July 22, 2010

By Brian Bujdos

Many reports, especially in the last year, have brought attention to the potential harmful effects of nasal sprays, gels, and swabs that contain zinc. It was only last summer that the FDA warned consumers that intranasal cold remedies that contain zinc may cause loss of smell.

More specifically, the FDA suggested to Americans that they should steer clear of three Zicam products, all of which were voluntarily pulled from the market. Well over 100 users of the products experienced a loss of smell – referred to as anosmia.

The latest study was performed by a University of California professor that has a history of involvement with zinc cold-relieving medications. His study analyzed 25 people who complained of loss of smell at his clinic after using a nasal product with zinc gluconate – the ingredient in question.

The study utilized a nine-point system called the Bradford Hill Criteria to determine whether the zinc products actually caused the loss of smell – which ranged from temporary to permanent. The researchers said that each of the nine criteria pointed to zinc as the culprit for the patients’ loss of smell.

Others in the medical field state that although zinc is closely tied to loss of smell, absolute scientific proof is hard to produce due to the fact that upper respiratory infections, sinus problems and the common cold are the main cause of loss of smell. Of course, the use of zinc nasal products often coincides with these medical conditions.

There are also very few studies that indicate zinc is an effective treatment for colds or other symptoms. A study in 2001 declared that zinc sulfate nasal spray helped reduce cold symptoms on day one, but not on any other days. The study also reported only mild adverse effects for the treatment. The 2001 study was randomized, while the California study above was not.

Although Zicam removed all of its zinc nasal products from the shelves, hundreds of zinc nasal products are available through homeopathic sources. Americans spend $3 billion annually on homeopathic medicines, and one survey estimated that about 40 percent of Americans utilize “alternative” sources to treat their allergies.

The challenge with homeopathic/alternative medications is that they are not regulated by the FDA, they may or may not have an expiration date, and they may or may not contain what their manufacturers or labels claim. The California professor who released his study in the July issue of the Archives of Otolaryngology (head and neck surgery) states that the FDA needs to more closely regulate homeopathic medications in order to protect consumers who use zinc-containing, and other, products.

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