Hearing Loss – An Earful of Hidden Causes
Most of us think of hearing -loss as a normal and inevitable part of growing old. But in less developed societies where the problem of environmental noise is less acute, the elderly often experience little or no reduction in hearing. In our society, increasing numbers of teenagers, young adults and those in the prime of life are experiencing varying degrees of hearing loss.
Ear damage has less to do with aging than a mixture of environmental pollution, dietary factors, the side effects of powerful drugs used to treat unrelated conditions and possibly even the result of depressed immune function. In the search for viral causes for hearing loss, we have all but ignored the possibility that much of it may be caused by simple bad habits: bad societal habits, which permit increasingly elevated noise levels, bad eating habits and bad medicine practised by some of our doctors. As such, much of what we call “idiopathic” hearing loss (where the cause isn’t known) can be prevented, simply and cheaply.
Sensorineural hearing loss
Sensorineural hearing loss (SNHL) or nerve deafness, is the result of dysfunction or damage to the inner ear. It may be congenital or acquired, stable or progressive (N Eng J Med, 1993, 329: 1092-1102). The most common form of hearing loss is age related, and there is no treatment to halt or reverse progression once it has begun. SNHL is often described as idiopathic and consequently most treatments are applied on a suck-it-and-see basis. But in many, possibly most, cases the idiopathic label reflects the failure of both doctors and victims to do their detective work.
The most perplexing form of SNHL is sudden hearing loss, which can develop within 24 hours and involve one or both ears. It is generally thought to be the result of disease or viral infection (JAMA, 1994; 272: 611-6) or linked with vascular problems, but nobody is really sure. Proceeding on the assumption that the cause is viral, many doctors prescribe just-in-case treatment with steroids—with 30 to 60 per cent success (Arch Otolaryngol, 1980; 106: 772-6). Nevertheless, steroids can cause the very problem that doctors are trying to cure (see box, p 1).
MRI scanning is sometimes used to look for abnormalities, but opinion is divided as to whether it finds anything useful often enough to justify subjecting patients to the stress and trauma associated with this procedure (Otol Head Neck Surg, 1997; 116: 153-6). What’s more, negative MRI findings cannot conclusively rule out the presence of damage at the cochlear level (Magn Reson Imaging, 1995; 13: 387-91). In one study, only 18.75 per cent of those scanned were found to have significant pathologic conditions causing their hearing loss (Otol Head Neck Surg, 1997; 116:153-6).
Since the damage cannot be repaired, those who experience hearing loss are often offered instruments to enhance sound—hearing aids and, in some cases, cochlear implants. Hearing aids amplify sound which is then conducted by air or bone to the ear; cochlear implants are more complex electronic pros-theses implanted into the cochlea (the spiral shaped chamber in the inner ear which receives and transmits
sound to the hearing centres of the brain). These implants translate sound energy into coded electrical signals that bypass the non-functioning or absent cochlear hair cells or axons of the cochlear nerve. The signal is sent directly to the brain—in theory, restoring the sensation of sound.
The components of a cochlear implant which lie inside and outside the ear are connected either on top of the skin (transcutaneous) or through the skin (percutaneous). With the percutaneous route there are increased problems such as infection and pedestal damage. With both routes, there is wound breakdown, requiring removal of the device, in between 0.6 per cent and 1.0 per cent of cases (Ann Otol Rhin Laryngol, 1991; 100:131-6).
Having an implant means exposing yourself to. the risks common to most surgical procedures (such as those of general anesthetic), but there are also the unique risks that are influenced by the design of the device, individual anatomy and surgical technique and competence. Complications arise in approximately 5 per cent of adult cases and 10 per cent of children’s cases. No deaths have been attributed to the surgery, but facial palsy and infection have been reported. Repeat surgery due to the device moving, coming out or failing occurs in around 5 per cent of cases.
