The acute phase reactions, associated with injury, inflammation, or sepsis, markedly affect the concentration and composition of plasma lipids and lipoproteins. Hepatic production of triglycerides and very low density lipoprotein formation are increased, but do not necessarily result in high plasma triglyceride levels. In contrast, all conditions lower plasma cholesterol by decreasing its content in both low-density and high-density lipoproteins. In addition, substantial changes in protein and lipid composition of lipoproteins are observed that may redefine the function of these particles, but also increase their atherogenic and inflammatory properties.

Relative absorption of conjugated linoleic acid as triacylglycerol, free fatty acid and ethyl ester in a functional food matrixConjugated linoleic acid (CLA) shows potential benefits in a number of medical conditions, making it a possible target for incorporation into a functional food. Until recently, clinical trials were conducted with various mixtures of CLA isomers, encapsulated as the free acid. The purpose of this study was to examine a mixture of two specific CLA isomers (9c,11t and 10t,12c), incorporated into a functional food either as triacylglycerol, free fatty acid or fatty acid ethyl ester. Differences in absorption between the lipid forms and between the isomers were investigated. The palatability of the different functional-food formulations was also studied. Significantly less CLA was absorbed into chylomicrons over six hours when fed as fatty acid ethyl ester than when either the triacylglycerol or free fatty acid forms were fed. Further work is recommended, to examine fatty acid ethyl ester absorption over longer periods of time. Most subjects reported that the fatty acid formulation had poor taste characteristics. We conclude that CLA as triacylglycerol is the most suitable form for incorporation into a functional food and that the 9c,11t and 10t,12c CLA isomers are absorbed similarly into chylomicrons.Keywords: Absorption, CLA, functional food, triacylglycerol, ethyl ester. IntroductionConjugated linoleic acid (CLA) is the collective name given to C18 fatty acid positional and geometric isomers, containing two conjugated double bonds. CLA is a minor component of dairy and ruminant fats and is also a product of autoxidation and partial hydrogenation of polyunsaturated fats. There is increasing interest in CLA, as in animal trials it has shown potentially beneficial effects on a number of medical conditions, including cancer and diabetes, as well as altered body composition. The results from human studies are less conclusive [1] but its potential as the active component of a functional food is being explored [2,3].A major difference between a functional food and a pharmaceutical is that, although both must provide the active ingredient in a form that ensures a reasonable level of uptake, the functional food has also to be appealing to the consumer for long-term consumption as part of the daily diet. Most of the previous human studies have used CLA as the free acid, usually in capsules, containing a variety of isomeric mixtures, since this was the only material that was readily available. However, the increased interest in CLA has led to the production of CLA with excellent isomeric purity [4], both as free acid and more recently as triacylglycerol.The FunCLA project (funded by EU grant QLK1-CT99-00076) was set up to apply a functional food approach to examining two specific CLA isomers, with regard to their individual effects on body composition, diabetes, metabolic parameters and hyperlipidaemia in humans. The object of the first part of the project was to examine the absorption of a mixture co...