An oily fish diet increases insulin sensitivity compared to a red meat diet in young iron-deficient women.

Beneficial effects of n-3 fatty acids on a variety of physiological functions have been reported, but information related to the effects of oily fish consumed within a varied diet on glucose metabolism and diabetes risk is scarce. The objective of the study was to compare the effects of a diet rich in oily fish to those of a diet rich in red meat on lipid profile, oxidative status, glucose metabolism and insulin sensitivity in young, iron-deficient women. The study was designed attending the CONSORT statement guidelines. It was a randomised crossover dietary intervention study with two 8-week periods. Two diets were designed differing only in their oily fish or red meat content (four portions per week). Twenty-five young iron-deficient women with normal lipid, glucose and insulin levels participated in the assay. Lipid profile (total, LDL- and HDL-cholesterol, TAG), fasting glucose, fasting insulin, and oxidation (lipoperoxides) and inflammation (soluble intercellular adhesion molecule-1 and soluble vascular cell adhesion molecule-1) biomarkers were analysed. Insulin sensitivity was assessed by the Homeostasis Model Assessment (HOMA) and Quantitative Insulin Sensitivity Check Index (QUICKI). Insulin levels significantly decreased and insulin sensitivity significantly increased with the oily fish diet. HDL-cholesterol significantly increased with the oily fish diet. Other parameters did not significantly differ between diets. An increase in oily fish consumption increases insulin sensitivity in young iron-deficient women. This outcome should be considered when giving dietary advice to this population.