Sometimes it’s a Nut, but Most Times it’s Not!

Nuts-CLose-Up

This post, although timely as we enter the holiday cooking season, was prompted by a colossal fever blister outbreak I experienced last week.  Statistics state 50 – 80% of US citizens have had outbreaks of these blisters caused by one of the eight forms of the herpes virus.  I promise this isn’t going to be a medical article, but bear with me another paragraph or so!  Chicken pox, shingles, roseola, as well as what we know as “herpes” are conditions caused by this type of virus.  For some of us, this virus is always looming in our nervous system waiting for us to become ill or run down, or, as in my case last week, to eat too many nuts in one sitting.

You may already know that nuts are good for us nutritionally as they provide omega-3 fatty acids, fiber and protein to our diets.  However, one component of the protein found in nuts is the amino acid l-arginine.  Without getting into medical jargon, I’ll just state that the majority of professionals tend to think l-arginine promotes the herpes virus.  After I ate two “heavily-pecaned” pecan pie slices last week and awoke the day after with a major outbreak on my lower lip, I have to say I believe in this theory.  Another proponent to this theory is most physicians recommend a daily dose of l-lysine for those of us that are prone to fever blisters, shingles, etc.   L-lysine is an amino acid that appears to counter l-arginine in our diet.  Thus, eating more l-lysine-rich foods or supplementing with l-lysine tablets may help keep the body from becoming out of balance.

Whew!  Now on to my relevant “gardening” post!

When researching pecans, learning about the high levels of l-arginine within them, and attempting to figure out what other nuts I need to avoid this season, I came across some very interesting information about how we popularly categorize fruits, vegetables, nuts and seeds versus how scientists actually categorize them.   An acceptable label for those hard seed items we use in cooking and snacking is “culinary nuts”.  However, for botanists, the scientific categories they use, and reasons for them, are extremely diverse, detailed and technical so I will simply list a few surprise classifications I discovered, beginning with one you may already know –

Peanut – is not a true nut, but a legume.  Most gardeners may already know this as peanuts develop underground versus on trees.   Legumes in general produce pods that house more than one seed.  Beans are legumes as well as are peas.  Since the peanut has the flavor of a nut but is a legume, I can only guess these two facts were combined to form the peanut’s name.

Peanuts are Legumes

Peanuts are Legumes

Pecans, Walnuts, Almonds – are not true nuts, either!  They are botanically considered drupes.  A drupe is a type of fruit that has ample flesh surrounding a flexible shell (pit) with a seed inside.  We typically think of peaches and plums in this category for they are obviously fleshy fruits with pits/seeds inside.  However, if you take a look at how pecans, walnuts and almonds form and mature on the tree, you’ll see that they, too, begin with a fleshy outer part just as do peaches and plums.  The difference is we discard the flesh, remove the outer shell (pit) and eat the inner seeds of pecans, walnuts and almonds.  To differentiate between the fleshy and non-fleshy drupes, some call those in which we eat the seed, “dry drupes”.

Pecans

Pecans

Pecans on the Tree w/Fleshy Green Exterior

Pecans on the Tree
w/Fleshy Green Exterior

Almonds w/Fleshy Exterior

Almonds w/Fleshy Exterior

Cashew & Pistachios – are drupes as well.  An interesting aside about these culinary nuts is they are actually related to the poison ivy plant.  While peanuts are the most allergenic of culinary nuts, those who are particularly affected by poison ivy may experience an issue with these two.

Coconuts – are also drupes.  I placed the coconut in a different paragraph because what we typically consider the flesh of the coconut is actually the seed.  Take a look at the green flesh of the immature coconuts below.  Once mature, we crack the shell and indulge on the white seed.  Thus, a coconut is categorized as a dry drupe.

Immature Coconuts w/Fleshy Green Exterior

Immature Coconuts
w/Fleshy Green Exterior

Cocos_nucifera_-_Köhler–s_Medizinal-Pflanzen-187

Hazelnut – is a true nut, finally!  As are chestnuts and acorns.  A true nut has both the (thin) “flesh” and seed enclosed in a hard pod and the seed is not automatically expelled from the pod as are the seeds of legumes and drupes.  Legume pods split at maturity to release their seed and drupe pods split or rot to release their pit/seed.  Thus, to get to the seed of a true nut you’ll need a nutcracker or other device to do so – no paper shells in this category!

Hazelnuts are Without a Fleshy Exterior

Hazelnuts are Without
a Fleshy Exterior

Lastly, probably the biggest surprise to me . . .

Avocado – is a berry.  Yes, you read this correctly!  It is a berry.  I only bring this into the mix because as I was reading about drupes I thought it described the avocado to a tee. I thought I had this scientific classification stuff figured out.  Wrong!  Basically, as I mentioned far above, you have to know a lot about how a plant’s fruit is formed (from the very beginning through maturity) to be able to accurately categorize it.  For example, the seed of the avocado is actually surrounded by a very thin, hardly detectable, fleshy shell (which is a flexible but harder shell in a peach, plum, pecan, walnut etc.)  The other, thick layer of flesh of the avocado is comparable to the flesh of, say, the peach, but again, we are eating both the outer flesh and the inner “shell” of the avocado.  The seed, we toss.  Thus, having both an edible fleshy interior and edible fleshy (very thin) shell, makes the avocado a berry. 

Avocado

Avocado

Of course, berries are typically multi-seeded and the avocado has but one seed.  Technically, the avocado is a single seed berry.  I could go on about berries, which gets even more complicated as a strawberry is considered an aggregate of drupes (drupelets) and not a berry, but I think I’ll just stop for now as I’m veering far off the topic of nuts –

In closing, and back to nuts, I am providing the link below to an l-arginine/l-lysine ratio chart so that no matter how many pieces of pecan pie or other nut, legume, drupe or berry goodies you eat on Thanksgiving, you’ll have information to balance (or supplement) your diet and hopefully avoid any ill consequences of overindulging!  http://www.traditionaloven.com/tutorials/l-lysine_rich_foods.html

 

Happy Thanksgiving!

Cindy

 

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