11 October 2011

People with black skin better protected against hearing loss

The explanation as to why black skinned people hear better than people with white skin may lie in the cell pigment in their skin, which produces the skin-protecting melanin.

Researchers from Johns Hopkins University in the US have found that dark-skinned people are much less likely than people with white skin to suffer from hearing loss. The results indicate that there is a link to the melanocytes in our skin.

Originally, the study was about the general distribution of hearing loss and its risk in the elderly. Here, the researchers found that two-thirds of those older than 70 had a hearing loss. What was more interesting, however, was that 64% of the whites in the survey had a hearing loss compared to only 43% of those with black skin. Similar results have proved that darker-skinned whites are more likely to have better hearing than whites with pale skin.

Pigments protect against hearing loss

The research suggested that the explanation lies in the so-called melanocytes, the cell pigments in the skin which produces the skin-protecting melanin. The head of the study, Frank Lin, noted that further research is needed to completely confirm these results. In a second step, the researchers want to discover the relationship between hearing and ethnic origin on the basis of the temporal bone. In further research, Lin wants to concentrate on the cell structure and examine if there is a difference in the cochlea depending on skin colour

Earlier studies also confirm the new results. In one study, the noise-related hearing loss was examined in black and white metal factory workers. It was found that blacks were exposed to a lower risk of hearing loss than their white colleagues.

The study was based on the demographic data from the National Health and Nutrition Examination Survey (NHANES) in the US. This program, headed by the National Center for Health Statistics (NCHS), has collected data for the past 40 years. The recent study involved an analysis of data based on 717 people.

Source: Hörakustik 7/2011