Your Daily Coffee Consumption Could Be Making You Deaf, Says Science

This article originally appeared on VICE UK

Coffee's nice, isn't it? Smells like the house creaking awake sometime after sunrise on one of those postcard-perfect mornings. Smells like the big breakfast your dad used to make on a Sunday. Or, hey, maybe it smells like the creeping sense of anxiety that sets in with the realization you're about 40 minutes away from missing that deadline. Perhaps it smells like the stale tar at the back of your throat reminding you that you won't be able to tell, in an hour, whether you've got the shakes from caffeine or general stress.

I don't drink coffee, so I have no idea. But, according to a recent McGill University study, caffeine may impede your body's ability to recover from what would have been short-term hearing loss. Essentially, the pick-me-up energy drink that you down after going to a club may be ensuring your ears never quite bounce back from the damage that night out caused.

"When the ear is exposed to loud noise, it can suffer from a temporary hearing reduction, also called auditory temporary threshold shift," said Dr. Faisal Zawawi, an otolaryngologist—ear, nose, and throat specialist surgeon—and member of the McGill Auditory Sciences Laboratory at the Research Institute of the McGill University Health Centre. "This disorder is usually reversible in the first 72 hours after the exposure, but if symptoms persist, the damage could become permanent."

So, not the best news, if you're to take it at face value. Let's get a couple of things straight, though. This research was based on tests done on guinea pigs, and not people, so we haven't seen the hypothesis control-tested on our species yet. Dr Zawawi and his fellow researchers had first come across what looked like a link between caffeine consumption and hearing loss in their previous work, so decided to devote more time to exploring their earlier findings.

They then exposed two groups of test guinea pigs to loud-ish noise—110db, about equivalent to a typical amplified gig—for an hour. The control group didn't consume any caffeine, while the test group were given a daily dose of 25mg/kg of caffeine. After a day, both groups exhibited a similar level of hearing loss. But after eight days, the research team said that the control group had almost recovered while the caffeinated guinea pig group still suffered hearing impairment. "Our research confirmed that exposure to loud auditory stimuli coupled with daily consumption of 25mg/kg of caffeine had a clear negative impact on hearing recovery," Dr. Zawawi concluded.

Now, coffee's one of those substances that's been subject to medical opinion flip-flops for years, vilified as being garbage that will give you a heart attack in the 1970s then championed for reducing your risk of having a stroke and lowering your risk of getting heart disease in the 2010s.

I don't expect anyone reading this to immediately spit a freshly brewed latte over their phone screen, spluttering about the global coffee industry's conspiracy to leave us all partially deaf and caffeine-addicted by middle age. But given the amount of people who drink caffeine every day, and either work around loud noise—in construction, demolition, waste removal, or those stupidly noisy restaurants and venues—the researchers reckon their work is worth knowing about.

It's most important to note that the McGill study was based on glugging down 25mg/kg of caffeine per day. That's well over the recommended daily amount of 3mg/kg—what you'd find in three flat whites from Pret, or two other normal-sized coffees. "Normal-sized coffees"? Is that what you guys in the States call them?

Anyway, you'd need to be drinking about 16 coffees per day and exposing yourself to sustained hearing damage for this to be a thing. If you're drinking that much caffeine anyway, a slow build of long-term hearing loss is probably the least of your worries.

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