Treatment for 2 mo with n 3 polyunsaturated fatty acids reduces adiposity and some atherogenic factors but does not improve insulin sensitivity in women with type 2 diabetes: a randomized controlled study

Am J Clin Nutr. 2007 Dec;86(6):1670-9. doi: 10.1093/ajcn/86.5.1670.


Background: Information is lacking on the potential effect of n-3 polyunsaturated fatty acids (PUFAs) on the adipose tissue of patients with type 2 diabetes.

Objective: We evaluated whether n-3 PUFAs have additional effects on adiposity, insulin sensitivity, adipose tissue function (production of adipokines and inflammatory and atherogenic factors), and gene expression in type 2 diabetes.

Design: Twenty-seven women with type 2 diabetes without hypertriglyceridemia were randomly allocated in a double-blind parallel design to 2 mo of 3 g/d of either fish oil (1.8 g n-3 PUFAs) or placebo (paraffin oil).

Results: Although body weight and energy intake measured by use of a food diary were unchanged, total fat mass (P < 0.019) and subcutaneous adipocyte diameter (P < 0.0018) were lower in the fish oil group than in the placebo group. Insulin sensitivity was not significantly different between the 2 groups (measured by homeostasis model assessment in all patients and by euglycemic-hyperinsulinemic clamp in a subgroup of 5 patients per group). By contrast, atherogenic risk factors, including plasma triacylglycerol (P < 0.03), the ratio of triacylglycerol to HDL cholesterol (atherogenic index, P < 0.03), and plasma plasminogen activator inhibitor-1 (P < 0.01), were lower in the fish oil group than in the placebo group. In addition, a subset of inflammation-related genes was reduced in subcutaneous adipose tissue after the fish oil, but not the placebo, treatment.

Conclusions: A moderate dose of n-3 PUFAs for 2 mo reduced adiposity and atherogenic markers without deterioration of insulin sensitivity in subjects with type 2 diabetes. Some adipose tissue inflammation-related genes were also reduced. These beneficial effects could be linked to morphologic and inflammatory changes in adipose tissue. This trial was registered at as NCT0037.

Trial registration: NCT00000037 NCT00000037.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipokines / genetics
  • Adipokines / metabolism
  • Blood Glucose / metabolism
  • Body Weight / drug effects
  • Cholesterol / blood
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / diet therapy*
  • Diabetes Mellitus, Type 2 / genetics
  • Double-Blind Method
  • Fatty Acids, Omega-3 / administration & dosage*
  • Female
  • Fish Oils / administration & dosage*
  • Gene Expression Regulation
  • Humans
  • Insulin / blood
  • Insulin Resistance / physiology*
  • Middle Aged
  • Oligonucleotide Array Sequence Analysis
  • Plasminogen Activator Inhibitor 1 / blood
  • Subcutaneous Fat / drug effects*
  • Subcutaneous Fat / physiology
  • Triglycerides / blood


  • Adipokines
  • Blood Glucose
  • Fatty Acids, Omega-3
  • Fish Oils
  • Insulin
  • Plasminogen Activator Inhibitor 1
  • SERPINE1 protein, human
  • Triglycerides
  • Cholesterol

Associated data