Xylitol, the naturally occurring polyol widely used as a sugar substitute in foods and confections, is proving to be a potent inhibitor of pathogens associated with otitis media, sinusitis, and upper respiratory infections.
A growing body of research and clinical experience suggests that xylitol can be used both prophylactically and therapeutically for these common conditions, potentially obviating the need for antibiotics and antihistamines.
According to Lon H. Jones, DO, of the department of family medicine, Texas Tech University Medical School, the vast majority of patients with the related problems of otitis, nasopharyngeal infections, and bronchitis can be greatly helped through routine washing of the nasopharynx with a xylitol solution.
Dr. Jones recently received a patent for an intranasal xylitol spray he developed after routinely using xylitol washes in his clinic. He became interested in xylitol, found naturally in several types of fruit including plums and berries, when Finnish researchers first showed that the substance had antibacterial properties and could prevent tooth decay.
URIs: Common Problems, On the Rise
In aggregate, problems falling under the heading of Upper Respiratory Infections (URIs) are among the most common presenting complaints to primary care physicians, and they are related to the similarly increasing problems of asthma and allergic disorders. The National Center for Health Statistics and the Centers for Disease Control indicate that both otitis media and asthma incidence have been increasing by 5 to 6% per year since the early 1970s. Otitis media, sinusitis and bronchitis are major drivers of antibiotic overuse and emergence of resistant pathogens.
Dr. Jones believes otitis media is simply the otic manifestation of the same process leading to sinusitis and bronchitis. The problems begin when pathogens like Streptococcus pneumoniae colonize the nasopharynx. In some people, the bacteria extend down the Eustachian canal, ultimately resulting in otitis media. In others, the bacteria enter the ostiomeatal complex to cause sinus infections. The same bacteria can cause bronchitis in susceptible people.
“The nasopharynx appears to be the central nidus where both the infectious and the allergic processes have their origin,” said Dr. Jones.
Impaired Clearance Mechanisms
Mucociliary clearance is the primary means of removing pathogens, pollutants and irritants from the respiratory tract. Unfortunately, many factors in contemporary life can impair this process. Cigarette smoke and air pollutants are toxic to the respiratory endothelial cells bearing the cilia.
But it is also important to realize that most upper respiratory conditions begin in the fall, after the first cold spells. The problems arise not so much from the cold itself, as from heating systems. Central heating dries the air, making mucus thicker, drier and harder for the ciliary system to clear. This is a major contributor to upper respiratory congestion and infection.
Consider the incidence of otitis among Native American populations in Alaska. According to health care workers working in Alaskan Native communities, otitis media and chronic suppurative otitis were largely unknown in these communities, prior to the 1970’s, when most Alaskan natives lived in their traditional ways. Later, as more indigenous Alaskans began to live in a manner similar to populations in the “Lower 48″—a transition that included housing with central heating—these problems became increasingly common. Today, Alaskan natives have the highest incidence of otitis media and suppurative otitis in the US.
“Going from a winter dwelling where the relative humidity is close to 100% to a home where it is closer to 20% was apparently too much for many of these people who had otherwise adapted to their environment in a healthy way,” hypothesized Dr. Jones. Other factors certainly contributed, including smoking, a movement away from breastfeeding, and a transition from outdoor work to close-quartered indoor work where bacteria are more easily spread.
When the accumulation of pathogens, allergens and environmental irritants overloads the mucociliary clearance mechanism, mast cells begin to release histamine and tryptase. Histamine stimulates an opening of the proximal venules, leading to an extravasation of fluid, and a cascade of immune signaling molecules. “The simple way to look at it is that the tryptase is the soap, and the histamine turns on the water for nasopharyngeal washing. In the respiratory tract, the solution to pollution is dilution,” said Dr. Jones.
The Problem with Antihistamines
This histamine-triggered process produces symptoms of rhinorrhea and membrane swelling, but it is important to realize that this is essentially a normal physiologic process, the body’s default self-cleansing mechanism once the initial ciliary clearance system is incapacitated.
The advent of antihistamines nearly 60 years ago reflected the medical community’s increasing awareness of the central role histamine played in many conditions. Antihistamines certainly provided a quick way to quell annoying symptoms; to their credit, they do temporarily facilitate the drainage of the sinuses and Eustachian tubes.
Antihistamines are perceived as safe, and they are so widely available over-the-counter, that most people hardly consider them “drugs.” In many respects, though, use of antihistamines is much like shooting the messenger.
“For more than twenty-five years we have been systematically turning off this normal, defensive self-cleansing process, and at the same time we have experienced close to a three-fold increase in the problems originating in the nasopharynx and upper respiratory tract,” said Dr. Jones. “The cost of treating ear infections in 1990 was estimated at between $3–4 billion, and the numbers have only increased since then. The cost of asthma hit $5.8 billion in 1994, and has risen further over the last decade.”
