Palmitoleic acid -- good or bad?

[Zeta]

As I claimed elsewhere in trying to figure out which nuts are healthy -

 

If one added [to my table of nuts and the like and nutritional content] palmitoleic acid -- the ω-7 FA macadamias are rich in -- macadamias would appear even better than they do.

 

And as indicated in a study cited by Dean in a separate thread about the Time magazine story about dietary fat:

 

Ruminant trans-palmitoleic acid was inversely associated with type 2 diabetes.

 

But there are some negative associations between palmitoleic acid (16:1) and health. A good pop summary is here, in "Omega-7: The New 'Healthy Fat'?"

 

Does anyone have a handle on the research into palmitoleic acid and health? My ~50%-well-researched conclusion squares with the pop summary above. I'm not sure the negative associations between blood levels and poor health markers mean much, since we synthesize a lot of it. But I really don't know.

 

Thanks,

Zeta (not ready to press "Buy" on next, currently macadamia nut-less, nut order)

 

[Michael R]

Zeta, I apologize for taking so long to reply, particularly if your trigger finger itch finally overrode your frontal cortex: I didn't have time to make a proper reply, and still don't. But for now, I will say that I briefly got very excited about the palmitoleic acid story, wasted a lot of time securing a quality and low-cost source (wound up back in the arms of Nuts.com ...) and the more I dug into it the more problematic it appeared to be. Suffice it to say that I am pretty skeptical that there are actual metabolic benefits to palmitoleic acid consumption, particularly in the form of its whole-food sources (macadamias, mac oil, and especially high-fat dairy — this latter, however, considered only as a source of palmitoleate).

[Zeta]

Michael, I appreciate the replies, whenever they arrive. (I made my purchase, and it did not include macs.)

 

I just did some more digging. I'm actually more impressed with the studies using whole-food sources, well, using macadamia nuts, in particular, than with other studies, but even here, studies with tree nuts seem to yield such similar, nut-independent results, that I suspect the nuts are just displacing something harmful/less beneficial.

 

I don't know. I love the taste of macadamia nuts, and on days when I feel I might be getting too much protein, they're a good, low-carb source of low-protein energy. A lot of SFA, sure, but surprisingly little 16:0 (olive oil has 50% more per calorie) which is the SFA we should mostly be worried about. (Well, macs are unique among nuts in that they have a non-trivial amount 20:0, as well, but you'd have to eat a lot of them for it to be a health problem.)

 

Zeta

[Zeta]

Did some more digging (I really want to be able to eat macadamia nuts since they're so tasty...). There are no solid studies on macadamia nut consumption per se (as opposed to consumption of nuts in general), but Manohar L. Garg et al have published at least two studies focused on just macadamia nuts. Both are non-controlled, non-industry-financed intervention studies in hypercholesterolemic men. Both studies showed significant improvement in risk markers. One, available online, reports only a slight reduction in weight ("Total energy and protein intakes were similar at baseline and postintervention in all the hypercholesterolemic subjects"), and a slight decrease in overall energy intake -- slight enough I doubt the improvement are a CR effect. But percentage carbohydrates and SFA were reduced, which are of course confounding factors. All in all, not a great study. (1) But it doesn't seem like macadamia nuts are necessarily so much worse than other nuts.

 

And as far as interventions with pure palmitoleic acid go, the results seem contradictory.

 

http://www.ncbi.nlm.nih.gov/pubmed/8006520 says palmitoleic is more like palmitic acid in its effects on blook lipids, but this --

 

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4274120/

 

-- (in hamsters, though) shows it's more like oleic.

 

(1) Macadamia Nut Consumption Lowers Plasma Total and LDL Cholesterol Levels in Hypercholesterolemic Men.