Tinnitus
As yet there are no medical cures for tinnitus. Some doctors will offer chronic sufferers a device which masks tinnitus by substituting a different sound. This is available in several forms and is said to “relieve” 58-65 per cent of tinnitus—but usually only while the person is wearing the device. Sometimes a hearing aid will produce the same effect by amplifying other sounds to a degree which masks the tinnitus. A better way is to investigate lifestyle and environment.
Tinnitus may be a “warning bell” going off in your head. Diseases such as diabetes and arthritis, thought by some to be related to immune system dysfunction, can cause tinnitus. Hypersensitivity to salicylates (aspirin is the most common example) may be another cause. A large number of common foods contain salicylates (see box, p 4), and a side effect of aspirin consumption is ringing in the ears. (Nevertheless, be aware that aspirin substitutes such as ibuprofen have also been associated with tinnitus)._ Research has shown that removing salicylates from the diet can improve or cure tinnitus (Am J Otol, 1989; 10: 256; AADA News, 1987; 5:10). Toxic overload of lead or aluminium which contributes to immune-system problems may also cause tinnitus (Townsend Letter for Doctors, Feb/Mar, 1985; P Yannik and JG Clark, Tinnitus and its Management, Charles C Thomas, 1984).
One side effect of tinnitus is stress, and some chronic sufferers become depressed. Certain tricyclic antidepressants, however, such as imipramine (Tofranil), actually cause tinnitus.
Middle ear infection
Otitis media (earache, or infection of the middle ear) is the most common pedi-atric complaint in the US and indeed the rest of the world (Ann Otol Rhin Laryngol, 1980; 3 pt 2 suppl 68: 5-6). It is estimated that by the age of 3, two-thirds of children will have had one or more episodes of acute otitis media. Any hearing loss associated with ear infections is usually mild and temporary. In spite of decades of convincing medical evidence that antibiotic therapy is often inappropriate, many doctors still use this as a first line of treatment.
Some justify this action by focusing on the supposed (though not proven) long-term effects of middle ear infection: burst ear drums, hearing loss and thus language and developmental delays. Many a parent presented with these “facts” might feel compelled to agree to a course, or two or three, of antibiotics.
Overall, the medical literature concludes that, except in cases where symptoms such as pain, discharge and the like are severe, there is no significant differences between antibiotic and non-antibiotic therapies, incision in the ear drum, incision with antibiotics or antibiotics alone.
Children who are not given antibiotics have fewer recurrences compared with those who were given drugs (Lancet, 1981; ii: 883-7). What’s more, recent research shows that to prevent one child from experiencing pain two to seven days after leaving the doctor’s surgery, 17 children would need to be treated with antibiotics (BMJ, 1997; 314:1526-29).
Another study showed that while antibiotics may eliminate bacteria, they do not eliminate middle ear fluid and thus pain (TTK Jung, et al in Recent Advances in Otitis Media wiih Effusion, DJ Lirn, et al (eds), Philadelphia: BC Decker, 1984).
This fluid is sometimes called glue ear and grommets—to drain the ear—are still routinely recommended. It has been demonstrated that the insertion of grommets will clear up 100 per cent of cases within six weeks. But we need to pay attention to the long-term picture. Five years on, 60 per cent of children with grommets will have had more than one repeat operation. More importantly, if left alone, 75 per cent of cases of glue ear resolve themselves within five years. The figure rises to 95 per cent by seven years (Pulse, June 8,1991).
Nevertheless, in one-third of cases surgeons immediately decide to operate during the first consultation without further assessment. Glue ear continues to be the most common operation for children.
Besides being unnecessary, the insertion of grommets poses serious risks. These include tynipansclerosis (hardening of the ear drum), chronic perforation and cholesteatoma (a middle ear cyst). Despite the continued enthusiasm for this operation, since 1993, the British Medical Journal has advised “a very restrictive policy regarding the insertion of grommets” (January 2, 1993). “In some—perhaps most—cases [glue ear] may be a normal reaction to an upper respiratory tract infection,” said a BMJ editorial. “Surgical intervention would therefore be unjustified.” The BMJ’s position may be behind the recent decline in the number of operations in UK. Their number peaked in the 1980s and has now fallen by 12.6 per cent, according to an analysis of health care technologies (J Epidemiol and Com Health, 1995; 49: 234-7).
