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- Giacco, R., et al.
(författare)
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Fish oil, insulin sensitivity, insulin secretion and glucose tolerance in healthy people : Is there any effect of fish oil supplementation in relation to the type of background diet and habitual dietary intake of n-6 and n-3 fatty acids?
- 2007
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Ingår i: NMCD. Nutrition Metabolism and Cardiovascular Diseases. - : Elsevier BV. - 0939-4753 .- 1590-3729. ; 17:8, s. 572-580
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Tidskriftsartikel (refereegranskat)abstract
- Aim To evaluate whether a moderate supplementation of long-chain n-3 fatty acids is able to modulate insulin sensitivity, insulin secretion, β-cell function and glucose tolerance in healthy individuals consuming a diet rich in either saturated or monounsaturated fat, also in relation to their habitual dietary intake of n-6 and n-3 fatty acid. Methods and results One hundred and sixty-two healthy individuals were randomly assigned to follow either one of two isoenergetic diets for 3months, one rich in monounsaturated fats and the other rich in saturated fats. Within each group there was a second randomisation to fish oil (n-3 fatty acids 3.6g/day) or placebo. At the beginning and at the end of the treatment periods insulin sensitivity (SI), first phase insulin response (FPIR) and glucose tolerance (KG-value) were evaluated by the intravenous glucose tolerance test (IVGTT). Fish oil did not have any effect on SI, FPIR, KG-value and disposition index in either diet. Even after dividing subjects according to the median value of n-6/n-3 ratio of serum phospholipids at baseline, there was no change in SI (Δ SI 0.42±0.34 on fish oil vs 0.14±0.23 on placebo for those with n-6/n-3 <4.85; −1.03±0.47 on fish oil vs −0.27±0.32 on placebo for those with n-6/n-3 >4.85) (M±SE), FPIR (Δ FPIR 135.9±78.9 vs 157.2±157.5pmol/L; 38.8±181.7 vs 357.1±181.7pmol/L), KG-value (Δ KG 0.14±0.15 vs 0.12±0.11; −0.32±0.16 vs 0.15±0.15) or disposition index (Δ disposition index 1465.4±830.4 vs 953.8±690.0; −1641.6±1034.3 vs 446.6±905.1). Considering the 75th percentile of n-6/n-3 ratio (5.82) the results on insulin sensitivity, insulin secretion and disposition index were confirmed, while, in this more extreme situation, n-3 fatty acid supplementation induced a significant deterioration of KG-value (p=0.02). Conclusions In healthy individuals a moderate supplementation of fish oil does not affect insulin sensitivity, insulin secretion, β-cell function or glucose tolerance. The same is true even when the habitual dietary intake of n-6 and n-3 fatty acids is taken into account.
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| 3. |
- Nälsén, C, et al.
(författare)
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Dietary (n-3) fatty acids reduce plasma F2-isoprostanes but not prostaglandin F2alpha in healthy humans
- 2006
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Ingår i: Journal of Nutrition. - 0022-3166 .- 1541-6100. ; 136:5, s. 1222-1228
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Tidskriftsartikel (refereegranskat)abstract
- (n-3) Fatty acids are unsaturated and are therefore easily subject to oxidization; however, they have several beneficial health effects, which include protection against cardiovascular diseases. The aim of this study was to investigate whether (n-3) fatty acids, with a controlled fat quality in the background diet, affect nonenzymatic and enzymatic lipid peroxidation and antioxidant status in humans. A total of 162 men and women in a multicenter study (The KANWU study) were randomly assigned to a diet containing a high proportion of saturated fatty acids or monounsaturated fatty acids (MUFA) for 3 mo. Within each diet group, there was a second random assignment to supplementation with fish-oil capsules [3.6 g (n-3) fatty acids/d] or placebo. Biomarkers of nonenzymatic and enzymatic lipid peroxidation in vivo were determined by measuring 8-iso-prostaglandin F2α (8-iso-PGF2α) and prostaglandin F2α (PGF2α) concentrations in plasma at baseline and after 3 mo. Antioxidant status was determined by measuring plasma antioxidant capacity with an enhanced chemiluminescence assay. The plasma 8-iso-PGF2α concentration was significantly decreased after 3 mo of supplementation with (n-3) fatty acids (P = 0.015), whereas the PGF2α concentration was not affected. The antioxidant status was not affected by supplementation of (n-3) fatty acids, but was improved by the background diet with a high proportion of MUFA. We conclude that supplementation with (n-3) fatty acids decreases nonenzymatic free radical–catalyzed isoprostane formation, but does not affect cyclooxygenase-mediated prostaglandin formation.
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