New oral fat tolerance tests feature tailoring of the polyunsaturated/saturated fatty acid ratio to elicit a specific postprandial response

Appl Physiol Nutr Metab. 2007 Dec;32(6):1073-81. doi: 10.1139/H07-101.

Abstract

The impact of dietary fat on postprandial metabolic biomarkers for obesity-related chronic diseases, such as type-2 diabetes and cardiovascular disease, has received significant recent attention. However, there is no standard method to evaluate the postprandial response to dietary fat alone. Our goals were to develop a novel oral fat tolerance test (OFTT) consisting solely of emulsified lipids tailored for specific fatty acid compositions and to evaluate the functionality of specific ratios of polyunsaturated/saturated fatty acid (P/S) loading on postprandial triacylglyceride (TAG) concentrations. Two OFTTs of emulsified lipids were prepared with specific P/S ratios of 0.2 and 2.0. Physical characteristics of the fat blends, including TAG composition, melting point, and emulsion droplet size were quantified. Healthy, older (age>45 y) men (n=8) underwent an 8 h postprandial study wherein they received the OFTT treatment (either the P/S ratio of 0.2 or 2.0), with a total lipid load of 1 g/kg subject body mass. All subjects received both treatments separated by at least 1 week. Both the P/S 0.2 and 2.0 OFTT significantly elevated (p<0.05) blood TAG and free fatty acid concentrations for 8 h without increasing blood glucose or serum insulin concentrations. The predominant fatty acids contained in the P/S 0.2 (palmitic acid, 16:0) and 2.0 (linoleic acid, 18:2(n-6)) OFTT blends were significantly elevated in the blood (p<0.05) during their respective postprandial periods. We concluded that blood TAGs are elevated in a specific pattern through the administration of novel OFTTs with specific P/S blends without eliciting an insulin or glucose response.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Beverages
  • Blood Glucose / metabolism
  • Dietary Fats / pharmacology*
  • Double-Blind Method
  • Emulsions
  • Fatty Acids / blood
  • Fatty Acids / chemistry
  • Fatty Acids / pharmacology*
  • Fatty Acids, Nonesterified / blood
  • Fatty Acids, Unsaturated / chemistry
  • Fatty Acids, Unsaturated / pharmacology*
  • Humans
  • Insulin / blood
  • Lipids / blood
  • Male
  • Middle Aged
  • Postprandial Period / drug effects*
  • Triglycerides / pharmacology

Substances

  • Blood Glucose
  • Dietary Fats
  • Emulsions
  • Fatty Acids
  • Fatty Acids, Nonesterified
  • Fatty Acids, Unsaturated
  • Insulin
  • Lipids
  • Triglycerides