Rather than prescribing drugs that inhibit a natural self-cleansing process, Dr. Jones believes physicians would better serve their patients by helping to facilitate that process.
Xylitol and Ear Infections
Xylitol found widespread use as a sugar substitute beginning in the late 1970s. By the early 1990’s, evidence began to accrue that it reduced tooth decay compared with sucrose, fructose and other common dietary sugars (Trahan L. Int Dent J. 1995; 45(1 Suppl 1): 77–92).
Later, researchers at the University Hospital of Oulu, Finland, published a series of studies indicating that regular consumption of xylitol in syrups and chewing gum could reduce the incidence of ear infections (Uhari M, et al. Pediatrics. 1998; 102(4 Pt 1): 879–884. Uhari M, et al. BMJ. 1996 Nov 9; 313(7066): 1180–1184). These studies involved more than 800 young children in daycare settings. Those children regularly receiving xylitol in any form had marked reductions in both the number of antibiotic prescriptions and the mean number of days on antibiotics.
In studying possible mechanisms, the Finnish team concluded that alpha streptococci are unable to metabolize xylitol. The alpha streptococci include Streptococcus mutans, the principal bacterium involved in tooth decay, and S. pneumoniae, one of the most common nasopharyngeal pathogens. In the presence of xylitol, these bacteria are also less able to adhere to host tissue. A cell culture study looking specifically at nasal pathogens showed that a 5% solution of xylitol reduced the adherence of S. pneumoniae by 68%, and Haemophilus influenzae by 50% (Kontiokari T, et al. Antimicrob Agents Chemother. 1995; 39(8): 1820–1823. Kontiokari T, et al. J Antimicrob Chemother. 1998; 41(5): 563–565).
Dr. Jones, deeply concerned about antibiotic overuse, not to mention the incessant rise in otitis and URIs, had been trying to find better ways to treat these conditions when he found out about the Finnish studies. It seemed to him that intranasal xylitol washes might make a positive impact.
The concept of nasal washing is hardly new. Many patients with chronic URIs regularly use some sort of nasal spray, usually a saline preparation of some sort. Saline solutions are effective at cleaning the nasopharynx. The problem is, high saline concentrations inhibit or even paralyze ciliary movements and also inhibit the activity of naturally occurring antimicrobial substances in the airway surface fluid (Boek WM, et al. Laryngoscope. 1999; 109(3): 396–399).
Experiments with hyperosmolar mannitol solutions in the 1980s showed that they are effective for clearing the nasopharynx without inducing ciliary paralysis caused by salt solutions. However, mannitol is fairly difficult to obtain and no commercial nasal wash product based on mannitol ever emerged. Xylitol, widely available for food industry use, was a better choice.
Joseph Zabner, MD, and colleagues at the departments of internal medicine and pediatrics, University of Iowa tested a 5% near isotonic solution of xylitol, sprayed intranasally four times per day in 21 normal individuals. After only four days, these patients showed measurably decreased counts of coagulase negative Staphylococci. He and his colleagues have suggested that this approach may be helpful to people with cystic fibrosis because it lowers the saline content of the airway surface fluid and allows the innate antibacterial properties of that fluid to work more effectively (Zabner J, et al. Proc Natl Acad Sci. 2000; 10; 97(21): 11614–11619). They attribute the benefit exclusively to the osmotic properties of the xylitol. Dr. Jones contends, based on the Finnish studies, that xylitol has inherent and clinically significant antibacterial properties.
Dr. Jones developed and patented an intranasal spray containing an 11% solution of xylitol with 0.65% saline that stimulates the natural processes for cleansing the nasopharynx. Not long after he began using and teaching parents how to administer the xylitol nasal washes, word began to spread among parents of young children in his community. He soon had many young patients with recurrent URIs and episodes of otitis media.
He followed a group of ten of them very closely for one year. “The parents reported a total of 43 ear infections in the five months prior to my seeing them, an incidence of 0.86 a month. Over the average of eleven months follow-up the parents reported a total of only 7 ear infections, an incidence 0.06 per month.”
He recently licensed the patent for production of a commercially available product called Xlear (pronounced, “Clear”). While he believes the strongest effect of this product is its direct inhibitory effect on intranasal organisms, it also has a high enough osmolality to produce the osmotic effects observed in the Zabner study.
In his own practice, Dr. Jones has found that 90% of his patients with otitis can be cleared up with the intranasal xylitol spray alone. Regular use of the product after clearance of the acute phase can greatly reduce recurrences. “Rampant use of antibiotics, antihistamines and decongestants is a huge problem, and rather than helping to solve the problem, it is contributing to the problem. The best way to prevent otitis is to keep the nasopharynx clear, not to keep treating these children with antihistamines and antibiotics.”
Further information on intranasal xylitol can be found on Dr. Jones’ website, www.nasal-xylitol.com. Information on the Xlear product, along with an exhaustive list of scientific references supporting intranasal xylitol washes can be found at: www.xlear.com.
