The consumption of seafood, which is major sources of n-3 polyunsaturated fatty acids, such as docosahexaenoic and eicosapentaenoic acids, has been associated with sleep quality. Seafood and its bioactive components may enhance sleep quality by regulating systemic inflammation and neuroendocrine pathways. However, longitudinal studies examining the interplay between seafood consumption, sleep quality, and inflammatory status are lacking. Therefore, in this cohort study of 2,332 participants from the Korean Genome and Epidemiology Study, we investigated the potential modulatory role of inflammatory status for the association between seafood consumption and the risk of poor sleep quality.

Dietary intake was assessed using a validated 106-item food frequency questionnaire. High-sensitivity C-reactive protein (hs-CRP) levels were assessed as a marker of systematic inflammatory status. Sleep quality was assessed using Pittsburgh Sleep Quality Index. The hazard ratio (HR) and 95% confidence interval (CI) for the risk of poor sleep quality was estimated using Cox proportional hazards model.

After 6 years of follow-up, 118 and 192 cases of poor sleep quality were documented among men and women, respectively. The greater seafood consumption was significantly associated with lower risk of poor sleep quality. The multivariable-adjusted HR (95% CI) comparing the highest with the lowest tertile of seafood consumption was 0.66 (0.44–0.97) (p-trend = 0.030). This inverse association appeared to be limited to participants with lower levels of hs-CRP.

Our results suggested that the favorable effects of seafood consumption on sleep quality could vary by inflammatory status. Larger cohort studies are warranted to replicate our findings.