Cortex Eucommiae Ulmoidis & Latex Allergy

Townsend Letter for Doctors and Patients, Jan, 2001 by Bob Flaws

In an article titled "Allergic to Latex? That's Probably Not All," Sara Latta writes that "[allergic] reactions to latex proteins have risen sharply over the last 15 years." [1] Commercial latex comes from Hevea brasiliensis, the Rubbertree. This tree is from the family Euphorbiaceae and now grows in tropical regions around the world. Natural rubber comes from the elastomers "which consists of solids suspended in a milky fluid, called latex, that circulates in the inner portions of the bark of many tropical and subtropical trees and shrubs." [2] (Italics mine) As the authors of the Encyclopedia Britannica go on to say, other trees, shrubs, and herbaceous plants produce rubber, just not as efficiently as Hevea brasiliensis. According to Diana Swift, in an article titled "Kiwis Can Caution Against Latex Allergy;" 1-6.7% of the general population is allergic to latex, while an additional 20% are latex sensitive. Among health professionals, latex sensitivity and/or allergy ranges from 3-17%. [3] While the majori ty of latex allergy sufferers are women, [4] children are also especially at risk, as are people with allergic rhinitis or other allergies. [5] In fact, people with food allergies, especially allergies to bananas, kiwi fruit, avocados, chestnuts, and stone fruits, such as cherries and plums, run a 10-fold risk of developing latex sensitivity according to Yale University anesthesiologist Dr. Jonathan Katz. [6] Within Hevea brasiliensis, it is any of 12 defensive proteins that cause allergies in humans. Again, as Steve Kagen, MD, director of the Kagen Allergy Clinic in Appleton, Wisconsin, points out, these proteins are "produced by a variety of other plants as well." [7] These proteins cause an immune system reactions mediated by antibody immunoglobulin E (IgE).

The Rubbertree is not considered a medicinal within standard professional Chinese medicine. However, Eucommia ulmoides is, and one of this tree's common English names is Hardy Rubbertree. [8] This is due to two facts. First, it is the only type of "rubbertree" which can grow in such temperate climates as England and the US. Secondly, its sap does contain' natural rubber elastomers or latex. As the authors of the Bushnell Park Website write, "At one time, people thought that the long, pointed leaves of this tree might be harvested to produce commercial rubber, but the amount of latex in them is very small." [9] Perhaps, those people should have looked at the bark and not the leaves. In Chinese medicine, the part of Eucommia ulmoides which is used medicinally is the bark. This is referred to as Cortex Eucommiae Ulmoidis (Du Zhong) within the Western practice of Chinese medicine. This medicinal comes in flattened pieces of grey-brown bark which have been cut into small strips almost all the way but not quite th rough. These small strips are held together by a stretchy, silver-white substance at the base of the bark which looks like rubber and does contain latex. In fact, the way Chinese pharmacists determine good quality Cortex Eucommiae Ulmoidis (Du Zhong) is by seeing how much and how elastic this springy, rubbery substance is. Hence the peculiar manner of cutting Du Zhong within the Chinese pharmaceutical trade is both a way of determining quality and a way of insuring maximum dissolution of this medicinal's active ingredients when decocted in water or tinctured in alcohol. This is the only Chinese medicinal of which I know that is prepared for sale and dispensation in this way.

Within Chinese medicine, Cortex Eucommiae Ulmoidis (Du Zhong) is categorized as a yang supplement which nourishes liver blood, invigorates kidney yang, moves the qi and quickens the blood, strengthens the sinews and bones, secures the fetus and stops (low back) pain. According to the authors of an online advertisement for Du Zhong Cha (Cortex Eucommiae Tea), a decoction of this medicinal is "the drink needed by the busy working man, it does not contain caffiene and will not cause side effect[s]." [10] (Italics mine) While it is true that, within the Chinese medical literature, there are no particular side effects and few contraindications listed for this medicinal, [11] to say that it is free from side effects may not be correct, especially with Western patients. I was first introduced to the idea that Cortex Eucommiae Ulmoidis (Du Zhong) contains latex and, therefore, may be allergenic in a certain percentage of patients several years ago by the Belgium Chinese medical teacher and author, Francois Ramakers. At the time, I did not give this new piece of information much credence, since, to the best of my knowledge, I had never had a patient who had a bad reaction to this medicinal. However, Ramakers assured me that he and other European Chinese medical practitioners had.

The issue of multiple allergic sensitivities is a growing concern within the practice of medicine in the West. It appears that the incidence of allergies of all kinds is growing. More than 50 million Americans suffer from various types of allergies. That means one out of five! One out of every 11 office visits to a doctor is for some sort of allergy. Somewhere between 17-25% of the US population sufferers from allergic rhinitis. In fact, allergic rhinitis is the single most common disease experienced by Americans. [12] It is now also a well-known fact that people who are allergic to a wide variety of foods also have a higher incidence of allergy to latex. According to Sara Latta, people who are allergic to any of the following foods have a higher than average probability of also being allergic to latex since all contain proteins similar to the allergenic ones in latex: avocados, bananas, chestnuts, kiwis, raw potatoes, tomatoes, stone fruits, such as peaches, plums, cherries, and apricots, hazelnuts, melons, celery, carrots, apples, pears, papayas, almonds, peanuts, ginger, oregano, sage, dill, peppers, citrus fruits, coconuts, pineapples, mangos, figs, passion fruit, and ugli fruit. [13] Typical allergic responses to the foods on this list include an itchy or tingling feeling in the mouth, hives, difficulty breathing, headache, or gastrointestinal symptoms. Therefore, I now believe that Cortex Eucommiae Ulmoidis (Du Zhong) should only be prescribed with care to patients with either multiple food allergies (especially to any of the foods on the above list) or multiple chemical sensitivities (especially sensitivity or allergy to latex). Latta also suggests two other ways of determining if one might be allergic to latex, and, if either of these two are positive, I also recommend avoiding or only using Cortex Eucommiae Ulmoidis (Du Zhong) with care.