Surgery is usually recommended on the basis that glue ear will cause permanent hearing loss and cause speech delay and learning difficulties. Nevertheless, Effective Health Care, the bulletin funded by the Department of Health (November 1992), said there was no real evidence for this point of view. While nearly half of all 3 year olds may suffer from glue ear, only 5 per cent will have hearing difficulties in both ears lasting for at least three months (Pediatrics, 1994; 93: 353-63).
Glue ear is strongly associated with childhood allergies. London’s Royal National Throat, Nose and Ear Hospital reports that it monitored more than 200 children aged between 3 and 8 suffering from chronic or recurrent glue ear (Lancet, January 2,1993). More than 80 per cent were found to be suffering from rhinitis (inflammation of the mucous membranes in the nose); 35 per cent from asthma; and 20 per cent from eczema. When these children’s allergies were treated, their hearing improved. In the same issue, the journal noted that 10 years ago, a Derbyshire hospital also made the link between glue ear and hypersensitivity in 36 out of 89 children being treated.
Ear wax
Another area of concern is accumulation of ear wax. Often it is recommended that the child have his or her ears syringed. Syringing is usually done because of complaints of hearing loss, though for those with SNHL it is unlikely to help and may cause damage. Wax is a normal secretion, necessary to protect the ears. Indeed, swimmers who constantly use cotton swabs to remove ear wax are the ones most likely to end up with ear infections, known as “swimmer’s ear”. Irrigation to remove ear wax can cause damage to the sensitive lining of the external ear canal and leave it open to infections such as Pseudomonas otitis, an invasive disease which can progress to underlying soft tissue, cartilage, blood vessels or bone (Am J Med, 1981; 71: 603-14).
If ear wax is a problem, it is generally better to have it gently sucked out after softening with natural oils {olive or almond). In clinical trials most special preparations such as Crumol and Xerumenex fared little better, and on occasion even worse, than these simple, natural oils (J Laryngol Otol, 1970; 84: 1055-64; Drug Ther Bull 1971; 9: 15-16; Br J Clin Pract, 1973; 27: 454-5). Major complications such as perforation of the ear drum occur in one in a thousand procedures (BMJ, 1990; 301:1251-3).
The dietary connection
Apart from paying greater attention to level of noise you are exposed to each day there is good evidence that watching what you eat may play a large part in protecting your ears. High fat and cholesterol consumption may increase your tendency toward high blood cholesterol levels and this in turn may cause hearing impairment by reducing the flow of oxygen and nutrients to the inner ear (J Int Acad Metabology, 1975; 4: 38-42; Lancet, 1986; i: 121-3). There are several studies to show that when fats are restricted in the diet, symptoms such as vertigo, tinnitus, and hearing loss improve and can sometimes disappear altogether (Laryngoscope, 1988; 98: 165-9; South MedJ, 1981; 74: 1194-7).
The same is true for high sugar consumption, which can promote a kind of reactive hypoglycemia (sudden drop in blood sugar) and a consequent release of adrenaline, which can constrict blood vessels and affect hearing (Am Audiol Soc, 1976; 2: 15-18; Arch Otol, 1968; 87: 129). In one study of patients with Meniere’s syndrome (a disorder which affects ears and eyes), nearly 75 per cent of those who were placed on a low-carbohydrate, high-protein diet found improvements in symptoms such as vertigo, tinnitus and hearing loss (Ann Otol Rhinol Laryngol, 1981; 90 (6 pt 1) 615-18). These results have been demonstrated elsewhere (South Med J, 1981; 74: 1194-7).
