We were having a discussion at the San Diego paleo meetup today and someone said cashews are legumes instead of nuts and therefore are not paleo. Suddenly I wondered why a legume that looks like a nut would be less healthy to eat than a real nut. All are seeds that do not want to be eaten and all contain phytic acid and lectin and have poor omega 3/6 profiles. So why is it that nuts are considered more paleo and legumes are considered bad? (And for the record, I checked google and see that cashews are apparently considered 'seeds' and not nuts NOR legumes)
This is a very good question, and I've wondered this for a while. I tend to just avoid nuts and seeds altogether, but it still remains a very valid question. We want to know the reasons behind the decisions we make.
My best guess is that there is substantial evidence that humans have been consuming nuts and seeds for quite a long time, whereas legumes have only been consumed for around 10,000 years.
Now, this may not be a sufficient justification for their substantial use in the diet, however most legumes are also toxic if not cooked, whereas many nuts and seeds can be consumed raw. This is likely a large factor in it's "paleoness" as well.
Perhaps they contain differing levels of offending substances(lectins, protease inhibitors, etc), but I'm not sure. If anyone has some hard data on the subject, I'd be very interested in it.
Just found out something interesting. Cashew nuts have urushiol poison in the shell. That's the same stuff that gets you in poison ivy! Another interesting point, only higher primates are supposed to get poison ivy, but of course, that is on the skin. The response is actually more like an allergic autoimmune response. THe urushiol oil does not hurt you but in many people, the overactive immune response causes mass damage to the tissue. I wonder what would happen if you actually ATE some of this stuff! Maybe other animals would then be also effected?
But here is why I think this is so interesting. The cashew has considerable defenses via its hard shell covered with poison. But the nut inside is totally edible even raw! You just need get the shell off safely. Sometime in prehistory, those who lived in Brazil figured out a safe way to do this by steaming or cooking the shell to destroy the poison first. Then they could safely get at the nut. I wonder if all this defense mechanism makes it likely that cashews might have fewer and less powerful defense lectins inside the nut itself since it has so much defense incorporated into the shell?
Anyway, seems like cashews fall outside the basic paleo categories in some ways. It's like a nut but it's a seed. It can be eaten raw but you must cook it to get at it safely. You have to cook the shell only, not the nut. It is definitely a prehistorical tribal food so it could have been eaten in the paleo.
Very belated comment to this - Cashews are NOT legumes. The person may have confused them with peanuts, which are in the legume family of plants. Cashews are in the Anacardiaceae family related to mangoes, poison ivy and sumac (poisonous and otherwise). Some of the plants in that family include some highly toxic compounds in some parts. Cashews have to be heat treated to be edible, even the so called "raw" cashews.
Also, cashew are indeed seeds, but so are all nuts. (or at least the edible portion)
Heat treated cashews also contain lectins! because lectins to a large part are NOT destroyed by heat. The lectin and phytate questions are very important with respect to nuts. I do not eat nuts any more because they have a very, very negative impact on your joints. But not only this: nuts have an allergenic potential too. Look at the phytate contents: hazelnut 1.91%, walnut 0.65-2.38%, almond 1.35-3.22%, cashew 0.63-1.97%, peanuts 1.05-1.76%, peanuts toasted and salted 1.00%. Phytate is a strong acid that is detrimental to your calcium, iron and zinc metabolism. Not a recommendation to eat nuts. Lectins destroy two glycoproteins in your joints: N-Acetylglucosamine and N-Acetylneuraminic acid due to greatest affinity. Here, nuts are doing the same bad job as WGAs (wheat germ agglutinins). Consequently, no nuts, no bread.
The cashew is the seed of a fruit, which can be safely eaten. The difference between the cashew seed and a legume is important here. The mechanism by which the cashew seed defends itself is with the hard shell, then a skin irritant both of which are external to the seed itself. The mechanism by which legumes defend themselves are anti-nutrients which are a part of the edible portion of the food. It is not possible to separate the legume from it's poisons, where as it is trivial to separate cashews from theirs. That difference in chemical defense mechanism is what makes a legume that "looks like a nut" very dangerous, while the nut is fine.
Cashews (and the fruit attached to them) are all good to eat, just don't go crazy. The w3/w6 ratio isn't spectacular and they are particularly calorie dense, and in the case of the fruit, well it's fruit and very sugary.
Large-seeded legumes were part of the human diet long before the Neolithic agricultural revolution, as evident from archaeobotanical finds from the Mousterian layers of Kebara Cave, in Israel.
Efraim Lev, Mordechai E. Kislev, Ofer Bar-Yosef (March 2005). "Mousterian vegetal food in Kebara Cave, Mt. Carmel". Journal of Archaeological Science 32 (3): 475–484
Wouldn't it be better to sprout nuts (almonds & pecans) to neutralizes some/most of the anti-nutrients. when sprouted the nut believes that it's going to grow into a tree and enhances it's nutritional value and sprouts. Am I wrong?
I think the key issue with nuts nowadays is that we can get them shelled, ground up, and otherwise processed. They may well turn out to be a less than ideal food, but our ancestors had to do some real work to get relatively few of them. I can buy them shelled and eat enough to make myself sick (ah, those early days of going paleo!). Clearly there are unpleasant chemicals in them, but our ancestors were unlikely to get dose we can manage today.
Due to the whole Omega 6/Omega 3 ratio thing, I eat fewer nuts. Under particular circumstances, like traveling, I still see the can of raw almonds as a life saver, because it helps me avoid stuff that could be contaminated with wheat or soy.
VDawg contradicts himself. He states a selection of communities, makes the claim they live long lives, when in non-lala land plenty of meat eating communities live just as long. Why? Because they balance their diet and eat unprocessed foods. Much like the Paleo advocates.
I view the Paleo as an unprocessed foods way of life. I don't stay with their guidelines always, I drink raw milk, eat raw honey etc. But so far the Paleo has been the most convincing diet which promotes immune boosting foods and I'm talking disease reversing as well as tooth cavities vanishing. Whereas Vegan diets restrict too aggressively.
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