How Nutrition Affects Our Hearing

By Meagan Rowley

Nutrition is fundamental to health, but seldom does one learn about the relationship between diet and the auditory system. Nutrition and hearing ability are, in fact, connected.

There is no specific food that will definitely cause or prevent hearing loss. Likewise, lost hearing cannot be restored through a diet change. However, new research suggests that certain nutrition patterns may actually decrease—or increase—your risk of developing hearing loss.

A 22-Year Diet Study

A Brigham and Women’s Hospital study monitored the hearing health of more than 70,000 women on various diets for 22 years. These diets included the Alternate Mediterranean Diet (AMED), Dietary Approaches to Shop Hypertension (DASH), and Alternative Healthy Eating Index-2010 (AHEI-2010). These diets favor fruits, vegetables, seeds, nuts, legumes, whole grains, seafood, poultry, and low-fat dairy. All three also advise limiting foods that are high in sodium (salt) and LDL (low-density lipoprotein) cholesterol, discouraging consumption of refined and red meats, processed foods, and sugary drinks.

Women following diets similar to the AHEI-2010, DASH, and AMED decreased their likelihoods of hearing loss by at least 30 percent, with DASH and AMED showing the greatest benefits. The researchers found that diets that prioritize fruits and vegetables with minerals like folic acid, potassium, and zinc decreased the risk of hearing loss.

Beneficial Nutrients

Other findings indicate that certain nutrients are associated with positive hearing health outcomes. Potassium—a mineral found in bananas, potatoes, and black beans—plays a large role in the way that the inner ear functions and converts sounds into signals for the brain to interpret. Regular intake can help you maintain your current level of hearing, says Sherif F. Tadros, M.D., of the International Center for Hearing and Speech Research in a Europe PubMed Central published study.

George E. Shambaugh, Jr., M.D., of the Shambaugh Hearing and Allergy Institute reports that the zinc in almonds, cashews, and dark chocolate can be an effective treatment for tinnitus, hearing ringing or buzzing without an external sound source. Magnesium is believed to combat free radicals emitted during loud noises and act as a barrier protecting inner ear hair cells.

Folic acid has also been shown to possibly slow the onset of hearing loss. Blood flow is restricted by homocysteine (an amino acid), so folic acid works to metabolize it to keep blow flow regulated. According to Jane Durga, Ph.D., of the Nestlé Research Center in Lausanne, Switzerland, because the inner ear relies on a regular flow of blood, folate is extremely important. Foods high in folic acid include spinach, broccoli, and asparagus.

Adverse Effects of Malnutrition

Conversely, malnutrition negatively affects the human body. In an examination of 2,193 participants ages 16 to 23, Susan D. Emmett, M.D., and colleagues found that malnutrition not only stunts anatomical development in children, but slows inner ear development. Malnourished children were observed as being twice as a likely to develop hearing loss as young adults compared to their well-nourished peers.

Further, the study acknowledges that that stunting often begins before birth. A malnourished woman who is pregnant or nursing is likely to pass on any deficiency she may have to her child. Hindered inner ear development in utero caused by malnutrition contributes to a higher risk of hearing loss than does malnutrition in vivo.

Diabetes Connection

Individuals with type II diabetes also are more likely to develop hearing loss than their nondiabetic counterparts, according to an National Institutes of Health-funded project by researcher Chika Horikawa, Ph.D., of Japan’s Niigata University. Subjects with prediabetes—those who have elevated blood sugar levels but not elevated enough for a diagnosis of diabetes—also have a 30 percent increased risk The study authors attribute the higher risk to damaged nerves and blood vessels of the inner ear, a consequence of having type II diabetes for an extended period of time.

Though rarely acknowledged, diet has a lot to do with the auditory system. Adding just a few foods to your daily diet and paying attention to the nutrients that your diet is missing may significantly impact hearing over the long term.

As an aspiring doctor currently studying nutrition during my undergraduate years, I understand how important it is to look at an individual's state of health from different angles and perspectives. Nutrition is vital to every aspect of health.

An HHF summer intern, Meagan Rowley is a senior on the pre-medicine track studying human nutrition at Case Western Reserve University in Cleveland.

---

A Clinical Trial for a New Drug to Protect Hearing

By Yishane Lee

The U.S. Food and Drug Administration (FDA) has approved a novel drug to protect against ototoxicity (harmfulness to hearing) due to the use of aminoglycoside antibiotics to treat severe infections. The FDA approval paves the way for a Phase I clinical trial to test whether the drug, found to be significantly protective in animals, is safe for humans.

Mature lateral line hair cells from larval zebrafish (shown with the neuromast sensory organ enlarged) serve as a platform for studying drugs and genes that modulate hair cell susceptibility to ototoxic agents.

The drug, ORC-13661, was developed by University of Washington professors Edwin Rubel, Ph.D., and David Raible, Ph.D., who are members of Hearing Health Foundation’s Scientific Advisory Board and Hearing Restoration Project, respectively, and Fred Hutchinson Cancer Research Center scientist Julian Simons, Ph.D. “While this program was not directly funded by HHF, both David and I have definitely been supported by HHF for a long time,” Rubel says. “This is a drug to prevent hearing loss that we've developed over the past 15-plus years.”

