Background: Excessive energy intake and obesity lead to the metabolic syndrome (MetS). Dietary saturated fatty acids (SFAs) may be particularly detrimental on insulin sensitivity (SI) and on other components of the metabolic syndrome.
Objective: This study determined the relative efficacy of reducing dietary saturated fatty acids, by isoenergetic alteration of the quality and quantity of dietary fat, on risk factors associated with metabolic syndrome.
Design: A free-living, single-blinded dietary intervention study.
Subjects and Methods: metabolic syndrome subjects (n=417) from eight European countries completed the randomized dietary intervention study with four isoenergetic diets distinct in fat quantity and quality:
• High-saturated fatty acids [e.g., reducing cheese, butter, fatty meat, chocolate];
• High-monounsaturated fatty acids [e.g., reducing nuts, vegetable/olive oils, eggs]
• And two low-fat, high-complex carbohydrate (LFHCC) diets, [e.g. high in fiber-rich whole grains, peas & beans] supplemented with
- Long chain Omega-3 polyunsaturated fatty acids (LC Omega-3 PUFAs) (1.2g per day) [e.g. fish oil]
- Or placebo for 12 weeks.
Insulin sensitivity estimated from an intravenous glucose tolerance test (IVGTT) was the primary outcome measure.
Lipid and inflammatory markers associated with metabolic syndrome were also determined.
Results: In weight-stable subjects:
• Reducing dietary saturated fatty acids intake had no effect on insulin sensitivity, total and low-density lipoprotein cholesterol concentration, inflammation or blood pressure in the entire cohort.
• The low-fat, high-complex carbohydrate Omega-3 PUFA diet reduced plasma triacylglycerol (TAG) and non-esterified fatty acid concentrations (P<0.01), particularly in men.
Conclusion: There was no effect of reducing saturated fatty acids on insulin sensitivity in weight-stable obese metabolic syndrome subjects.
Long chain Omega-3 PUFA supplementation, in association with a low-fat diet, improved TAG-related metabolic syndrome risk profiles.
Source: International Journal of Obesity, Oct 12, PMID: 20938439, by Tierney AC, McMonagle J, Shaw DI, Gulseth HL, Helal O, Saris WH, Paniagua JA, Go??bek-Leszczyñska I, Defoort C, Williams CM, Karsltröm B, Vessby B, Dembinska-Kiec A, López-Miranda J, Blaak EE, Drevon CA, Gibney MJ, Lovegrove JA, Roche HM. Nutrigenomics Research Group, UCD Conway Institute & UCD Institute of Food & Health, University College Dublin, Ireland.