Pistachios: Are Their Shells A Portal to Contamination, The Key To Weight Loss, or A Manicure Destruction Device?

The results of the “Fourth Nut” poll are in and the winner is a nut first cultivated in Bronze Age Central Asia,
Almost 60% of readers who took the time to vote selected the pistachio nut.

Coming in a distant second was the macadamia nut. One reader prized it because it only contained saturated fat and monounsaturated fats. Another bemoaned their candy-like quality which makes over-consumption an issue.
A couple of readers were strong proponents of Brazil nuts. This prompted me to enter a selenium rabbit hole from which I have yet to emerge. If I can escape with my selenoproteins intact I’ll let you know.
Pistachios are a fine choice from a health standpoint and seem to be embraced by all nutritional cults, with the exception of  the very nutty Caldwell “NO OIL” Esselstyn’s acolytes.

The Pistachio Principle PR Institute

I’m in the process of sorting through the nutritional studies on pistachios, and the hardest part is determining which data are sponsored by the pistachio industry.
For example, poorly researched online articles about pistachios will typically state that “research suggests” that “pistachios could help to reduce hypertension and promote development of beneficial gut microbes. They’re even gaining credibility as a tool for weight loss”
The first reference is an open access review article which clearly just wants to extoll any and all positive pistachio data and was paid for by the American Pistachio Growers. The second article comes directly from “The Pistachio Health Institute,” a PR voice for the pistachio industry.

To Shell or Not to Shell

My major dilemma was deciding if the pistachios should be shelled or left in-shell. (This has led me down the pistachio production rabbit hole).
I was concerned that the outsides of the pistachio shells could be contaminated in some way and the idea of mixing them in with unshelled nuts seemed a little strange.
If you Google images of mixed nuts pistachio you only see mixtures with unshelled pistachios.

Why, then, are most pistachios sold and consumed in-shell?
According to How Stuff Works Louise Ferguson, author of the Pistachio Production Manual believes:

Between 70 and 90 percent of pistachios develop a natural split in their shells during the growing process, After those pistachios are shaken off the trees by harvesting machines, they can be salted and roasted while still inside the shells as that natural crack allows heat and salt access to the nut, eliminating a step in the industrial process and saving processors some money.

The pistachio PR machine would also have us believe that eating pistachios in-shell can lead to weight loss:
Why choose any other nut?
This pistachios principle is based on 2 studies in the journal Appetite (seems to be a legitimate journal) by JE Painter of the department of “Family and Consumer Sciences” Eastern Illinois University in Charleston, Illinois.
I’m awaiting a full copy of the paper, but the abstract notes that students offered in-shell pistachios consumed only 125 calories, whereas those offered shelled pistachios consumed 211 calories yet “fullness and satisfaction” were similar.
My skeptical sensors were exploding when I read about this study. I doubt that it will ever be reproduced.
If we look at cost, an unofficial analysis revealed:

The pre-shelled pistachios were priced at $5.99 for 6.3 oz of nuts.
The 8 oz bag of pistachios were priced at $4.49.  After shelling he was left with 4.3 oz of nuts.
Un-shelled pistachios = $1.04 per oz.
Shelled pistachios = $0.95 per oz.
If you go the lazy route, you save $.09 per oz!

Most likely, the fourth nut will be a shelled pistachio unless readers convince me otherwise or the blather from the pistachio PR machine  annoys me too much.
The eternal fiance’e has just weighed in and tells me that women who care about their well-groomed  nails will not consume  in-shell pistachio nuts for fear of damaging their manicures.
That, my friends, is the  nail in the coffin for shelled pistachios as the fourth nut.
Pistachoprincipaly Yours,
-ACP

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5 thoughts on “Pistachios: Are Their Shells A Portal to Contamination, The Key To Weight Loss, or A Manicure Destruction Device?”

  1. Every time I eat pistachios I get heart palpitations within 12-18 hours. I’ve tried numerous process of elimination tests and it’s them, sadly, as I do love the taste and nutrition they have.

    Reply
  2. Un-shelled pistachios are better because you can lick the salt off the shells. (Has anyone else noticed how odd English can be: un-shelled pistachios have shells and shelled pistachios don’t?)

    Reply
  3. I only buy pistachios with the shells on. They are cheaper and taste fresher to me. I like the visual cue of the shells to know how many I’ve eaten. I then compost the shells. I rarely get a manicure so that’s a non- issue for me. My husband also prefers pistachios with the shells on. Pistachios are a staple in our household.

    Reply
  4. In my limited experience:
    pistachios in-shell go on sale more often than shelled pistachios; and
    I eat fewer in-shell pistachios than shelled ones.
    YMMV.

    Reply

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