Higher dietary intake of omega-3 and omega-6 polyunsaturated fatty acids was associated with lower odds of high-frequency hearing loss among US adults aged 30 to 69 years, according to a cross-sectional analysis of National Health and Nutrition Examination Survey data.
The study included 6,454 participants (mean age, 49 years; 51% women) from the 2011 to 2012 and 2015 to 2016 NHANES cycles. Overall, about 45% of participants had high-frequency hearing loss, defined as an average pure tone threshold greater than 25 dB at frequencies of 3000 to 8000 Hz in both ears.
After adjustment for demographic, clinical, and lifestyle factors, higher intake of omega-3 and omega-6 polyunsaturated fatty acids was associated with lower odds of high-frequency hearing loss. Each 1-unit increase in omega-3 intake was associated with about 7% lower odds, while each 10-unit increase in omega-6 intake was associated with about 10% lower odds.
For omega-3 intake, lower odds of high-frequency hearing loss were observed beginning in the third quintile and above, whereas the second quintile showed no meaningful association. Participants in these higher intake groups had roughly 20% to 30% lower odds compared with those consuming 0.86 g/day or less.
For omega-6 intake, lower odds of high-frequency hearing loss were observed beginning in the fourth quintile, while the highest quintile showed a similar magnitude of association that did not reach statistical significance. Participants in these higher intake groups had about 20% to 25% lower odds compared with those in the lowest intake group.
Restricted cubic spline analyses demonstrated a linear inverse dose-response relationship between both fatty acid types and hearing loss, with no evidence of a nonlinear pattern. In contrast, the ratio of omega-6 to omega-3 intake was not associated with hearing loss in either continuous or categorical analyses.
Subgroup analyses showed consistent findings for omega-3 intake across patient groups. For omega-6 intake, an interaction was observed by race and ethnicity, while other subgroup analyses did not show meaningful differences. Sensitivity analyses yielded similar results, supporting the robustness of the findings.
Dietary intake was assessed using two 24-hour recall interviews, and hearing thresholds were measured with standardized audiometry in soundproof environments. The analyses adjusted for a broad range of covariates, including comorbidities, noise exposure, medication use, and additional dietary factors.
The researchers noted several limitations, including the cross-sectional design, which precludes causal inference, the possibility of residual confounding, and potential recall bias in dietary reporting.
“Higher dietary intake of polyunsaturated fatty acids was associated with a lower likelihood of high-frequency hearing loss in adults in the United States,” wrote Zhaocha Gao, BS, of the Department of Otolaryngology–Head and Neck Surgery, Affiliated Hospital of Jining Medical University in China, and colleagues.
The researchers reported no conflicts of interest.
Source: Medicine