Effects of simultaneous intakes of fish oil and green tea extracts on plasma, glucose, insulin, C-peptide, and adiponectin and on liver lipid concentrations in mice fed low- and high-fat diets.

AIMS: The purpose of this study was to clarify the effects of a simultaneous intake of fish oil and green tea extracts (GTE) on plasma lipids, glucose (Glu), insulin, C-peptide, and adiponectin concentrations and on liver lipids in mice fed low- and high-fat diets.

METHODS: Male mice (5 months old) were fed low-fat (5%) or high-fat (20%) diets containing 0% (5 or 20% lard), 1% (4 or 19% lard) or 5% (0 or 15% lard) fish oil with or without 1% GTE for 3 months.

RESULTS: Single or combined intakes of fish oil and GTE intakes significantly lowered plasma and liver total cholesterol (T-chol) and triacylglycerol (TG) concentrations in mice on high-fat diets. However, a positive effect of GTE alone was not observed in the plasma T-chol and TG concentrations of mice on low-fat diets. Plasma Glu concentrations were significantly lowered by dietary fish oil in mice on the low- and high-fat diets. A tendency of GTE intake to decrease plasma Glu in mice on both the low- and high-fat diets was not significant. An intake of GTE only minimally influenced plasma insulin, C-peptide, and adiponectin concentrations, but fish oil supplementation increased the adiponectin concentration in mice on the low- and high-fat diets. GTE addition to the diets had no adverse effects on reductions by fish oil.

CONCLUSION: These results suggest that a simultaneous intake of fish oil and GTE can improve plasma and liver lipid and plasma Glu profiles in mice fed a high-fat diet without any negative interactions of fish oil and GTE.