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 (English)In: NMCD. Nutrition Metabolism and Cardiovascular Diseases, ISSN 0939-4753, E-ISSN 1590-3729, Vol. 17, no 8, 572-580 p.Article in journal (Refereed) Published
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).
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.
Place, publisher, year, edition, pages
2007. Vol. 17, no 8, 572-580 p.
Diet, Fish oil, Insulin sensitivity, Insulin secretion, Glucose tolerance
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-23280DOI: 10.1016/j.numecd.2006.06.006ISI: 000250192400003PubMedID: 17127043OAI: oai:DiVA.org:uu-23280DiVA: diva2:51054