Rubel points out the drug’s two main features: “It is a brand new drug with a composition of matter patent, not one that is used for other medical purposes and being repurposed; and it is the first drug that was developed, from the get-go, to protect hair cells from ototoxic injury.”

After screening libraries of potential chemicals to see which stopped hair cell death in zebrafish lateral line system, Rubel, Raible, and team identified the best candidate and then boosted its effectiveness by tweaking its chemical structure; results were published in the Journal of Medicinal Chemistry in January 2018.

Rubel adds, “Toxicity studies in zebrafish, rats, and dogs required by the FDA show superior safety and nearly 100 percent hearing protection at all frequencies.” If the Phase I trial shows the drug is safe for humans, the next step is to test its efficacy among patients using aminoglycosides.

San Diego Tunes In to Hearing Health

By Jordan Conole

On February 11th, Hearing Health Foundation (HHF), the nation’s largest nonprofit funder of hearing and balance research, hosted a public seminar on hearing health and hearing loss in at the Central Library in Downtown San Diego.

Guests mingle before the start of presentations on hearing loss research and treatments in the Shiley Special Events Suite of the San Diego Central Library.

Event attendees included members of the public, scientists and researchers, many of whom have devoted their careers to finding a cure for hearing loss.

Ronna Hertzano, M.D., Ph.D., a surgeon at the University of Maryland Medical Center, spoke about the need for change in the way we treat hearing loss, noting, “Just as a doctor would now take a patient with elevated or slightly higher blood pressure seriously, we must do just the same with hearing.” Dr. Hertzano claimed that those who experience hearing loss oftentimes can suffer from loneliness and feelings of isolation.

According to a recent study by the National Aging Committee, more than 11% of those with some form of hearing loss suffer from depression compared to only 5% of the general public.

Dr. Harrison Lin, a scientist funded by HHF’s Emerging Research Grants program, and colleagues discovered that of the 48 million Americans who report experiencing some form of hearing loss, only about one-third of those actually seek out treatment.

Ken Knoblett, a San Diego resident who counts himself as part of that third, noticed a drastic change in his interactions with friends and family once he began to use hearing aids. “I was immediately able to be more connected to my friends and family and enjoy gatherings again. The hearing aid and treatment really changed my life for the better!”

Based on the strong connection to hearing loss and its strong emotional side effects, testing for hearing loss and treating it is the best way to combat and prevent its underlying side effects.

Hearing loss is an isolating condition for hundreds of thousands of Americans, but the scientists working for HHF hope to someday end that isolation.

Jordan Conole is a freelance journalist who covers San Diego local nonprofits and charity events in the surrounding areas. 

Get Moving to Preserve Your Hearing

By Yvonnie Phan

As 2018 begins, many Americans, motivated to improve their physical and mental wellbeing, have already made the popular New Year’s Resolution to exercise more frequently. This commitment has an additional, lesser-known benefit; exercise is proven to preserve hearing health. Engaging in physical activity with proper safety precautions can delay or prevent age-related hearing loss, or presbycusis, which affects a quarter of adults 65-74 and half of those older than 75.  

Cardiovascular exercise is vital to hearing health as one ages. A person over 50 years old without a genetic predisposition to hearing loss and who engages in cardio for 20-30 minutes five times weekly is more likely to maintain a healthy auditory system than someone with low cardiovascular activity. In a decade-long Miami University study of 1000 subjects of all ages, those over 50 with moderate-to-high cardiovascular fitness levels maintained hearing sensitivity comparable to people in their 30s, effectively delaying presbycusis.

An additional investigation from the University of Florida affirms that routine cardio provides the necessary blood flow, oxygen, and nutrients to maintain the health of important auditory systems within the cochlea. Lead author Shinichi Someya, Ph.D. explains that  “the cochlea, or inner ear, is a high-energy demanding organ.”

Stretching and yoga are healthy alternatives to cardiovascular exercise. These activities facilitate proper blood flow throughout the body and activate the muscles. While stretching or performing yoga poses, it’s important to focus on breathing to increase oxygen and blood flow. There are even yoga poses designed specifically for those with tinnitus.

The hearing health benefits of exercise can be negated by noise exposure or improper ear care, however.

Listening to audio through headphones at a loud volume can increase one’s chances of Music-Induced Hearing Loss (MIHL), as can the music played during exercise classes. Turning down the volume on your device, wearing earplugs, and giving ears time to recover from loud noises can help prevent damage to the auditory system.

Those who swim are encouraged to keep their ears dry. Moisture in the ear allows for bacteria, or even fungi and viruses, to attack the ear canal, which can lead to Swimmer’s Ear and cause temporary hearing loss. Dry ears immediately and do not insert anything, such as cotton swabs, into them.

Health professionals strongly recommend everyone incorporate exercise into their daily routine. There are many benefits in maintaining a consistent exercise regimen and we can now add hearing loss prevention to the list. Before starting a new fitness routine, consult your physician to assure the routine is safe and suitable for your health.