Mar 21

The Nutty, Yet Irritating Family (Cashews, Pistachios and Mangoes)







At a young age I discovered that I am allergic to Pistachios. As a young adult training to be a Peace Corps Volunteer, I discovered that I am very allergic to Mangoes. What is the connection?

They are both plants in the Plant Family: Anacardiaceae. Interestingly enough so is the Cashew, yet I very rarely exhibit any reaction when eating cashews. For medical and scientific reasons that are far beyond my comprehension, all possess the toxin known as urushiol. For those of you that clicked on the link, you will also note that urushiol is also present in Poison Ivy, Poison Oak and Poison Sumac. All three of these plants are also a part of the Plant Family: Anacardiaceae.

When I think back on how I learned that I was sensitive to pistachios and mangoes, but rarely and only mildly with cashews a small amount of deduction reasoning helped create the complete picture. The oil urushiol is found in the skin of the mango and the shells of the pistachio and cashew. Given that it is near impossible that to slice a mango without exposing the fruit to the oils released from the skin, the urushoil makes contact with the fruit. Likewise, since most pistachios come in their shells, one cannot avoid touching the shell to remove the nut. The process used to remove the cashew from it’s shell is to roast the shell. Proper roasting of the shells destroys the toxin. One could surmise that pistachios are roasted differently and the presence of the shell with the nut makes for contact with the toxic oil more likely.

It was my father, with his passion for horticulture that uncovered this relationship (before the age of internet search engines) after the incident of with the mango.  The irony of this discovery and having been given nickname “Musa Dutoe” (Moses the Mango in Mandinka) from my fellow Peace Corps Volunteers is that Mangoes and Cashews grew with little effort in the Gambia in West Africa where I was stationed as a Peace Corps Volunteer in 1993-1995. While my friends gorged on mangoes, enjoyed locally shelled cashews and the soft fruit of the cashew known as a cashew apple, I stayed far away from these foods.

Whereas my father was extremely allergic to Poison Ivy, I only exhibit the standard reaction to the plant. It is the eating some of the fruit and nuts of the family Anacardiaceae that causes me so many problems. What a shame.

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  1. Stuart

    Did you know that Pistachios are also prone to spontaneous combustion. As their fat decomposes it can cause them to self heat and then self combust. Because of this have special handling and transportation requirements.

  2. Lynn

    About two years ago, at the age of 48, I made the connection that I am allergic to cashews. And cashews only. Mangoes are my favourite fruit and I buy many when they are in season – no problems. I can eat pistachios, and can shell them, no problems. However, I generally do not like the texture of nuts and have tended to avoid all nuts my entire life. Up until 2 years ago, if I did consume a cashew it was usually in the environment of a pub, the resultant vomiting was always blamed on alcohol consumption. Now I know. The symptoms are a sudden onset of hayfever like tingling, itchy mouth and within 6 – 7 minutes I am vomiting. I feel as good as new about 4 hours later. I think the symptoms are getting worse as well which is why I have suddenly made the connection in later life. Funny though, that it is cashews only and not the toxins in the shell that are mentioned here.

  3. ryan

    Oddly enough, I am highly allergic to both cashews and pistachios but not mangoes. As far as I know cashews and pistachios are my only two food allergies. I wonder why the mangoes don’t get me.

  4. Paullet

    I am also only allergic to cashews and pistachios …. but can’t sat i have ever had a mango but I am sure i have drank juice with mango….

    I dislike having this cause no one seems to realize how serious it is, always picking on me about it…
    it also makes me feel nervous every time I try something new, so many things are coming out with a cashew variety now…. cashew butter, granola bars that have them, and now they are even trying to get M&M’s with cashews…

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