Association between frequency of fried food consumption and resilience to depression in Japanese company workers: a cross-sectional study

Eisho Yoshikawa, Daisuke Nishi, Yutaka J. Matsuoka

Long-chain n-3 and n-6 polyunsaturated fatty acids (LC n-3/n-6 PUFA) play important roles in emotional regulation. We previously reported an association between fish consumption, which is major source of LC n-3 PUFA, and resilience to depression, where resilience is the ability to cope with stress in the face of adversity. Although the traditional Japanese dietary pattern of high fish consumption is associated with low depressive symptoms, the current Japanese diet pattern has become westernized. Westernized diets contain excessive amounts of LC n-6 PUFA due to high intake of vegetable oils commonly used in fried food and are associated with risk of depression. The aim of this study was to examine the association between frequency of fried food consumption and resilience to depression. Participants were 715 Japanese company workers. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to measure depressive symptoms, and the 14-item Resilience Scale (RS-14) was used to measure resilience. Frequency of fish and fried food consumption was assessed using a self-report questionnaire based on the Food Frequency Questionnaire. Regression analyses using Preacher and Hayes' bootstrap script were used to adjust for demographic factors, frequency of physical exercise, and fish consumption. Significant associations were identified between frequency of fried food consumption and total CES-D score (path c, B = 0.72; P < 0.01), between frequency of fried food consumption and total RS-14 score (path a, B = -1.73, P < 0.01), and between total RS-14 score and CES-D score (path b, B = -0.35; P < 0.01). The association between fried food consumption and total CES-D score was not significant when we controlled for RS-14 score. Bootstrapping results showed that there was a significant positive indirect association between frequency of fried food and CESD score through RS-14 (95 % bias-corrected and accelerated confidence interval = 0.34 to 0.92). Frequency of fried food consumption was associated with lower resilience to depression. Further nutritional interventional studies to increase resilience and prevent depression are warranted.