A Joke It’s Not
A stand-up comedian from New York once quipped “Yesterday I went to the doctor and he said I had a nut allergy. Really. Every time I have to spend Thanksgiving with my crazy Uncle Mort, I break out in hives.”
Aargh! No more Borscht-belt humor – I promise.
But, seriously folks, we’re talking about a potentially life-threatening condition. If hives were the only symptom of tree nut allergies, I wouldn’t be writing this article.
Symptoms of tree nut allergies range from itchy skin and rash to anaphylaxis. The latter is a life-threatening condition caused by the body’s reaction to an allergen. And it can be fatal.
Most of us know someone who is allergic to insect stings or peanuts. They are the ones who often carry an adrenaline (epinephrine) injector with them at all times.
Recently, I had lunch with friends, and since we all had salads, we felt that dessert was earned and in order. (This dubious justification for eating pastries is one of the few benefits of eating “rabbit food” beforehand.)
The menu offered some seriously tempting items. In fact, it offered two of my favorites, baklava and cannoli.
Not knowing when we would happen upon such sweet delicacies again, enough was ordered for all five of us. I failed to remember that one member of our group has a tree nut allergy.
The cannoli may contain pistachios, walnuts or even hazelnuts. While the baklava can harbor walnuts, almonds and pistachios, depending upon the regional origin of the recipe.
Fortunately, my friend exercised due diligence by avoiding the consumption of all tree nuts and opted for a nut-free pastry.
Just imagine how difficult it must be for parents with a child who is allergic to tree nuts, seeds or peanuts. These food items are ubiquitous and not always apparent when ordering in a restaurant or purchasing food off the grocery store shelf.
And, concern must extend beyond just the nutmeats themselves to include oil from nuts, nut flour or even non-nut food processed with machinery that also processes nuts.
Since 2004, the FDA has required mandatory labeling of specific allergens, including wheat, eggs, fish, crustaceans, latex, peanuts, soybeans and tree nuts. Unfortunately, it doesn’t extend to many other food allergens such as mustard and sesame seeds.
Brazil is the only country, to date, that requires the inclusion of all food allergens in its labeling.
For those of us who love the many and varied flavors of tree nuts, such a condition is akin to never enjoying the pleasure of cheeses or chocolate. It robs us of a range of nature’s most delightful eating experiences.
What is in a nut that is capable of snuffing out a human life?
The actual component of a tree nut that causes an allergic reaction in some people is a specific protein.
There is a range of proteins in which the structure, often appearing under an electron microscope as tiny coiled wires, may cause an inflammatory response in some people.
Those with tree nut allergies may be sensitive to one or more types of nuts. This is particularly so when the protein structure in the nut is similar to another nut.
For example, suppose you are allergic to cashews. In that case, you may also be allergic to pistachios because the proteins are in the same family. The molecules of the allergen proteins share a similar architecture.
Whereas, if you can eat pecans with no allergic reaction, you may also be able to eat walnuts for the same reason.
As stated earlier, tree nut allergies are on the rise. But on the bright side, about 9% of those with this allergy will outgrow it.
The entire issue of tree nut allergies is complicated, so most affected people, like my friend, avoid all nuts.
What about peanuts?
There is a marked distinction between peanut allergies and tree nut allergies. That peanuts are nuts is a misconception; they are legumes; common garden peas and beans are an example of legumes.
It is important to note that there are many types of food allergies. Nut allergies are only one specific allergy. There has been a 50% increase in aggregate food allergies in children alone between 1997 and 2011. This is shocking, but efforts are underway to identify the causal factors.
Peanut and tree nut allergies have tripled between 1997 and 2008. Of the 2.5% of children in the U.S. who are allergic to peanuts, 20% will outgrow it.
That said, some 30% of those with peanut allergies are also allergic to tree nuts.
With statistics like those above, it is no small wonder that the time-tested favorite of grade-schoolers, the PB&J sandwich, * is now banned in many schools.
Making mud pies.
There is much speculation about why the western world is subject to a rise in food allergies and asthma, particularly among children. Diagnostics are improving but that would only account for a fraction of the increase.
It may come down to something that affects our health in general – poor diet, processed foods and environmental concerns.
There are also proponents of allowing children to get “down and dirty” as a technique to prevent many allergies.
Called the Hygiene Hypothesis, some researchers claim that our children are being raised in overly clean conditions. Anecdotally, it does seem that this sudden spike in allergies coincides with several decades in which children do not get outside as much as previous generations.
Those of my generation who were children in the 1950s and 1960s spent more time outdoors than kids today. Here, we had direct contact with soil, plants and pollens. And, we were encouraged to do so by our parents.
“Go outside and play. I don’t want to see you back here until dinner time.” This was not an uncommon phrase from mothers in earlier times.
In centuries previous to the twentieth, many rural children were essential to running a farm. Here there were exposure to all forms of potential allergens, including all manner of beast and fowl.
We were often sent straight to the shower or bath to remove the dirt upon returning from outdoor play. Perhaps that physical contact with the matrices of nature as a child may have boosted our immune systems.
This hygienically sterile learning and playing environment of modern children is a recent cultural phenomenon. Many children today live, play and learn in a protective bubble.
The Hygiene Hypothesis may also explain the fact that children who are gradually exposed to the peanut protein can sometimes be gradually acclimatized to peanuts and peanut products.
What about wild nuts?
It is late autumn here in Appalachia, and many people are gathering and drying black walnuts and hickory nuts. These nutmeats are prized for their taste and textures and often end up in holiday cookies, cakes and fudge.
So, where do these “wild” nuts figure into the spectrum of tree nut allergies?
The black walnut, a native tree of Eastern North America, is technically not a nut. It falls into the category of fruit or drupes.
Checking numerous sources, I could not find a correlation between the proteins found in black walnuts and tree nut allergies. Beyond, of course, the known allergic effects of black walnut pollen and contact dermatitis.
That said, common sense strongly suggests that if you have a tree nut allergy, you should consult with an allergist before consuming any black walnut product.
The impressive thing about the black walnut is its ability to exert a certain amount of control over its immediate environment. Juglone is a chemical compound emitted by the black walnut tree that retards the growth of nearby plants and is fatal to most insect herbivores.
Juglone can also cause a severe rash in humans and is toxic when ingested. The nutmeat is edible as the toxin is limited to the leaves, fruit, and roots.
Surprisingly, a recently popular product of the black walnut tree, walnut syrup, does not cause an allergic reaction, at least so far.
Hickory nuts are listed among the tree nuts containing allergens. So, please make sure anyone that you share your hickory confections with is aware of this. Those who are allergic to hickory nuts often have cross-reactivity to pecans and English walnuts.
Shelled hickory nuts can also cause pollinosis in allergic people, resulting in hay fever, rhinitis, watery eyes and sneezing.
We are fast approaching the holiday season, where foods containing nuts are popular items. Please be aware of the people, especially children, among your family and friends who have tree nut allergies.
When entertaining, it is our responsibility to protect those we care about from this life-threatening condition.
And, if you are fortunate enough not to have a tree nut allergy, then “nuts to you” – in a good way this season.
* PB&J is Peanut Butter and Jelly, just in the far-fetched case you didn’t know.