Thursday, April 14, 2011

Palmitic acid: the horror never ends addendum

Okay, Victoria sent me the full pdf.

This group used 0.2mmol/l or 0.5mmol/l palmitate conjugated to bovine serum albumin. All other fatty acids were completely excluded. No semblance of physiological mixtures were involved.

But guess what, they had a living mouse model too!

Now you have to be wondering exactly how they managed to get a mouse to have 0.5mmol/l of palmitate in its bloodstream, to the exclusion of all other fatty acids, during a glucose tolerance test. After all, their test tube model used pure palmitate, surely they used the same conditions in their mice? This is a Nature paper after all.

How did they perform this near miracle? Well the methods section (when you finally find it tacked on to the end of the paper, an afterthought down beyond the references) doesn't mention any attempt to measure live mouse fatty acids at all. They didn't. WTF, this got published in Nature!

The diet used was good old commercial 5TJN. When I downloaded the composition pdf from the Test Diet website to my laptop it said I'd already downloaded it some time before..... It's popular!

Here's the link, it won't embed:

www.testdiet.com/PDF/5TJN.pdf

How much sugar would you like with your Crisco? Remember, always ask for your favourite lipotoxin by name...

NO NO NO.

JUST SAY NO.

Say no to Crisco.

As so often happens, this paper details feats of molecular and cellular manipulation of breathtaking complexity. How can anyone be capable of doing this and yet be so stupid? Awesome!

Peter

And it gets worse. The stats were done on "Prism 5.0 for Macintosh". OMG they're Mac users. It shouldn't be allowed. Their laptops should be confiscated forthwith. Now. I'll have them please.

27 comments:

SamAbroad said...

Dang I must have a 'red dye' deficiency. Must get some supplements.

Quality stuff Peter, your humourous take makes the idiocy bearable.

Peter said...

Yes, I'd wondered if Red Crisco was worse than the white stuff.

Reminds me of the original medetomidine bottle labels, they were blue, exactly the colour of the gums of a patient under medetomidine sedation.

Atipamezole (the reversal agent) had a red label, the colour of their gums after reversal of medetomidine sedation.

I still wonder if people in drug companies have a sense of humour! Perhaps.

Peter

Jared M Johnson said...

Trans fats anyone? How do they not control for trans fats in 2011?

rmv said...

So, hold on a second.

You're not a fan of crappy science?

Peter said...

I probably just want their laptops...

Peter

Aaron Blaisdell said...

My warning bells went off, too, when I read about the live mouse experiments embedded in the paper. So I contacted the authors and the first author sent me a PDF of the High Fat diet, and I gasped when I read how much Crisco was in the diet! And the other offenders in there are a real hoot, too. But, at least the diet might be a good enough approximation of the SAD high fat (and high carb) diet, though not a hyperlipid diet the good ol' paleo/primal way.

Aaron Blaisdell said...

Peter, the authors either have a serious case of cognitive dissidence or a series case of morbid humor. The Red dye points to the latter.

Anna said...

"This is a Nature paper after all."

Oh, that tabloid? Inquiring minds want to know, after all.

Peter said...

I'll upgrade to the Sun then....

Peter

Tony Mach said...

I am still waiting for the studies that shows just how dangerous water and air are - by using distilled water and pure oxigen.

Tony Mach said...

And these Testdiet guys are funny:
Linolenic Acid 0.16%
Omega-3 0.13%

Linolenic acid is a n-3 fatty acid according to wikipedia,[1] but it is known that wikipedia is inferior to peer-reviewed journals and that it is an unreliable source.[2][3][4][5] Our conclusion is therefore that linolenic acid is not a n-3 fatty acid. Futhermore both the n-3 to n-6 ratio and the absolute amount of both omega fatty acids are well within physiological margins considered healthy.[6][7][8]

And now with healthy soybean oil!

Ed said...

Hrmm Crisco says they have no trans fats in them. http://www.crisco.com/Products/ProductDetail.aspx?groupID=17&prodID=315 but they are 50% PUFA.

Ed

Chris Sturdy said...

Which paper is this? Did you post a link to it? Could you? Thanks!

Peter said...

Chris, it's this paper from this post

Ed, the formula of Crisco has varied hugely over the years. You can bet the Western Diet is formulated with the trans version, probably supplied from Axen and Axen's private stash of the 17% solution...

Tony, back when I was a Green Peace member I read a book on the hazards of industrial chemicals which eventually got to the level of quoting drowning statistics and yet WATER (gasp, horror) is piped to virtually every house in the land..... I exaggerate only slightly. As for oxygen toxicity, 100% will undoubtedly kill you, just more slowly than 0%.

Aaron, I like the humour idea but have my doubts...

Peter

Stan (Heretic) said...

Re: back when I was a Green Peace

Peter - no you didn't! Did you? (worried)

karl said...

I think a letter to the editors of Nature is in order.

Not sure how this stuff happens - has peer review become a clique of buddies of the authors or is this just the nature of Nature..

Dr. Curmudgeon Gee said...

hahaha. XD.
thanks.

Peter said...

Stan, yes, and I look back with incredulity...

P

Peter said...

...but then I was avoiding sat fats, eating whole meal bread and a ton of fruit in those days. Lentils, chick peas, pasta (wholemeal of course) and fresh squeezed orange juice with croissants and Nutella as a special treat. No wonder really.......

P

blogblog said...

@Tony Mach,
alpha-linolenic acid is unequivocally a n-3 fatty acid.

Unfortunately most nutrition researchers aren't proper scientists. They aren't aware that much of the stuff that they write is total bollocks.

blogblog said...

The French have always banned hydrogenated fats. It could help explain the "French Paradox".

gallier2 said...

@blogblog

no, French have never banned trans-fats. What French legislation has banned since 1912 is oil with more the 5% linolenic acid because of their higher rancidity. You couldn't buy linseed oil for human consumption for instance.
As European law has now precendence over French law, that ban has been lifted now for some years.
The French Paradox can be simply explained by the fact that saturated fat isn't saturated fat (cognitive dissonance in fact) when it comes from traditional food.
The worrying part is that the sat-fat phobia that starts to decline in the anglosphere has not reached its peak yet in francosphere.

gallier2 said...

Concerning the food composition, there is more trans-fat in the chow than saturated fat. Here my calculation:

polyunsaturated
o6 1.7 + 0.02 = 1.72
o3 0.16 + 0.13 = 0.29
mono = 4.30
sat = 6.42
======================
sum = 12.73 g

total fat was 19.90g
so trans-fat is 19.90 - 12.73 =
7.17g

more than sat fat

As for the distinction between omega 3 and linolenic acid, I think they are right, they also distinguished between arachidonic and linoleic acid which are both omega6 fats. They used omega3 label to avoid to write eicosapentanoic and docosahexanoic acid the two main long chain o3 fats.

blogblog said...
This comment has been removed by the author.
blogblog said...

1) alpha-linolenic acid (ALA) is an omega-3 PUFA.

2) gamma-linolenic acid (GLA) is an omega-6 PUFA.


If the authors can't even understand such rudimentary basics as the systematic nomenclature of fatty acids they shouldn't be doing nutrition research.

ps. The wikipedia article is correct.

JorgeA said...

dont take it on Macs. Its about the ideas, not the computers. Plenty of good statistical software runs on Macs (e.g. R)

Peter said...

JorgeA, I'm just shocked that people this dim use Macs. They should be relegated to virally infected PCs running Windows 95 at best... Or maybe an abacus. They certainly should never be let near a Mac.

Peter