High Sierra Topix

Question:

I have a friend who is a city arborist. He knows a bit about plants as well as trees. He told me that it was possible to build up a relative immunity to poison ivy by ingesting the leaves of the plant in small doses over time. Is this true?

Answer:

Back in April 1987 a study on ingesting poison ivy to develop immunity was reported in the Archives of Dermatology. The report said it didn't work. But cases of severe reactions in the mouth of people who have tried a nibble of poison ivy are well documented. The future may bring a pill that decreases sensitivity to poison ivy, oak, and sumac, and the pill may be derived from the plants, but no doctor I have ever talked to recommends eating poison ivy, no matter how small the bite.

Many of us in the U.S. have had a traumatic run in with poison ivy or Poison Oak(on the west coast) at some point or another. I am only mildly allergic to poison Ivy but that doesn’t mean I was immune to it’s reign of terror when I unknowingly brought it home to my highly allergic wife on my jacket. Developing an immunity to poison ivy would be life-changing for some and at least very helpful for the majority of us. Poison Ivy(Toxicodendron radicans), Poison Oak(Toxicodendron diversilobum) and Poison Sumac(Toxicodendron vernix) are all species in the genus Toxicodendron and the information in this article generally applies to all these plant.

There are many anecdotal reports of people eating poison ivy and developing immunity. I went in search of as much information on the topic as possible. I wanted to know how poison ivy affects us and what is the best way, if any to develop a better immunity to it’s affects on the body. This article contains a summary of what I found.

How Many People Are Allergic to Poison Ivy and Poison Oak
According to americanskin.org roughly 85% of people are allergic to urushiol, the irritating compound in poison ivy and 10%-15% of people are highly allergic. When it comes to an individual’s reaction it’s somewhat more complicated because people can develop sensitivity over time and some people even decrease sensitivity over time. So the way that you react to poison ivy now may not be the same in a few years or decades. From my personal experience I have noticed that especially for people who have never or rarely come into contact with poison ivy, it sometimes takes a few interactions before they react, and that first reaction could be very bad. The moral of the story is if you have touched poison ivy a few times and seem to be immune don’t take a dare to roll it in, or rub it all over your face, you might regret it.

How Poison Ivy and Poison Oak Affect the Body
Believe it or not poison ivy does not actually directly cause the rash that you see when you come into contact with it. That rash is caused by an allergic reaction to the urushiol oil contained in the plant. An allergic reaction starts when your body identifies a foreign invader, in this case urushiol. Then our bodies produce antibodies which produce histamine. Histamine is helpful against invaders of our body because it expands blood vessels in the area which allows our immune system to better access and defeat the foreign invaders. The problem occurs when too much histamine is produced, this is an allergic reaction and this is the case with poison ivy. Too much histamine can cause rash and swelling and in some cases actually does damage to the area instead of just fighting off the invaders. So what really takes place during an allergic poison ivy reaction is that our body over-reacts and ends up damaging itself in the process. Poison ivy has evolved a way to trick the immune systems of 85% of people into damaging themselves with their own defense mechanisms. In reality our bodies do not need to react to urushiol oil and this non-reaction is what happens in the bodies of the lucky few who do not have noticeable reactions to poison ivy, poison oak, or poison sumac.

Is It Possible to Develop an Immunity to Poison Ivy?
The definition of the word “immunity” is “the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells”. Since poison ivy is not an infection or toxin you can’t become immune to it, but this word has still become a generally acceptable term to describe becoming non-sensitive to poison ivy, so I’ll continue to use it throughout this article. In regards to the coveted poison ivy immunity there is not a lot of evidence on the topic but this artice from WebMD says that it might be possible to develop an immunity through a series of small exposures over time. Giving a patient small exposures of an allergen over time is a common way to train the body to not over-react when facing those allergens, this method is sometimes called immunotherapy or sensitivity treatment. keep in mind this process is done to very specific guidelines by a doctor.

Is Eating Poison Ivy Safe?
Your instincts are correct, eating poison ivy is very dangerous. I have heard that if you eat poison ivy your mucous protects the skin inside your mouth and throat so that you don’t have a reaction. Although there potentially might be some truth to this, there are so many things that could go wrong. Many things like alcohol,smoke or certain foods can decrease mouth mucous, so the protection would be gone, a leaf could get stuck in the throat and work its way through the mucous. or you might be extra sensitive and your mucous isn’t enough to protect you.

My Experiment Eating Poison Ivy
I know I just spent the last paragraph telling you how stupid it is to eat poison ivy, but there was a time that i did eat small amounts of poison ivy every few months over the course of a few years. I wrapped the poison ivy in Violet or Yard Plantain leaves so that it wouldn’t come in contact with my throat. I didn’t have any bad reactions in my throat, but I also didn’t become immune, I have had nearly the exact same reaction since I was a kid, this period of time eating leaves, didn’t help. But there are examples of people who have eaten poison ivy and had the expected bad reaction, so I’m still urging readers not to be one of those people.

Conclusion
The conclusion is that This topic is not simple. There are stories of people decreasing and increasing sensitivity over the course of multiple exposures at different points in their lives. How sensitive an individual is seems to be due to multiple factors such as genetics, exposures, and environment. The facts we have are that there is no solid proof yet that eating poison ivy is beneficial in any way and we do have solid proof that eating poison ivy can be very dangerous. So clearly the best thing to do is not to attempt to eat poison ivy.

If You Must
If you’ve still got your heart set on eating poison ivy you can try a homeopathic remedy.Two products available are Natrabio Poison Oak/Poison Ivy and Boericke & Tafel – Oral Ivy. These products are probably diluted to the point that they don’t even contain any urushiol anymore, but hey they might be worth a try. Please leave any comment with your experiences eating poison ivy or homeopathic remedy or being smart and deciding not to eat poison ivy.

Abstract

Twenty-one adults, highly sensitive to urushiol, the allergen in poison oak/ivy, ingested up to 300 mg of urushiol over three to six months. A control group received placebo capsules. The study was done double blind to evaluate changes in patch test reactivity to urushiol, altered reactivity to an unrelated contract sensitizer, side effects, and duration of hyposensitization. A significant number of subjects in the experimental group (15/21) became hyposensitized. Such hyposensitization was not seen in the control group (2/12), and the difference between groups was significant. No change in reactivity to an unrelated contact sensitizer occurred in subjects hyposensitized to urushiol, suggesting antigen specificity. Retesting up to three months after completion of the protocol indicated that subjects remained hyposensitized without a "rebound" effect during the time. Side effects, detected by questionnaire, were limited to vesicular and urticarial rashes and pruritus ani in 18 of 21 test subjects.

"...vesicular and urticarial rashes and pruritus ani in 18 of 21 test subjects."

...the question still remains whether it makes any sense to try this yourself....
One line from the abstract posted above does jump off the page though:

"...vesicular and urticarial rashes and pruritus ani in 18 of 21 test subjects." That translates to skin blisters, skin redness, and an itchy bunghole in 86% of the subjects.

A couple leaves and Tide pod or two, I'm sure it'll all work out just fine. Make a smoothie out it if you're feeling adventurous. Try it at home. Test it on the kids

Hopefully I will never eat poison oak. Luckily I am immune to the stuff.