The Role of Diet in Tinnitus and Hearing Health
A healthy diet and lifestyle are our best weapons in the prevention of cardiovascular disease, but what about their impact on preserving hearing health and lessening the impact of tinnitus? To explore this topic, the ATA talked to Christopher Spankovich, PhD, an expert in this field.
Joy Onozuka (JO): We all understand the importance of eating a well-balanced healthy diet to optimize our long-term physical and mental health. Based on your research, is there sufficient evidence to propose a healthy hearing diet?
Christopher Spankovich (CS): Our diets do indeed influence our hearing health similar to how our diets influence our overall health and risk for chronic disease. Yet, the relationship of diet and specific nutrients in susceptibility to hearing loss and tinnitus (as with other acquired disorders) is complicated and influenced by an array of factors (which influence each other) such as our genetics, environment (including noise exposure), physical activity, lifestyle, and of course our overall health status (both physical and mental). For example, individuals with type 2 diabetes have significantly increased odds of hearing loss. The cascade of biochemical effects created by diabetes can lead to glycation, protein and lipid dysfunction, nitric oxide and glutathione dysregulation, glutamate excitotoxicity, and microangiopathy. It is also likely that an individual who develops type 2 diabetes has dietary and physical activity factors that exacerbate risk for further pathology.
Most of our information on specific nutrients and risk for acquired hearing loss comes from animal models, primarily rodents. This presents a limitation, as animals do not necessarily share the same bioavailability of nutrients; species can vary in regard to how they metabolize, utilize, and excrete nutrients. Let’s consider vitamin C. Vitamin C is an essential nutrient in humans (dietary required) and has numerous roles in our cells: it serves as an enzyme for synthesis of neurotransmitter and neuropeptide hormones, is a cofactor in the hydroxylation and maturation of collagen (healing of musculoskeletal tissue), is an important water-soluble antioxidant, and helps to keep vitamin E in a reduced state. Most rodents (with the exception of guinea pigs) endogenously synthesize vitamin C, meaning they do not require a dietary source. This is all related to a specific gene that encodes L-gulonolactone oxidase(GULO); primates (whichinclude humans) had amutation in the genethat encodes GULO about 30 × 106 years ago, so we need vitamin C from exogenous sources (e.g., food). Therefore, a rat model may not be the best to look at dietary vitamin C and hearing outcomes, since their cells make vitamin C on their own.
In general, research has focused on nutrients with antioxidant, anti-inflammatory, or anti-ischemic properties. Perhaps the simplest dietary change that appears to affect susceptibility to hearing loss is caloric intake. Simply restricting caloric intake can significantly reduce evidence of hearing loss and lead to increased longevity in a number of rodent models, but evidence in primates is still under study. Caloric restriction studies often reduce overall calorie intake by approximately 30 percent compared to normal intake but maintain adequate nutrient intake to avoid malnutrition.
Other dietary factors that have been considered include macronutrient intake (fats, carbohydrates, protein) and various micronutrients (e.g., B vitamins, vitamins C and E) and minerals(e.g., magnesium, zinc, selenium). Numerous epidemiological studies have demonstrated relationships between specific nutrients and hearing health. Nevertheless, examining single nutrients is not without limitations, namely, existence of interactions among nutrients that create biochemical and statistical collinearities. In addition to epidemiological studies examining population-level relationships, several case-control studies in humans have examined dietary cholesterol changes, folic acid supplementation, vitamin B12 supplementation, and antioxidant supplementations. Many of these studies have shown positive results but had caveats (for reviews, see Spankovich, 2015, and Spankovich & Le Prell, 2020). For example, a folic acid fortification study was completed in the Netherlands that showed some decreased risk for hearing loss, but the study was completed at a time when foods were not fortified in the Netherlands and baseline folate levels were about half of those found in the U.S. population (Durga et al. 2007). Thus, we find another factor, adequate intake of nutrients or role of nutritional deficiency. It should be noted that many foods are fortified, meaning extra nutrients are added. For example, vitamin D in milk. The first food fortified was salt with iodine.
In the United States, true dietary deficiencies in key nutrients are less common, much in part because of accessibility, fortification, and supplements. However, certain nutrients are commonly considered inadequately consumed, including vitamins B6, B12, C, D, iron, and magnesium. A perhaps greater issue in the United States is excessive intake of unhealthy calorie-dense foods that lack a variety of nutrients, which leads to a person being not only overweight but also malnourished.
JO: What are your thoughts on food and supplements?
CP: We must consider the source of nutrients, food versus supplement. First, how food is prepared and sourced is a consideration. A question I am frequently asked is whether organic food is more nutritious than conventional. In short, there is minimal difference in nutritional content, but it can vary by specific foods. However, organic foods may have other advantages such as lower levels of pesticide residue.
