Wednesday, April 13, 2011

Palmitic acid: the horror never ends

Chris forwarded me a link to this study. Read about inflammasones in tissue culture and quake. Here is the relevant line:

"These findings provide insights into the association of inflammation, diet and T2D."

It gets even better. Here is the best line from the press release:

"These results support the idea that inflammation plays a role in chronic disease," says Ting. "The simple message is to avoid fatty foods as much as possible."

OK, you take isolated cells, bathe them in 2mmol palmitic acid and they become unhappy. This is supposed to have something to do with eating a high fat diet?????

Just for fun I'm going, in my head, to eat some (gasp, horror) palmitic acid. Please don't do this at home, you probably don't want to inflame your inflammasomes.

I'm looking through my refrigerator for some palmitic acid but I notice that all there is in my fridge is Food. Bugger. What comes closest? Maybe butter??? Butter is undoubtedly Food, but it does have rather a lot of palmitic acid. Let's give it a try.

Half a pound of butter, here I come. Mmmmmmm. Nice. Yummie.

Now let's measure my blood palmitic acid levels . OOOOOh, post prandial triglycerides are up! Right on, I'm gonna die, some time soon. But what about the acid, the pamitic acid?

Ah, FFAs are also up up up. Success! 500, 600, 700, yes, 800micromol/l. If I really am in luck I might make that 2000micomol/l hit and drop right in to the inflammasome mediated diabetes zone. You know, that palmitic acid trip to nowhere.

Oh, but except for feeling a bit nauseous from all that butter in one go, I feel fine. Perhaps because I don't really have 2mmol/l palmitate in my blood stream after all. Double bugger. It seems like there is major, like MAJOR, contamination of my blood palmitate with oleate. Some is from the butter, some is from my own bloody liver cocking up the experiment. Using delta 9 desaturase to drop the occasional double bond in to long chain saturated fats ensures normal physiology.

Now, if I wasn't such a cheapskate I'd shell out the ackers to see if Ting et al used mixes of palmitate and oleate as well as either fatty acid in isolation. We know from the abstract that oleate does not inflame your inflammasomes... But I am a cheapskate, so I won't. Instead I'll go to this study:

"Low concentrations of oleate (0.1mM) completely inhibited palmitate-induced oxidative stress, SAPK activation, and apoptosis."

That's it, one tenth of one millimole of oleate completely negates the adverse effects of isolated palmitate.

Maybe check this one:

"Oleate alone did not cause mtROS generation and mtDNA damage, and its addition to palmitate prevented palmitate-induced mtDNA damage, increased total ATP levels and cell viability, and prevented palmitate-induced apoptosis and inhibition of insulin-stimulated Akt (Ser(473)) phosphorylation."

I could go on. No one, ever, at any time, has 2mmol/l of isolated palmitate in their bloodstream. A whiff of oleate is completely protective against the evil intentions of a researcher with a block of palmitate when viewed from the bottom of a test tube. It's called physiology. We are evolved to work this way. Knock out delta 9 desaturase and things become quite fun, but that's another story!

Citing the existing literature doesn't get you a Nature publication. Nor does it allow you to write press releases of utter stupidity to support low fat eating while simultaneously keeping yourself off the dole.



Anonymous said...

Good one Peter

Stephan Guyenet said...

Hi Peter,

You might be interested to know that dietary palmitate appears to have little or no long-term impact on palmitate in fasting FFA or in adipose (although it can be diluted a bit due to the accumulation of linoleic acid). They measured it in the Oslo diet-heart study and SFA restriction scarcely changed it:

Eating palmitate may influence postprandial FFA, but if you eat carbs with your meal total FFA are suppressed 80% or more for hours due to an insulin spike. So it strikes me as physiologically irrelevant, although it could hypothetically be relevant if carbohydrate intake is very low.

That's the reason I took down my post on palmitate.

Peter said...

