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

- We assessed the correlations between the nutrient intake and metabolic parameters.
- Oral intake of fish oil, magnesium, and zinc was associated with some metabolic parameters.
- Fish oil including ω-3 polyunsaturated fatty acid and zinc is associated with increased serum high-density lipoprotein cholesterol levels.
- ω-3 Polyunsaturated fatty acid is associated with reduced liver inflammation in women.
- Zinc is associated with reduced systolic blood pressure in women.

ObjectiveThe 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.MethodsCorrelation 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.ResultsSpearman'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.ConclusionIntake 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.