally obese human subjects (cited by sarah-ann) to a study in rats. Rat studies have the benefit of being cheap and provide a direction for further investigation, but you can't say anything meaningful about the effects of an intervention until you've tested it *in humans*. Doubt this? Then let me ask you: would you take any medication that had only been tested in rats? I sure wouldn't. I don't find the human study in the least bit surprising. Omega 6 fatty acids are essential, too.

E5c7f14800c5992831f5c70fa746dc5c

(12857)

on May 06, 2012
at 11:55 AM

I rather take rat studies over clinical trials which try to claim vegetable oil is somehow better than butter based mostly on liver fat. The essentially of omega 6 has yet to be proven.

0
4b5be253ac1981c690689cab7e4bf06d

(3043)

on May 04, 2012
at 01:08 PM

I dont have the full article, but the Clinical Trial has the PUFA or SFA energy at 15%, and the PUFA as "rich in linoleic acid, omega-6." (http://clinicaltrials.gov/show/NCT01038102) Which means this is a high carb diet.

Two things to keep in mind. First, looking at just one aspect of the body misses several key points. One main reason why Paleo people like saturated fat is that PUFA is very easily oxidized, and can cause inflammation in the body. It may not show looking at one particular piece of the body, but the inflammation over a long period can cause issues.

Secondly, Paleo tends to be a lower carb, and thus lower insulin producing diet than the typical clinical or standard diet. Thus, how SFA acts within a low carb diet is different than how it acts in an environment that includes lots of carbs.

96440612cf0fcf366bf5ad8f776fca84

(19463)

on May 06, 2012
at 04:52 PM

Yes, unfortunately most n6 PUFAs are going to be off the shelf, industrial seed oils, which by their very nature via processing will be already somewhat rancid. If you get them from, say, raw nuts or sunflower seeds, it's going to be a lot safer. So it's a good question as to the exact kind of oils that were used in the study.

0
96440612cf0fcf366bf5ad8f776fca84

(19463)

on May 04, 2012
at 10:05 AM

Except that when most people here say PUFAs are good for us, they don't refer to industrial oils in large quantities, the refer to n3's via fish. Also, fatty liver (NASH) is caused by high amounts of fructose, so perhaps a period of limiting fructose is a better way to go?

This would be an interesting development if true. Anyone have access to the full study to see if the data matches the conclusion?

It's certainly conceivable that if you're eating saturated fat, your body will burn what you consume rather than taking it from fat stores - one of those being your liver's storage.

So perhaps it's a question of the lack of saturated fats that causes our bodies to burn our stored fat rather than the presence of n6 PUFAs? Just a thought. If so, we'd also expect fat loss elsewhere, not just in the liver. Perhaps the rest of the paper has this data one way or another?

4b5be253ac1981c690689cab7e4bf06d

(3043)

on May 04, 2012
at 01:09 PM

The PUFA was high in linoleic acid. And, the authors previous paper said that replacing SFA with PUFA led to a decrease in intake and a decrease in abdominal fat, but without an overall change in weight. http://www.ncbi.nlm.nih.gov/pubmed/11914742?dopt=Abstract

E5c7f14800c5992831f5c70fa746dc5c

(12857)

on May 04, 2012
at 02:13 PM

Fructose only causes liver problems when its fed without glucose to the point where it can't all be metabolized and it is turned into endotoxin by bacteria. The endotoxin is what damages the liver...

24df4e0d0e7ce98963d4641fae1a60e5

on May 04, 2012
at 03:15 PM

I have the full text. Email me at carbsane at gmail dot com and I'll share it with you through Google docs.

24df4e0d0e7ce98963d4641fae1a60e5

on May 04, 2012
at 11:33 AM

I'm curious to know the makeup of the PUFA ... specifically the MUFA content of the oil. The palmitic acid in butter is IR inducing while MUFA includes the insulin sensitizing palmitoleic acid.

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