Zinc: Cold Cure or Commodity?

Chances are that if you've suffered from the sniffles or a sore throat within the past year, you've also heard about a new remedy that's being sold as the "cure" to what many believe to be an incurable ailment, the common cold. Zinc is being talked about everywhere -- on television news programs, radio and the Internet, and from medical schools to corner drugstores -- in new, unexpected, and astonishing ways. The metal and nutrient has always served a variety of functions, including widespread usage as a dietary supplement, but not until recently have people developed a fascination with its relationship to the common cold. Now, with little to go on besides word of mouth, millions of consumers are clearing drugstore shelves of any and all zinc products, especially the lozenges they've heard billed as a "cure." But is it safe to assume that any zinc product is as good as another? And what about the medical profession's reaction to such a discovery as mind-boggling as a cure to the common cold? If zinc is to be considered the miracle-drug of the 21st-century, why has news of its efficacy only just begun to reach the population at large?

People have good reason to be excited about the prospect of a viable and dependable remedy for the common cold. While a cold is usually little more than a nuisance, for some it can mean substantial economic loss (in terms of time lost from work) or complications involving more serious viral infections. And while remedies range from chicken soup to vitamin C to antibiotics, there is no foolproof way to prevent or reduce the sneezing, coughing, stuffy or runny nose, and general malaise that accompany a cold. This is due to the fact that the common cold is not caused by a singular entity, but is instead a constellation of symptoms caused by any one of a number of different kinds of viruses. Rhinoviruses cause between sixty- and seventy-percent of all colds, but since there are almost 200 rhinovirus varieties, or serotypes, it is still impossible to prevent "catching" a cold. Because of the immense diversity of cold-causing viruses, the possibility of a common cold vaccine is also effectively ruled out. So why the sudden faith in zinc lozenges? Is the word "cure" misleading millions of consumers, or are there scientific facts behind all the hype over zinc? What exactly is the science behind such a seemingly unthinkable product as the common cold cure?

Click here for an animated gif image of one of the 200 serotypes of rhinovirus.

While scientists had already investigated the antiviral properties of zinc, until the early-1980s their inquiries lay largely outside the realm of common cold research. Since research done in the 1930s on rhinoviruses concluded that a cure for the common cold was impossible, and newer promising areas of scientific inquiry have eclipsed older ones, few scientists have devoted much energy to studying zinc's ability to alleviate upper respiratory ailments. Within the last couple decades, however, numerous studies around the world have documented the ability of solution zinc ions (Zn2+) in lozenge form to drastically reduce both the duration and severity of all cold symptoms. So what acted as the catalyst to re-start scientific interest in the common cold? Scientific discoveries do not exist in a vacuum. Rather, the scientific method relies on collaboration among researchers as well as a build-up of knowledge and methods that can be reproduced. It is only in this way that reliable conclusions can be reached. This is no less true in the case of research into zinc and the common cold. Indeed, zinc lozenges have appeared on the cold remedy market as an overnight sensation, but the research prior to their appearance has taken anything but one night. However, while many have contributed to the success of zinc lozenges, the persistance of one man has acted as a constant catalyst in the search for answers, and has eventually led to a patent in his name for a cure to the common cold.

Eby's Enterprise

In June of 1979, four months after his daughter was diagnosed with acute T-cell lymphocytic leukemia, George A. Eby stumbled into the search for a "cure" to the common cold. Three-year-old Karen Eby was diagnosed in February and immediately started on intense schedule of chemotherapy. Her doctors were hopeful, but cautious in their expectation of recovery; they certainly didn't expect her response to be as immediate as it was. After only a month, her doctor reported Karen's bone marrow leukemic blast count at zero, as well as a sudden proliferation of new healthy red blood cells. Her rapid progress astonished oncologist Paul Zeltzer to such an extent that he sought an explanation for it outside of his own treatment, and suggested to Karen's father George that "perhaps one of those enormous vitamin and mineral supplements you've been giving her interacted beneficially with our chemotherapy." If indeed a supplement was aiding Karen's recovery, Zeltzer feared that ceasing to administer it would cause her condition to deteriorate again, so he suggested that Eby investigate any proven medicinal properties of the various dietary supplements he and his wife were giving Karen.

Eby had no background in science or medicine, but with a daughter sick he accepted the challenge of identifying the mystery nutrient that was boosting Karen's immune system. A month of library research led him to narrow his focus to zinc, after a study of the clinical literature revealed a 1974 study that had found that zinc ions inhibit the replication of rhinoviruses. (Korant et.al.) Rhinoviruses are a factor in the type of leukemia Eby's daughter suffered from, but are known primarily as the chief infectious agents of the common cold. Since Karen was being treated with immunosuppressive chemotherapy, she was prone to suffer from particularly severe colds as well, so alleviating cold symptoms become another priority for Eby. He continued giving Karen zinc, vitamin C and other supplements known to boost resistance to viral infections, but due to her immunosuppressed condition, nothing seemed to have a noticeable effect.

