Longitudinal study of seafood and fish oil supplement intake and risk of persistent tinnitus.

Background: Persistent tinnitus is common, disabling, and difficult to treat. Diet has been implicated in tinnitus etiology, but studies are inconsistent, and longitudinal data are scarce. Seafood intake is associated with a lower risk of hearing loss, but the longitudinal association with tinnitus is unknown.

Objectives: We examined the independent associations of seafood intake, fish oil supplement use, and risk of developing persistent tinnitus.

Methods: This prospective cohort study followed 73,482 females in the Nurses' Health Study II from 1991 to 2021. Diet was assessed using a validated food frequency questionnaire every 4 y. Multivariable-adjusted Cox proportional hazards regression was used to evaluate independent associations between total seafood intake, specific types of fish, shellfish, fish oil supplements, and risk of persistent tinnitus (defined as tinnitus experienced daily).

Results: After 1,998,421 person-y of follow-up, 9362 cases of incident persistent tinnitus were reported. Seafood intake was independently associated with a lower risk of developing persistent tinnitus. Compared with participants who never or rarely consumed seafood, the multivariable-adjusted hazard ratios (MVHRs; 95% confidence interval) for tinnitus were 0.87 (0.78, 0.95) among participants who consumed 1 serving/wk, 0.77 (0.68, 0.86) for 2-4 servings/wk, and 0.79 (0.64, 0.96) for 5+/servings/wk (P-trend < 0.0001). Examined individually, higher intakes of tuna fish, light-meat fish and shellfish were associated with lower risk. Compared with participants who never or rarely consumed the specific type, the MVHRs for consumption of 1+ servings/wk were 0.84 (0.78, 0.90) (P-trend < 0.0001) for tuna fish, 0.91 (0.83, 0.99) (P-trend = 0.04) for light-meat fish, and 0.82 (0.72, 0.93) (P-trend < 0.0001) for shellfish. A higher risk for dark-meat fish intake was suggested [MVHR: 1.09 (0.99, 1.21) (P-trend = 0.04)]. Fish oil supplement use (yes/no) was associated with higher risk [MVHR: 1.12 (1.06, 1.19)].

Conclusions: Regular consumption of tuna fish, light-meat fish, or shellfish is associated with a lower risk of developing persistent tinnitus in females. Fish oil supplement use is associated with higher risk.