Why your morning cup of coffee may be harmful to your hearing

Thinking about drinking an extra-large cup of coffee to wake up after that late night at the concert? You might want to make it a decaf – especially if your hearing hasn’t fully recovered. Researchers at the McGill University Health Centre in Montreal, Quebec have discovered that daily consumption of caffeine can prevent hearing from returning to normal after exposure to loud noise.

What is Temporary Threshold Shift (TTS)

Most individuals have experienced a temporary loss of hearing or ringing in the ears after attending a loud rock concert, fireworks celebration or flying in an airplane. The common condition, known to medical professionals as Temporary Threshold Shift (TTS), occurs when the delicate hair cells of the inner ear are overworked and become fatigued. Recovery times vary from a few hours to as many as 72 hours before normal hearing returns.

What does caffeine have to do with it?

Caffeine is a natural stimulant found in coffee, tea, chocolate and many energy drinks as well as some non-prescription cold and allergy medications and pain relievers. It stimulates the central nervous system, improving circulation and focus and keeps us from feeling tired after a late night on the town. Studies indicate caffeine may reduce the risk of certain cancers, such as liver, mouth and throat as well as type 2 diabetes, Parkinson’s disease and stroke.

But when it comes to hearing health, caffeine may not be so body-friendly. According to the research, caffeine from even one cup of coffee can prevent your hearing from returning to normal after an episode of TTS. Dr. Faisal Zawawi, an otolaryngologist and member of the McGill Auditory Sciences Laboratory, said his researchers suspected certain substances hindered the body’s ability to repair hearing after an episode of TTS. They decided to test their theory on three groups of guinea pigs. In the study published in April 2016 in the Journal of the American Medical Association (JAMA) Otorhinolaryngology Head and Neck Surgery, one group was exposed to 110 decibels (dB) of sound, a level equivalent to the noise of most concerts. The other two groups of guinea pigs were also exposed to 110 dB as well as 25 mg (per kg) of caffeine (which we should note is a very large caffeine dose, and the equivalent for humans would be something like 10 espressos).

The guinea pigs exposed only to sound regained their hearing by day eight. Those who were exposed to sound and caffeine never fully regained their hearing. That led the researchers to conclude that caffeine combined with TTS can lead to permanent hearing loss.

Prevention

While most individuals recover after an episode of TTS, constant exposure to noise louder than 80 dB can cause permanent hearing loss.  

According to the Hearing Health Foundation, close to 50 million Americans have hearing loss. Of them, 26 million can attribute that loss to overexposure to excessive noise at work or play. Noise-induced hearing loss (NIHL) is one of the most common types of hearing loss and can be caused by a one-time exposure to excessive noise, such as an explosion, or occur slowly over a long period of time. Fortunately, NIHL is also the most preventable type of hearing loss.

So do you have to give up your cup of coffee to protect your hearing? Not necessarily. If you’re one of the 100 million Americans who drinks coffee on a daily basis, giving up your daily habit may not be an attractive option. Fortunately, there are other preventive measures you can take to protect your hearing:

• Limit your exposure to noisy environments. If noise at the workplace is uncomfortable, talk to your supervisor about ways to reduce the sound level. According to the National Institute on Deafness and Other Communication Disorders (NIDCD), comfortable hearing levels at work are 60 dB or less.
• Be mindful of leisure activities where noise is a factor and take steps to minimize your ears’ exposure. A shotgun blast can register as much as 165 dB and cause permanent hearing damage.
• Wear foam earplugs or headphones to minimize the decibel level. You can still cheer on your favorite sports team at the stadium, just take along ear protection when you go. The highest recorded decibel level at a sports stadium was 136.6 dB at the Seattle Seahawks CenturyLink Field in 2013.
• If you do experience an episode of TTS, avoid caffeine until your hearing recovers. While the research isn’t conclusive, play it safe. You can always resume drinking your favorite caffeinated beverage once your hearing returns to normal.
• Find a hearing professional you can trust and have your hearing checked on an annual basis. Once a baseline has been established, your hearing healthcare professional will work with you to make sure you’re hearing your best.