May
2008
Dear Mark: Nuts
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Nutty
Dear Mark,
Can you give me more explanation about nuts and seeds? I eat a ton of them and am always confused about which ones are actually nuts and which are seeds and which are legumes. Does it make any difference if you eat them whole, roasted, raw or as nut butter?
Thanks to reader Charlotte for these questions in response to last week’s “Get Primal” post. The classification question does get tricky.
Nuts themselves are actually a kind of fruit, specifically “dried fruit.” But not everything we consider nuts are really nuts. Some are actually seeds, often within fruits or even legumes. A hazelnut is, indeed, a nut. An acorn is also a variety of “true” nut, as are pecans, walnuts and chestnuts. But an almond, for example, is a seed inside a fleshy fruit’s (a.k.a. drupe’s) pit. A pistachio is a seed within a fleshy fruit. Pine nuts are seeds. Cashews are seeds. Peanuts are the seeds of a legume. Technically speaking, all nuts are fruits, and a “true” nut is indehiscent (they don’t – by themselves – open to spread seeds), hard-shelled and generally one-seeded.
But let’s look at all this from a practical perspective: what’s good to eat? “Nuts” in the broad culinary classification contain protein. Big plus. They tend to be high in certain B-vitamins, vitamin E, and many minerals. Another plus. Low carb. Yet another plus. But not all “nuts” are created equal. Some, like peanuts, have high levels of omega-6. As we’ve said a lot lately, we moderns seem to get way more than enough of omega-6 in our diets. Walnuts, for example, offer a nice dose of omega-3. Almonds are a great source of phytochemicals, contain calcium, and are even lower in carbs than most.
And then there’s the issue of aflatoxins, dangerous metabolites produced by certain mold varieties. Aflatoxins are common in what we usually refer to as “tree” and “ground” nuts, including almonds, walnuts and pecans as well as peanuts and cashews. The toxin has been shown to have carcinogenic, mutagenic and immunosuppressive properties. While certain farming practices can reduce the problem, the aflatoxin related molds are considered at least somewhat inevitable. Peanuts are often said to have the highest concentration of aflatoxins, and they are among the most heavily (pesticide) sprayed food grown.
In terms of roasted versus raw, I’d recommend raw to avoid the oxidation that happens during heating. However, there are increasing challenges to the sale of truly raw (untreated) nuts. The Cornucopia Institute offers a great deal of information on the recent raw almond controversy, but all California grown almonds now have either chemical or high heat treatments. The change came after raw almonds were believed to be connected with two salmonella cases, although farming practices vary considerably and may have contributed to the problem. Regarding nut butter versus nuts themselves, it’s your choice. However, be sure to select nut butter (I recommend almond butter) without added ingredients, especially added sugars. And, again, I’d favor raw and organic over conventional and roasted.
Thanks for the questions, everyone!
steffenz, Marcio Cabral de Moura, sproutgrrl Flickr Photos (CC)
Further Reading:
Modern Forager: Ten Staples of a Well-Stocked Kitchen
I love nuts and eat them everyday, except peanuts.
I would just add that some (myself included) have difficulty digesting nuts of all types and I personally have discontinued eating them for the most part….
They “stuff” my system, cause constipation and also inflammation! Definitely not good…
Thanks for the answer guys!! I swear I should start paying you for all of the awesome advice you have given me:)
I eat so many nuts, I’m practically a squirrel;)
Serena,
Some people choose to soak them (as they would beans) to aid in digestion. Because of the mold issue, I’d keep them in the fridge though and thoroughly dry them first with towels and then spread out on a cookie sheet.
When I first discovered almond butter a few years ago, I thought the gods had personally handed me a gift. I never knew it existed before that. Okay, it would have been a gift if it had come with a lower pricetag!
And while I can handle most foods in moderation, dark chocolate covered almonds might as well be crack. I can’t have them in the house, or they vanish very very quickly.
My 4 yo son loves his cashew butter, and my husband sticks with peanut butter mostly, so we’ve got a jar for each of us. YUM!
Mark-
Good stuff, thanks so much! My husband and I are thinking about training for our next marathon, and we have been reading a lot about how certain nuts are extremely beneficial for runners because of the need for additional protein. This post contains a lot of good info on what we needed to know about.
What’s the scoop on cashews? Good? Bad? OK in moderation but almonds and walnuts are better?
Nuts!
Jen, yeah even the soaking trick doesnt help me at all!!
And here is a “nut” chart:
http://paleorecipes.blogspot.com/2008/03/all-about-nuts.html
I PERSONALLY WOULD AVOID PEANUTS
being a legume, they contain, in common with all beans, lectins, which attack the intestinal mucus membrane and, in many people, can cause “leaky gut syndrome” - and thus potentially allow whole proteins into the blood stream and may trigger an auto immune response.
see
http://www.modernforager.com/blog/2008/04/04/do-evolutionary-novel-dietary-lectins-cause-leptin-resistance/
http://www.msrc.co.uk/index.cfm?fuseaction=show&pageid=2344
http://www.krispin.com/lectin.html
all the best
markus
I’m with you Crystal, i also eat nuts everyday and love’m! I go to a fresh market and always ask them to grind up “Fresh” Almond Butter before my eyes, can’t beat it!!!
My personal story…I used to put almond butter on everything…especially chicken. Tasted so good. But then there came a time where I stopped….and I noticed something. I felt better….especially when dealing with some small sports related inflammation issues. That and I did more research into the unstable enviroment of most PUFAs (Poly unsat fats) and decided to switch up my fat sources. Now I eat mostly Sat and MUFA (with some Omega 3s from fish oil..and there is still plenty of Omega 6s from meats). I rarely eat nuts….but I still enjoy them time to time….but taking them out of my diet (well I was eating a ton of butter) completely made me feel 100x better.
I started my career working as an engineer in peanut butter product development (P&G, 1959). There wasn’t much said about aflatoxin then, but in the 60’s the lab was testing for it to be sure it wasn’t in their peanuts. However, I got uneasy about other companies who might not test for it especially when I learned it was thought that the aflatoxin mold groth was aided by darkness and moisture on the bags that the peanuts were often harvested and stored in. Then when I heard aflatoxin is an absolute cause of cancer, I gave up peanuts and peanut butter for good.
(2nd comment) I like almond and cashew butter, alone or mixed. A trick I learned in the peanut butter product developement lab that works for these other nut butters is to add a little (olive) oil and a little lecithin when you make nut butter. The lecithin helps yield a smooth butter. The proportions are not real critical - to a cup of nuts, add 1/8 cup oil and (estimated) 1 tsp of lecithin. I also add a little honey, but that’s extra. Then if you have a Vita-Mix, you’re all set. It makes a great nut butter.
Thanks for the suggestions, Tom! I’ll have to try the lecithin/oil idea.