Healthy diet linked to lower risk of hearing loss: Study

Eating a healthy diet is associated with a reduced risk of acquired hearing loss, according to a study.

The study, published in the American Journal of Epidemiology, examined three-year changes in hearing sensitivities in women with a mean age of 69 years.

The researchers found that women whose eating patterns more closely adhered to commonly recommended healthful dietary patterns, had substantially lower risk of decline in hearing sensitivity.

"A common perception is that hearing loss is an inevitable part of the ageing process. However, our research focuses on identifying potentially modifiable risk factors -- that is, things that we can change in our diet and lifestyle to prevent hearing loss or delay its progression," said lead author Sharon Curhan, from Brigham and Women's Hospital in the US.

"The benefits of adherence to healthful dietary patterns have been associated with numerous positive health outcomes, and eating a healthy diet may also help reduce the risk of hearing loss," Curhan said in a statement.

Previous studies have suggested that higher intake of specific nutrients and certain foods, such as the carotenoids beta-carotene and beta-cryptoxanthin, folate, and long-chain omega-3 fatty acids, were associated with lower risk of self-reported hearing loss.

These findings revealed that dietary intake could influence the risk of developing hearing loss.

However, the researchers sought to further understand the connection between diet and hearing loss by capturing overall dietary patterns and objectively measuring longitudinal changes in hearing sensitivities.

They established 19 geographically diverse testing sites across the US, and trained licensed audiologists to measure changes in pure-tone hearing thresholds, the lowest volume that a pitch can be detected by the participant in a given ear, over the course of three years.

Using over 20 years of dietary intake information that was collected every four years beginning in 1991, the researchers investigated how closely participants' long-term diets resembled some well-established and currently recommended dietary patterns, such as the DASH diet, the Mediterranean diet, and Alternate Healthy Index-2010 (AHEI-2010).

Greater adherence to these dietary patterns has been associated with a number of important health outcomes, including lower risk of heart disease, hypertension, diabetes, stroke and death as well as healthy aging, the researchers said.

The team found that the odds of a decline in mid-frequency hearing sensitivities were almost 30 per cent lower among those whose diets most closely resembled these healthful dietary patterns, compared with women whose diets least resembled the healthful dietary patterns.

In the higher frequencies, the odds were up to 25 per cent lower, according to the study.

"The association between diet and hearing sensitivity decline encompassed frequencies that are critical for speech understanding," said Curhan.

"We were surprised that so many women demonstrated hearing decline over such a relatively short period of time," she said.

The mean age of the women in the study was 59 years, and most of the participants were in their 50s and early 60s.

This is a younger age than when many people think about having their hearing checked, the researchers noted.