Plasma very long-chain n-3 polyunsaturated fatty acids and age-related hearing loss in older adults.

OBJECTIVES

Age-related hearing loss is a common social and health problem in the older adult population. Up until now, very little scientific attention has been given to the potential role of fatty acids in age-related hearing loss. In this study we investigated whether plasma very long-chain n-3 polyunsaturated fatty acids (PUFAs) are associated with age-related hearing loss over three years.

DESIGN

Cross-sectional and 3-year longitudinal analyses.

SETTING

Wageningen, the Netherlands.

PARTICIPANTS

720 men and postmenopausal women (50-70 years of age) without middle ear dysfunction or unilateral hearing loss.

MEASUREMENTS: Fatty acid proportions were measured in plasma cholesteryl esters. Hearing thresholds (in decibels, dB) at baseline and after three years were measured with pure-tone audiometry. Hearing loss was calculated as the increase in mean hearing thresholds in the low (0.5-kHz, 1-kHz, and 2-kHz) and high (4-kHz, 6-kHz, and 8-kHz) frequencies over three years.

RESULTS

Subjects in the highest quartile of plasma very long-chain n-3 PUFA had less hearing loss in the low frequencies over three years than subjects in the lowest quartile (p < 0.01, ANCOVA, difference in mean adjusted hearing thresholds= -1.2 dB). There were no significant differences between the quartiles of plasma very long-chain n-3 PUFA in hearing loss in the high frequencies (p=0.49, ANCOVA). These associations are adjusted for baseline mean hearing thresholds, age, sex, level of education and alcohol consumption.

CONCLUSION

This study is the first to show an inverse association between plasma very long-chain n-3 PUFAs and age-related hearing loss. These results are encouraging, but require confirmation from future studies.