In one controlled experimental study, 10 adult patients with confirmed sen-sorineural hearing loss (cochlear origin) followed a treatment programme, which included the use of distilled drinking water, reduced acid ash foods (meats and grains), increased alkaline ash foods (fruits and vegetables), reduced saturated fats, sugars and sodium, and an increase in whole foods. All of the patients reported significant improvement in hearing, symptoms of tinnitus and vertigo. Hearing improvement was also confirmed by objective hearing tests (J Appl Nutri, 1988; 40(2): 75-84).
Sidebar: What causes hearing loss
Disease
- Hearing loss at any age can be caused by: measles, mumps and chickenpox, especially if accompanied by a high fever; bacterial meningitis; Lyme disease; aplastic anemia; multiple sclerosis; vascular disease.
Certain conditions
- Premature babies (weighing less than 1500 g / 3.3 lbs), especially those who have been on ventilation for five days or more, may be at increased risk.
- Hyperbilirubinemia (excess bilirubin, the blood chemical which is normally broken down by the liver) requiring transfusion may also result in hearing loss.
Injury or noise
- A blow to the head or exposure to excessive noise can damage the internal structure of the ear.
Medical treatment
- Aminoglycosides such as gentamycin (either in multiple courses or in combination with loop diuretics) as well as other antibiotics such as vancomycin and streptomycin.
- Calcium channel blockers.
- Oral contraceptives and HRT.
- Anesthetics such as that used in epidurals.
- Chemotherapy such as Cisplatin or Carboplatin (platinum).
- Interferon.
- Labyrinthotomy (surgery to correct vertigo).
- Hemodialysis.
Birth defects
- Hearing can be damaged as the result of disease toxoplasmosis, rubella, syphilis, cytomegalovirus or herpes contracted by the mother before birth.
Heredity
- Inherited characteristics can make one susceptible to disease and defects to the ear and hearing system.
Age
- Hearing may occasionally diminish as a natural part of ageing.
Sidebar: SHL – the autoimmune connection
Interferon a protein produced when the body is infected with a virus exerts a powerful immunosuppressant effect of which hearing loss is one of the major side effects (Lancet, 1994; 343: 1134-5). Now, researchers, looking at this from another angle, speculate that sudden hearing loss (SHL) may be the result of autoimmune dysfunction (Audiol, 1995; 34: 89-102; Auris Nausus Larynx, 1995; 22: 53-8).
Another study showed that nearly 40 per cent of those with SHL had autoantibodies against the inner ear (Mol Cell Biochem, 1995; 146: 157-63).Cogan syndrome, which involves damage to the ears and the eyes, can be successfully treated if caught early one of the few treatable causes of deafness. While its causes remain unknown, it is also thought to be an autoimmune disease (J Am Board Fam Pract, 1993; 6: 577-81. There is research to show that Meniere’s disease (which also causes progressive deafness) may be triggered by immune system damage (Laryngoscope, 1993; 103: 1027-34).
In spite of this, there are currently no tests which can show whether hearing loss is the result of autoimmune dysfunction.
Sidebar: Environmental pollution
Our own bad habits and environmental noise pollution can cause hearing loss. In Australia, Dr Eric Le Page is predicting an epidemic of hearing loss in young people (Lancet, 1994; 344: 675). Using the otoacoustic emission test, which he says is far superior to conventional testing, he surveyed 6000 individuals from newborns to pensioners. He says that young people’s ears are aging three times faster than the ears of their parents; the ears of today’s average 15 year old are as damaged as the average 45 year old’s. Within the next 10 years, 51 per cent of men and 15 per cent of women will complain of impaired hearing. In 20 years’ time, he predicts those proportions will rise to 78 per cent and 25 per cent, respectively (the present levels are 30 per cent and 10 per cent, respectively).
Why are more men than women affected? The reason, says Dr Le Page, is “that whole macho thing” of guns, headbanging, loud music and a higher likelihood of head injuries. Also more men than women work in noisy industries such as construction, transport, coal mining.
