Fish consumption and resilience to depression in Japanese company workers: a cross-sectional study

Abstract

Background: Depression is a common disorder that is influenced by psychosocial factors in the workplace. Increasing resilience, the ability to cope with stress in the face of adversity, is considered an important strategy to prevent depression. It has been suggested that consumption of fish, which is a major source of long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), may prevent depression. However, associations between depression, resilience, and fish consumption have not been documented. The aim of the study is to investigate the association between fish consumption and resilience to depression.

Methods: Participants were 527 Japanese employees at three worksites of a large company. The Center for Epidemiologic Studies Depression (CES-D) Scale was administered to assess depressive symptoms, and the 14-item Resilience Scale (RS-14) was administered to assess resilience. A self-report questionnaire extracted from the Food Frequency Questionnaire was used to measure fish consumption frequency. Regression analyses were conducted to assess a mediation model based on a statistical analysis framework defined by Baron and Kenny. The indirect association of resilience was calculated with the bootstrapping method. Each analysis was adjusted by age, sex, marital status, work position, and educational background.

Results: The association between fish consumption frequency and total CES-D score was significant (B=-0.94; p=0.011). The association between fish consumption frequency and total RS-14 score was significant (B=1.4; p=0.010), as was association total RS-14 score and the total CES-D score (B=-0.34; p<0.001). When controlling for total RS-14 score, there was no longer a significant association between fish consumption frequency and total CES-D score. The bootstrapping results revealed that significant indirect association though fish consumption frequency and total CES-D score (bias corrected and accelerated confidence interval=-0.83 to -0.13; 95% confidence interval) through total RS-14 score.

Conclusions: Fish consumption might be associated with resilience to depression. Further studies are needed, particularly double blind randomized placebo controlled intervention trials on the potential preventative effect of LC n-3 PUFA on resilience to depression.

Fig. 1

a Illustration of a direct association of the dietary factor of fish consumption on depression. Path c represents the total association of fish consumption on depression (CES-D). b Illustration of an indirect association between fish consumption and depression (CES-D) through resilience (RS-14). Path a represents the association between fish consumption and resilience (RS-14), the proposed mediator. Path b represents the association between resilience (RS-14) and depression (CES-D), without fish consumption. Path c′ is the association between the fish consumption and depression (CES-D), without resilience (RS-14). The indirect association between the fish consumption and depression (CES-D) through resilience (RS-14) score is c – c′, which is tested with the confidence interval obtained through the bootstrapping method