Influence of dietary intake of fish oil, magnesium, and zinc on metabolic parameters among individuals tested for diabetes

Abstract Objective The aim of this study was to assess the significance and degree of correlation between the intake of fish oil, magnesium (Mg), and zinc (Zn) and metabolic parameters. Methods Correlation coefficients among nutrient intake and physical and laboratory parameters were determined using Spearman's rho (ρ) test or a multiple regression model among Japanese individuals (male:female, 37:66; median age, 55 y) who completed a semiquantitative food questionnaire and underwent testing for diabetes. Individuals with diabetes were excluded. Results Spearman's test revealed several weak but significant correlations between intake of fish oil including ω-3 polyunsaturated fatty acids (PUFAs) and various metabolic parameters. The test showed that Zn intake in women significantly correlated with reduced systolic blood pressure (SBP), alanine aminotransferase (ALT), γ-glutamyl transpeptidase (γ-GPT), and homeostasis model assessment–insulin resistance (HOMA-IR). Multivariate analysis revealed that intake of fish oil, eicosapentaenoic acid (EPA), and Zn was significantly associated with increased serum levels of high-density lipoprotein cholesterol (HDL-C; fish oil versus HDL-C, P = 0.0438; 95% confidence interval [CI], 0.0055–0.3724; EPA versus HDL-C, P = 0.0439; 95% CI, 0.0053–0.3724; Zn versus HDL-C, P = 0.0041; 95% CI, 0.0890–0.4609). Multivariate analysis revealed that ω-3 PUFAs were associated with decreased serum ALT levels ( P = 0.0240; 95% CI, −5.000 to −0.0367) and that Zn correlated with SBP ( P = 0.0239; 95% CI, −0.5149 to −0.0377) in women. Conclusion Intake of fish oil, Mg, and Zn was associated with some metabolic parameters. Abundant intake of fish oil including ω-3 PUFAs and Zn can exert antiarteriosclerotic effects through increasing serum levels of HDL-C. ω-3 PUFAs can reduce liver inflammation and Zn can reduce SBP in women.