That bottomless cup of morning joe you enjoy the morning after a late night concert might be preventing your ears from recovering. More than three-quarters of American adults enjoy a jolt of caffeine, typically in a cup or two of morning coffee, but recent research, conducted by Dr Faisal Zawawi, Otolaryngologist at the Research Institute of the McGill University Health Centre (RI-MUHC) has found that daily consumption of caffeine might impair recovery after temporary hearing damage.
In a study published in the April, 2016 Journal of the American Medical Association Otolaryngology-Head & Neck Surgery , Dr Zawawi and his colleagues discovered that consistently high doses of caffeine – the types of doses found in energy drinks often consumed by teenagers and young adults—could have a significant impact on hearing sensitivity.
And, since caffeine intake from energy drinks and exposure to loud music seems to be a relatively common pairing, especially among in young adults, the researchers at the McGill Auditory Sciences Laboratory,who have investigated the effects of many substances on temporary threshold shift, looked more closely on the relationship caffeine might have on hearing loss.
Animal Model Shows Negative Impact of Caffiene
According to a McGill University press release, Dr Zawawi and his colleagues used an animal model, exposing two groups to a sound of 110 dB SPL for a period of one hour. Twenty-four female albino guinea pigs, divided randomly into 3 groups of 8 animals each were used in the study. Group 1 was exposed to caffeine; group 2, a 110 dB SPL stimulus; and group 3 was exposed to both caffeine and the 100 dB SPL acoustic stimulus. After eight days, the group without caffeine had recovered almost completely, while hearing impairment persisted in the group receiving daily caffeine.
“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,” said Dr. Zawawi in the McGill University report.
ABR thresholds were recorded after 8 and 15 days of exposure. ABR thresholds were recorded on day 15 and compared with ABR thresholds obtained on day 8. The maximum threshold shift was at 16 kHz, with a mean of 66 dB for the two groups exposed to noise. By day 8, the threshold shift in group 2 recovered completely at all frequencies except 20 kHz.Hearing impairment in group 3 (the group exposed to both noise and caffeine) persisted at the 8-, 16-, and 25-kHz frequencies with thresholds of 21, 28, and 26 dB SPL, respectively (P = .001).
*image courtesy beagenius