Sidebar: Alternatives
Hearing loss can often be prevented and alleviated through simple dietary and environmental changes.
Breastfeed. The cheapest and most effective health insurance around. Babies who are breastfed for more than a year don’t seem to suffer from ear infections. Early bottle feeding is linked to recurrent otitis media, whereas longer breastfeeding (for at least six months) has demonstrated a protective effect (Acta Paed Scand, 1982; 71: 567-71). Another study found that children with middle ear infection had been breastfed for 8.6 months, while those in the study group without the condition had been breastfed for 13.7 months (East African Med J, 1993; 70: 623-3).Breastfeeding won’t guarantee that your child will never have an ear ache, but recovery may be more complete and more swift if you do. Breast milk contains copious amounts of gamma linolenic acid, which converts to prostaglandins, offering powerful anti inflammatory properties (Med Hypoth, 1984; 13: 161).
Nutrition. Cut down or cut out fats and sugars which can alter your vascular system and have a knock on effect on your hearing. Food additives such as sulphites and monosodium glutamate (MSG) can provoke ear ache. Try taking molybdenum to counter sulphite allergy and B6 for MSG allergy (J Orthomolec Psychiat, 1984; 105-10; Biochem Biophys Res Commun, 1981; 100: 972-77).
Investigate allergies. Ear ache is more than twice as common in allergic children than non allergic children (Laryngoscope, 1967; 77: 636). Cow’s milk, cocoa, cane sugar, cola, grains, citrus, eggs and nuts are the most common culprits, according to one study of 1000 patients (F Speer, Food Allergy, PSG Publishing Co, 1983). Allergy to salicylates may also be a cause (Am J Otol, 1989; 10: 256) The problem may be countered by avoiding aspirin and most herbs, spices and nuts, most fruits (except bananas, peeled pears, mangoes, pomegranates and papayas), most vegetables (except cabbage, Brussels sprouts, bean sprouts, celery, leeks, lettuce and peas), potato skins but not potatoes themselves, caffeine, fruit juices, alcohol and yeast rich foods such as Marmite.
Assess your environment. Airborne allergens such as house dust, tobacco smoke, animal hair and fungus spores have all been linked to ear infections (J Allergy Clin Immunol, May 1984). Lead and aluminium toxicity have also been associated with hearing loss.
Supplements. The cochlear needs vitamin A to stay healthy and functioning well (Arch Otorhinol 1978; 124: 379-82). Supplementation can improve hearing loss and tinnitus (Arch Otolaryngol 1951; May: 515-26. Combined with vitamin E it may be more effective (Acta Vitaminnol Enzymol, 1985; 7 Suppl: 85-92). Extra vitamin D may also reverse hearing loss (Otolaryngol Head Neck Surg, 1985; 93(3): 313-21; J Laryngol Otol, 1983; 97: 405-20).
Deficiencies in calcium, iron, magnesium, zinc, potassium and sodium have all been associated with symptoms of hearing loss and tinnitus.
Homeopathy. Pulsatilla can be helpful for middle ear infection (J AM Inst Homeop, 1986; 79: 3-4; Allgemeine Homeopathische Zeitung, 1985; 230: 89). Other remedies include Chenopodium for exposure to loud noise and Causticum for build up of ear wax; Phosphorus, China, Aconite, Arnica or Gelsemium can be used to treat deafness, depending on constitutional type.
Osteopathy or chiropractic. Occasionally recurrent ear ache can be caused by a mechanical problem at the top of the neck (Manuelle Medizin, 1987; 25: 5-10).
Stress management. Apart from lifestyle modifications, stress management and relaxation may be a more positive way to deal with the side effects of tinnitus. There is evidence that hypnotherapy can be helpful (J Laryngol Otol, 1996; 110: 117-20).
- This article first appeared in the October 1997 (Volume 8 Number 7) edition of What Doctors Don’t Tell You.
