Researchers at the University of Sydney have examined levels of folate, vitamin B12, and homocysteine in blood and correlated this with the risk of age-related hearing loss. The data showed that folate levels below 11 nanomoles per litre were associated with a 34% increased risk of age-related hearing loss. In addition, levels of homocysteine over 20 micromoles per litre were associated with a 64% increase in the risk of hearing loss. The study was based on a population of 2,956 people aged 50 and over.
In 2009, at the American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNSF) Annual Meeting in San Diego, Boston-based researchers revealed that men over the age of 60 with high folate intake from foods and supplements had a 20% decrease in the risk of developing hearing loss.
In 2007, in a study of 728 men and women between the ages of 50 and 70, scientists from Wageningen University reported that folic acid supplements delayed age-related hearing loss in the low frequency region.
Increased intakes of omega-3 fatty acids, and the fish which provide them, may reduce the risk of age-related hearing loss, according to a study from the University of Sydney. Australian researchers have observed, that at least two servings of fish per week is associated with a 42% reduction in the risk of hearing loss in those over 50, compared with people who on average eat fish less than once per week.
High levels of vitamin A are associated with a lower prevalence of hearing loss, according to Japanese researchers. The researchers compared the presence of vitamin A in the subject's serum to the subject's hearing.
Finally, researchers at the University of California in San Diego have discovered, that the protein Sox2 is involved in the process through which stem cells develop into ganglion neurons - the nerve cells that send sound representations to the brain.
- Folate may reduce or delay hearing loss
- Omega-3 may protect against hearing loss
- Vitamin A may protect from hearing loss
- Protein can help to restore hearing