Supplements are a different story. Most standard vitamin supplements are nature-identical synthetic. Back to our friend vitamin C. The most popular form of vitamin C is ascorbic acid, which is the same as naturally occurring vitamin C. Synthetic and food-derived vitamin C is chemically identical. However, fruits and vegetables that contain vitamin C are rich in other micronutrients, phytochemicals, and dietary fiber. The presence of these other factors may influence bioavailability compared to the synthetic supplement form. For vitamin C specifically, this is not believed to be a meaningful difference in humans, but for other vitamins, such as vitamin E, food sources allow significantly improved bioavailability compared to supplements. Another consideration is the starting material for synthetic supplements is commonly coal tar, petroleum, or acetylene gas that goes through chemical processes to duplicate the structure of the isolated vitamin. Other supplements that are not strictly synthetic can be food based (e.g., vegetable oils) or cultured through raw materials such as yeast/algae or bacterial fermentation. It is important to note dietary supplements are not regulated by the U.S. Food and Drug Administration and therefore the quality of products can vary tremendously. Also, studies on supplements for chronic disease overall do not show much benefit and some show possible harmful consequences.
Rather than focusing on specific nutrients, a likely more effective approach is to focus on dietary quality. Eating a healthy diet will include the nutrients described above, as well as an array of other chemicals important to health. Our group previously examined dietary quality through a measure called the Healthy Eating Index (HEI). The HEI is a measure of how well a diet conforms to the recommended dietary guidelines of the U.S. Department of Agriculture (USDA). The HEI has gone through several revisions through the years as the USDA guidelines are updated. In brief, the HEI provides a score of 0 to 100 in regard to quality of diet; higher scores indicate a diet meets USDA recommendations. Putting aside whether you think USDA guidelines are correct or not, there is a relationship between a higher HEI and lower (better) hearing thresholds (Spankovich & Le Prell 2013, 2014). More recently, Curhan et al. (2018) showed that adherence to the Mediterranean diet and Dietary Approaches to Stop Hypertension (DASH) diet reduced risk for hearing loss.
What do I recommend to patients? Eat a healthy diet and exercise, and run any changes by your primary care physician. What is a healthy diet? Eat more vegetables, more fruit, and good sources of fat, such as fish, nuts, and seeds. Eat less processed foods, less fried foods, and less high-glycemic-index foods (e.g., foods with added sugar), and less red meat. These suggestions are in general consistent with the DASH diet and Mediterranean diet mentioned earlier. If you eat healthy and exercise, a multivitamin is generally unnecessary. On the contrary, a multivitamin will not magically correct a poor diet or lifestyle.
JO: Does the type of hearing loss matter?
CS: Possibly. This is where a supplement may prove to be beneficial. In general, a healthy diet will likely be adequate in diminishing risk for hearing loss as much as it can. Where additional supplements may come into play is when there is a challenge to the system. For example, numerous studies have shown that animals with diets supplemented with antioxidants (e.g., vitamin E) can reduce risk for noise-induced hearing loss. However, the effects of antioxidants on age-related hearing loss have been less clear, with contradictory reports of protection and no protection.
JO: Hearing loss has been ranked as the fifth leading cause of years lived with disability, ahead of other chronic conditions such as diabetes and dementia. Given that, should audiologists and doctors be discussing dietary strategies that might enhance long-term hearing health with their patients?
CS: Audiologists could benefit from more training in basic biochemistry, system physiology, pharmacology, and nutrition. That training would be helpful for audiologists to feel more confident in discussing factors beyond the ear. The truth is physicians need more training in nutrition also. Unfortunately, most medical schools provide limited training on diet and nutrition.
The ear is not separate from the rest of the body. What we eat and our physical and mental health have important implications for hearing, tinnitus, and balance.
JO: Why are people with diabetes more prone to hearing loss and tinnitus?
CS: Diabetes causes a cascade of biochemical consequences that can lead to increased risk of hearing loss. To reduce risk, persons with diabetes should following the ABCs of diabetes management, eat healthy, exercise, and follow healthy hearing guidelines. This includes getting your hearing checked and monitoring it over time and using hearing protection and hearing conservation practices (turning down volume) to reduce risk of noise-induced hearing loss.
JO: Though there are no foods that cause tinnitus, many people find that such things as salt, caffeine, and alcohol trigger or aggravate their tinnitus. What are your thoughts on that?
CS: Foods or beverages that cause spikes in tinnitus often cause only transient spikes. The majority of work examining salt has focused on Ménière’s disease (MD), but the evidence of salt influencing Ménière’s disease is fairly low (some patients with MD are salt sensitive others not so much), though eating a low-sodium diet is not a bad thing. When it comes to caffeine and alcohol, the key is moderation. Again, a cup of coffee or a glass of wine (not the whole bottle) is not likely going to lead to sustained changes in tinnitus perception. For people who do experience a spike in tinnitus with coffee or alcohol, they need to make a choice. I can enjoy my delicious cup of coffee in the morning and deal with the tinnitus spike or can skip the coffee and not have the spike.