It would take a moment of serendipity for George Eby to get the clue he needed to venture into years of research that has ultimately ended up in what he calls "the world's only patent" for a "cure" to the common cold. In June, Karen Eby came down with a particularly severe cold. She tried first to swallow, then to chew the 50-mg zinc gluconate tablet her parents gave her, but was too weak and exhausted to do either. She fell asleep with the tablet half-chewed, and it was allowed to dissolve in her mouth. Two hours later, she astonished her parents by getting up to say she felt much better. All her cold symptoms were gone, and did not return. Dietary supplements are meant to be swallowed, so why was it that the child's cold symptoms disappeared only when she let the tablet dissolve in her mouth, instead of swallowing it? And if the zinc tablet did have anti-viral properties, were they specific to zinc gluconate or would any zinc compound produce the same results? Eby knew that answers to questions like these had the potential to help not only his daughter, but countless others. . .in fact, everyone who had ever suffered from what is perhaps the world's most frustrating ailment -- the common cold. What Eby might not have known then, but must surely know now, is how in any kind of scientific inquiry, questions lead not only to answers, but also to countless more questions. Indeed, after Eby's initial discovery of the possibility that zinc might play a role in alleviating the symptoms of the common cold, so many new questions were raised that it would take years of research even to come to any tentative conclusions. It was not until 1996 -- after seventeen years of collaborative and competitive research -- that Eby secured the patent for and began to mass-produce zinc lozenges.

Eby's initial discovery, as well as his continued success administering the zinc tablets in informal studies using his own family and friends, led to the first formal investigation of the effects of zinc lozenges on the common cold. In 1983, Eby led a group of Austin, Texas physicians and scientists in a controlled study which tested zinc gluconate lozenges on an 80-person sample. (Eby et.al.) The researchers found that, without exception, the symptoms of those who took zinc disappeared on average seven days faster than those who were given placebos. A confirming British study in 1987 came up with similar results. However, both studies used unsweetened lozenges. Before lozenges could be marketed successfully to the public, researchers would have to determine the exact science behind their efficacy. Why had the lozenges used in various studies had different rates of success, and why had some actually worsened cold symptoms? It turns out that the concept of zinc ion availability is one crucial element that is needed to understand why some lozenges succeeded in alleviating cold symptoms, while others did not.

ZIA is defined as the potential for zinc ion absorption via the biologically-closed electrical circuit of the mouth and nose. Metallic ions such as Zn2+ are capable of traveling long distances in a number of the body's systems via what are called biologically closed electric circuits (BCECs). One usually associates electrical activity with biology only in relation to the nervous system, in which nerves transmit electric "messages" to control most of the body's functions. However, as B.E.W. Nordenstrom has shown, electrical potentials can also be found in virtually all the muscles and tissues of the human body. In the case of the mouth-nose circuit, metallic ions attach themselves to and change the charge of capillary walls, providing a pathway for positively-charged ions to travel along. (Source: http://www.coldcure.com/) This, in essence, in how solution zinc ions work to alleviate common cold symptoms. Not only must they have a ZIA of at least 100 to be effective, they must also be dissolved under the tongue in order to interact with infected upper respiratory processes. Once this information was known, only one problem remained.

The question of creating an effective yet also pleasant-tasting zinc lozenge was more complicated than one might expect it to be. According to Eby, clinical research was slowed by studies done without adequate knowledge of zinc ion availability (ZIA) values and compound reactions, as well as by overzealous manufacturers who jumped at the chance to market a product without full knowledge of how lozenges worked. As more studies added their sometimes conflicting results to the initial successes of zinc lozenge research, corporations vied to be the first to market a "cure" to the common cold. But companies soon found out that like certain combinations of chemical compounds, capitalism and science don't mix as easily as they'd hoped they would. Lozenges had to be made to taste pleasant without sacrificing effectiveness, because there would be no point to a lozenge if a negative reaction between the sweeteners and zinc compound negated the ZIA level and hence, the medical benefits of the lozenge.

Using data gathered from both successful and unsuccessful zinc lozenge studies over the last fifteen years, as well as information on compound stability constants, Eby found that of all zinc compounds, only zinc gluconate and zinc acetate (when combined with sugars) left ZIA values high enough to be medically viable and didn't change the pH of the lozenge, which would also negate any beneficial effects. After the 1996 Cleveland Clinic study (Mossad, et.al.), Eby's patent went into effect and he (as well as anyone who suffers from colds) had found his "cure." But the question remains: are zinc lozenges really a cure for the common cold? If one thinks of a cure as something along the lines of a vaccine, a drug that will prevent the disease from occurring, then lozenges cannot very well be considered one. But if one thinks of a cure in terms of a foolproof treatment, then it is safe to say that perhaps zinc lozenges are as close to a cure as we'll ever get. At the same time, we once said that about chicken soup.

Bibliography

Eby, George. Handbook for Curing the Common Cold - The Zinc Lozenge Story. (Austin, TX: George Eby Research, 1994).

Eby, George, et.al., "Reduction in Duration of Common Colds by Zinc Gluconate Lozenges in a Double-Blind Study," Antimicrobial Agents and Chemotherapy 25 (Jan. 1984): 20-24.

Farr, Barry M., et.al., "Two Randomized Controlled Trials of Zinc Gluconate Lozenge Therapy of Experimentally Induced Rhinovirus Colds," Antimicrobial Agents and Chemotherapy 31 (Aug. 1987): 1183-1187.

Korant, B.D. et.al., "Zinc ions inhibit replication of rhinoviruses," Nature 248 (12 April 1974): 588-590.

Mossad, B.S., et.al., "Zinc gluconate Lozenge for Treating the Common Cold - A Randomized, Double-Blind, Placebo-Controlled Study," Annals of Internal Medicine 125 (1996): 81-88.

Zinc Acetate Lozenges -- the World's Only Patented Cure for Common Colds

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