Beneficial effects of the n-3 long-chain polyunsaturated fatty acids in surgical patients: updating the evidence

Nutrigenomics of ω-3 fatty acids: Regulators of the master transcription factors

It is well known that ω-3 long-chain polyunsaturated fatty acids (LC-PUFAs) control some key molecular cell mechanisms, resulting in a beneficial role in inflammatory diseases. Such mechanisms are complex and reflect the diversity of their functions, mainly as modulators of the dynamic properties of membranes, regulators of gene expression, and precursors of active mediators. The aim of this review is to summarize the state of the art of the effects and mechanisms by which ω-3 LC-PUFAs such as eicosapentaenoic acid (EPA, C22:5 ω-3) and docosahexaenoic acid (DHA, C22:6 ω-3) regulate different metabolic processes to maintain homeostasis. Thus, we describe some aspects of these fatty acids-from their structural function in cell membranes to their role as regulators of gene expression, mainly in lipid metabolism. However, further studies are required to elucidate these actions and to have a better understanding in regard to the beneficial effects of ω-3 LC-PUFAs in the pathogenesis of several diseases as well as their functions as nutrients with protective action to avoid or delay development of these diseases. Furthermore, it is necessary to highlight the lack of comprehensive studies including nutritional, biochemical, genetic, and immune aspects to identify specific molecular mechanisms involved in the beneficial effects of consumption of DHA (C22:6 ω-3) and EPA (C22:5 ω-3) and their metabolic derivatives on health promotion.

Inflammatory response following heart surgery and association with n-3 and n-6 long-chain polyunsaturated fatty acids in plasma and red blood cell membrane lipids

BACKGROUND

Open heart surgery is associated with a systemic inflammatory response. The n-3 long-chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and the n-6 LC-PUFA arachidonic acid (AA) may contribute to modulation of the inflammatory response.

OBJECTIVE

We investigated whether the preoperative levels of EPA, DHA and AA in plasma phospholipids (PL) and red blood cell (RBC) membrane lipids in patients (n=168) undergoing open heart surgery were associated with changes in the plasma concentration of selected inflammatory mediators in the immediate postoperative period.

RESULTS AND CONCLUSIONS

The postoperative concentration of TNF-β was lower (P<0.05) and those of hs-CRP, IL-6, IL-8, IL-18 and IL-10 higher (P<0.05) than the respective preoperative concentrations. We observed that the preoperative levels of EPA and AA in plasma PL and RBC membrane lipids were associated with changes in the concentration of pro-inflammatory and anti-inflammatory mediators, suggesting a complex role in the postoperative inflammatory process.

Lipid emulsions in parenteral nutrition: current applications and future developments

INTRODUCTION

A parenteral lipid emulsion (LE), used as a key source of energy, essential fatty acids (FAs), and fat-soluble vitamins, is an integral part of a parenteral nutrition (PN) regimen. The conventional LEs, such as soybean oil (SO)-based emulsions, have caused concerns about the potential adverse effects involving oxidative stress, inflammation, and immune response probably because of undesirable FA composition.

AREAS COVERED

Recently, alternative LEs, optimizing the FA composition with partial substitution of SO with medium-chain triglyceride (MCT), olive oil (OO), and fish oil (FO), have been developed and applied in clinical practice. This review summarizes the characteristics and beneficial clinical effects of alternative parenteral LEs in critically ill, pediatric, and long-term PN patients.

EXPERT OPINION

More clinical data from sufficiently high-powered studies are required to characterize the integral biological properties of alternative LEs for further selection to fit individual needs and disease characteristics. Simultaneously, potential lipid sources with desirable FA compositions and biological properties should be selected to develop new therapeutic LEs. As supplements to current parenteral lipids, the new LEs with different therapeutic effects are expected to fit specified subpopulations of patients with different diseases. Great efforts should be devoted to the development of parenteral LEs.