I just wrote and audiology paper and wanted to share it with my lactivist friends. It is nothing special but I think a few of you will find it interesting. :)
Breastfeeding’s Role in Reducing Otitis Media Induced Hearing Loss
Most new mothers have heard the advertising slogan “Breast is Best”. It is part of an advertising campaign by the federal government to increase breastfeeding rates among American mothers. Much research has been done to uncover the many benefits of breastfeeding which include reduced risk of obesity, reduced incidences of allergies, increased immune systems, and reduced risk of many types of cancer (Sears, 2011). Yet, as wonderful as breast milk is for babies, could there really be any reason to write an audiology paper about the subject? As it turns out, yes there is! Not only does breast milk have all the properties mentioned above, but it also plays a role in preventing hearing loss (Bauman, 2011). Increased immune system, a more hygienic angle for feeding, and natural genetic therapy all lead breastfed babies to have reduced rates of chronic otitis media. As chronic otitis media is a leading cause of conductive hearing loss in children, having fewer incidences of chronic otitis media leads to reduced rates of conductive hearing loss in children.
The first way in which breastfeeding reduces chronic otitis media induced hearing loss is that breastfeeding has been proven to increase a child’s immune system (Sears, 2011). Breast milk contains live cells, like those in blood. These cells contain active antibodies and anti-infective properties. As a result of these properties, breastfed babies, on average, experience fewer hospital stays, doctor’s visits, and illnesses in general. Specifically, researchers at the University of New York's School of Medicine and Biomedical Sciences found that 25% of exclusively breastfed babies had had an ear infection by six months. In comparison, 54% of formula fed babies had experienced an ear infection by six months of age. Further more, these researchers found that formula-feeding was the most significant predictor of chronic inner ear infections (Duncan, 1993).
When a child has otitis media there is almost always fluid in the middle ear. The average hearing loss in ears with fluid is 24 decibels. Thicker fluid can cause a loss, up to 45 decibels. This loss can cause significant detriment to a child’s speech development. (American Academy of Otolaryngology-Head and Neck Surgery, 2011). Therefore, as breastfeeding reduces the incidence of otitis media, it by default reduces the rates of conductive hearing loss in children.
The reduction of otitis media is not limited to the time in which the child is breastfeeding either. It has been shown that the antibodies and anti-infective properties consumed in breast milk continue to protect children against otitis media through their 5th birthdays, and possibly beyond (Duncan, 1993).
The second manner in which breastfeeding protects against otitis media induced hearing loss is that children that are breast fed are naturally held at an inclined position to feed. When the head is held tilted up the milk follows a normal path down the esophagus. However, when a baby is lying flat on his back and sucking on a bottle, formula can find its way into the eustation tubes. (See examples of common feeding positions below.) In infants the eustation tube is much shorter and is more angled. This makes it much easier for bacteria to migrate from the nose and throat up into the middle ear space (American Academy of Otolaryngology-Head and Neck Surgery, 2011). Having formula inside the eustation tubes creates a breeding ground for bacteria and leads to otitis media. (Sears, 2011). As breastfed babies are fed at an angle that is hygienic for the eustation tubes, as a group they experience fewer incidences of otitis media due to this benefit.
Examples of common bottle-feeding and breastfeeding positions:
Pictures are from stockphoto.com
The last way in which breastfeeding guards against otitis media induced hearing loss is perhaps the most exciting. In 2006 the University of Texas Medical Branch at Galveston performed a study that indentified two genes that are common in children who have chronic otitis media. These two genes generate immune proteins known as tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6). (University of Texas Medical Branch at Galveston, 2006). Beyond merely identifying the genes that make children prone to chronic otitis media, the researchers found that breast-feeding neutralized the effect of the genes. Not only that, children were found to be protected from recurrent infections even later in childhood when they were no longer breastfeeding. This is not just another example of the anti-infective properties of breastfeeding, but evidence that breastfeeding has genetically therapeutic qualities. (University of Texas Medical Branch at Galveston, 2006)
Nearly all of the articles referenced in this paper were linked on Le Leche League International’s website. http://www.llli.org/nb/nbbenefits.html. This site and organization is dedicated to promoting the benefits of breastfeeding and supporting mothers whom breastfeed or wish to breastfeed. Le Leche League International reports that despite the benefits of breasting listed above and many, many more, only 15% of American mothers are exclusively breastfeeding at 6 months, as is recommended by the American Academy of Pediatrics. ("Breastfeeding statistics," 2008) Although this number is not simply due to lack of education on the benefits of breastfeeding alone, this lack does play a role in the low rate. It is therefore the role of all medical professionals, including Audiologists and Speech Pathologists, to educate parents and potential parents on the benefits of breastfeeding as a way to reduce the risk of otitis media induced hearing loss.
The American Academy of Otolaryngology-Head and Neck Surgery (2011, November 15). Fact sheet: Chronic otitis media (middle ear infection) and hearing loss. Retrieved from http://www.entnet.org/HealthInformation/otitisMediaHearingLoss.cfm
Bauman, N. (2007, November 03). Breast-feeding reduces ear infections. Retrieved from http://hearinglosshelp.com/weblog/breast-feeding-reduces-ear-infections.php
Breastfeeding statistics . (2008, September 29). Retrieved from http://www.llli.org/cbi/bfstats03.html
Duncan, B. (1993) “Exclusive breastfeeding for at least four months protects against Otitis Media”, Pediatrics 91: 872
Sears, W. (2011, November 15). Ear infections. Retrieved from http://www.askdrsears.com/topics/childhood-illnesses/ear-infections
University of Texas Medical Branch at Galveston (2006, December 9). Breast-feeding Overcomes A Genetic Tendency Toward Ear Infections, Scientists Discover. ScienceDaily. Retrieved November 15, 2011, from http://www.sciencedaily.com¬ /releases/2006/12/061209083450.htm