Hi Stephan (and id),

Yes those fatty acid tables comparing blood and adipose tissue fatty acid profiles in the Oslo study are neat. I particularly like the increase in omega 3s which never got commented on in the text but sneaked in to the results tables.

And of course insulin increases desaturase activity as well as suppressing FFA release. Ultimately the paper and it's press release are beyond politeness!


Paul Jaminet said...


Obviously eating butter is not a good parallel to bathing cells in vitro in palmitic acid solution.

A better parallel would be to bathe your whole body in 2 mmol palmitic acid solution.

I suspect this might prove rapidly fatal, due to suffocation, thus verifying that saturated fats are evil.

Not sure how much inflammation there would be however. Some people use 2 mmol palmitic in cocoa butter lotions ( and they seem to think it is anti-inflammatory.

Anonymous said...

Hi Peter

In my new copy of nature there is an article on how phosphatidyl choline metabolites might be the cause of atherosclerosis.

So even if you prove sat fat in food is harmless, now you must prove that the lecithin in eggs and liver and meat is not killing you, too. Never mind the NAFLD from choline deficiency.

The global diet/heart lipid hypothesis - somewhere there is something that is a saturated fat, is kind like a saturated fat or is associated with saturated fat, and it is killing us if we eat it

The moving target just keeps moving.

Funny the way that pesky oleate always tags along with big brother whenever we eat animals.

Unknown said...

Dr. Eades tweeted this study the other day - seems pertinent.

Vladimir Heiskanen (Valtsu) said...


Chris Masterjohn just wrote a nice essay about that:

Anonymous said...

Nice post Peter...

Maybe you noticed that the second paragraph of the NS article contains the following sentence:

To investigate the effects of fatty food on the immune system, researchers led by Jenny Ting at the University of North Carolina, Chapel Hill, exposed mouse immune cells called macrophages to palmitate, an unsaturated fat found in many processed foods.

So either:
1. The researchers have discovered a new unsaturated form of palmitate.
2. The writer of the original press release has no idea what he/she is writing about.
3. The journalist who wrote the article has no idea what he is writing about, and/or has been lazy in simply quoting the original press release verbatim.

I suspect one or both of the later two explanations as the abstract correctly defines palmitate as an SFA.

Anonymous said...

Kind of reminds of this researcher (won't name names... cough, cough... The China Project) who concluded that isolated casein caused an increase in cancer, then proceeded to attribute this same effect to ALL ANIMAL PROTEINS, all the while forgetting that in the case of casein, the latter often comes with... cough, cough... whey, which happens to have completely different properties when isolated, namely cancer-inhibiting properties... Damn human body physiology!!!!! Why won't you agree with all my compartmentalization and nutritionism/reductionism!!!!

Paul Jaminet said...

Hi Valtsu,

I also discussed that article, here:

Peter said...

Hi hithaeglir,

I missed that! As good as the paper a few months ago using fully hydrogenated MCT oil but calling it transfat in the actual title of the paper!!!!!!!!!!

Emily, it's interesting. We humans don't really do de novo oleate as much as palmitoleate, so oleate may be a surrogate for pork or, heaven forbid, olive oil intake. Palmitate smells of de novo lipogenesis under very high carbohydrate, especially fructose, intake... I think you could play all sorts of games with this ratio but then you would need some intervention studies to check them out.

Paul, hmmm Bodyshop lotions. Yes, handle with care if provided in 5000 litre containers... Dropping the barrel on your foot might cause significant inflammation too.

Amen Eric


Paul Jaminet said...

Peter, careful, you might be working up a Nature paper there!

Peter said...

Uh, outed........


blogblog said...

I stumbled on a guide for feeding pets rats recently.

Some very unhealthy and potentially highly toxic foods for rats include corn, citrus, peanuts, sunflower seeds, avocados and broccoli. These just happen to be the "healthy" foods that the medical authorities recommend we humans eat in abundance.