JO: Vitamins and minerals play a role in hearing health. However, there’s no evidence that supplements have any benefit for reducing tinnitus, which is why the American Academy of Otolaryngology — Head and Neck Surgery Foundation wrote in their tinnitus practice guidelines (2014) that “clinicians should not recommend Ginkgo biloba, melatonin, zinc, or other dietary supplements for treating patients with persistent, bothersome tinnitus.” Despite that, patients are sometimes told to take lipoflavonoids because they “might” help. As someone who has worked with tinnitus patients and researched the role of diet on hearing health, what would you like patients to know?
CS: The placebo effect related to tinnitus is considerable, with reports as high as 40 percent. The placebo effect is when an agent with no active substance creates a therapeutic effect due to psychophysiological factors.
Another consideration is the lack of an objective measure of tinnitus: we cannot objectively measure a change in the tinnitus signal; rather, we are dependent on the patient’s self-reported perception and reaction. Of supplements, Ginkgo biloba has probably been studied the most. A review of the literature will show contradictory findings, some studies showing benefit and others not. The variation in efficacy can be related to the type of Ginkgo biloba, dosage levels, and having appropriate randomization and placebo-based controls in place. Namely, the Ginkgo biloba extract EGb 761 has been demonstrated to have some efficacy compared to placebo; however, the quality of this evidence is low and hence the recommendation from AAO-HNS. Higher-quality research is needed. Also, a concern with Ginkgo is potential platelet inhibitory actions of the herb that can impair coagulation and thus concern for patients on anticoagulation medications. In addition, there is no evidence that Ginkgo biloba cures tinnitus, though some patients report reduced severity. There are no randomized controlled trials of lipoflavonoids for tinnitus published in the peer-reviewed literature. I therefore do not recommend them to my patients.
I do recommend that my patients eat a healthy diet and exercise. They should consult their primary care physician when making changes to their diet and exercise regime. Exercise-wise, you should do what is within your ability, but be more active.
Will diet and exercise cure tinnitus? No. Will it hurt it? Not likely. If anything, eating healthy and exercising can improve overall health and well-being, improve sleep, and improve the ability of a person to effectively habituate to tinnitus. I rarely see a tinnitus patient who is a vegan marathon-running yoga fanatic. I see many who are overweight, eat below average quality diet, are on multiple medications for high blood pressure/cholesterol/diabetes, and lead sedentary lifestyles. Tinnitus can be perceived as an alarming and bothersome percept; let it be an alarm, rather, a wake-up call to start leading a healthier life and taking care of yourself.
Hippocrates said over 2,000 years ago, “Our food should be our medicine. Our medicine should be our food.” That remains true today. Also, Mama Spankovich said while I was growing up, “Eat your fruit and vegetables and go outside and play.” Pretty good advice also.
Christopher Spankovich is an associate professor and vice chair of research for the Department of Otolaryngology and Communicative Sciences at the University of Mississippi Medical Center. He obtained his MPH from Emory University, AuD from Rush University, and PhD from Vanderbilt University. Spankovich is a clinician-scientist with a translational research program focused on prevention of acquired forms of hearing loss, tinnitus, and sound sensitivity. His research has been funded by industry, federal, and professional bodies. He has published over 60 articles and book chapters (41 in peer-reviewed journals) and has given over 60 national and international presentations. Dr. Spankovich continues to practice clinically with special interest in tinnitus, sound sensitivity, ototoxicity, hearing conservation, and advanced diagnostics. He holds adjunct faculty status with Salus University and Nova Southeastern University and serves as an associate editor for Audiology Today and the International Journal of Audiology. He was recently elected to the AAA Board of Directors. He also provides consultant services for medicolegal cases.
Curhan et al. (2018). Adherence to Healthful Dietary Patterns is Associated with Lower Risk of Hearing Loss in Women, J Nutr., 148 (6), p944-951.
Durga et al. (2007). Effects of Folic Acid Supplementation on Hearing in Older Adults: A Randomized, Controlled Trial. Ann Intern Med 146, p1-9.
Spankovich & Le Prell (2013). Healthy Diets, Healthy Hearing: National Health and Nutrition Examination Survey, 1999-2002. Int J. Audiol 52, p369-376.
Spankovich & Le Prell (2014). Association Between Dietary Quality, Noise, and Hearing: Data from the National Health and Nutrition Examination Survey, 1999-2002. Int J. Audiol 53 (11), p796-809.
Spankovich & Le Prell. (2020). The role of diet in vulnerability to noise-induced cochlear injury and hearing loss, J. Acoust Soc Am, 146 (5).
Spankovich. (2015). The Role of Nutrition in Healthy Hearing: Human Evidence. In J. Miller, C. Le Prell, and L. Rybak (Eds). Free Radicals in ENT Pathology, p111-128.