Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - PIMS (Mechanistic studies of long chain omega-3 fatty acid supplementation and inflammation in metabolic syndrome.)

Teaser

Chronic inflammation, which describes a state of low but sustained blood levels of proteins that play a role in the response to injury and acute disease, is now indisputably recognized as a key risk factor for heart disease. Obesity is a frequent cause of chronic inflammation...

Summary

Chronic inflammation, which describes a state of low but sustained blood levels of proteins that play a role in the response to injury and acute disease, is now indisputably recognized as a key risk factor for heart disease. Obesity is a frequent cause of chronic inflammation, leading to a state of metabolic disorders such as increased blood lipids and hypertension, a state frequently referred to as metabolic syndrome (MetS). With the increasing obesity rates worldwide, we can expect parallel increases in the prevalence of MetS and associated heart disease risk over the next decades, with unprecedented social and economic impacts on the global health care burden. It therefore becomes of highest priority to investigate strategies to prevent or decrease chronic inflammation in at-risk patients. Nutritional strategies play a major role, especially those based on omega 3 fatty acid dietary supplements. Indeed, omega 3 fatty acids, notably eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), have raised tremendous interest notably for their blood lipid lowering effect and purported anti-inflammatory potential. However, data from rigorously conducted clinical studies supporting anti-inflammatory effects of omega 3 fatty acids are surprisingly lacking. Moreover, almost all studies so far have used a mix of omega 3 fatty acids, notably DHA and EPA together. Therefore, it remains unclear if DHA and EPA have similar or different effects on chronic inflammation, and if so, by which mechanisms. Recent studies suggest that fat accumulation plays a direct role in promoting whole body chronic inflammation. The laboratory of Dr Lamarche has shown previously that DHA is more potent than EPA in reducing some of the blood markers of inflammation in adults at risk of heart disease. In this context, the overarching objective of the present project was to compare and further understand the anti-inflammatory effects of EPA and DHA in men and women at risk of heart disease through innovative physiological and molecular studies.

Work performed

Many experiments and analysis have been performed using biological samples from adults at risk of heart disease. The impact of EPA vs. DHA supplementation was notably investigated through the study of specific inflammation markers in the bloodstream, immune cells and abdominal adipose tissue of the participants, who received in random order approximately 3g of EPA and 3g of DHA in random order for periods of 10 weeks each. The main results achieved so far suggest that (1) the genes that influence inflammation processes in immune cells do not contribute to the distinct anti-inflammatory effects of EPA vs. DHA on plasma markers of inflammation, (2) superficial abdominal adipose tissue does not appear to play a role in explaining the difference between EPA and DHA in modulating chronic inflammation, and (3) the stronger anti-inflammatory effects of DHA compared with EPA may be due, in part, to changes in specific bioactive lipids derived from DHA and EPA. Further mechanistic studies using complex in vivo metabolic studies, which allow the in vivo tracking of inflammatory proteins, are still in progress.

Final results

The project study brings invaluable and timely data, considering that the population is increasingly using DHA and EPA supplements. To that extent, they represent one of the fastest growing market in the dietary supplements’ industry. To date, results of the present project point to specific mechanisms that may explain to the potentially greater anti-inflammatory effects of DHA compared to EPA, although such differences remain small. This work provides new perspectives to pursue in future studies on DHA and EPA. The study of in vivo metabolism of inflammation proteins, which is still in progress, are extremely novel and will undoubtedly be breakthrough in explaining the anti-inflammatory effects of DHA and EPA. End-users of the results from the project study are: 1) scientists (via papers, conferences), 2) the partnered company ATRIUM Innovations, who continues to use the results of this research for future product development and 3) the lay public, in conferences given by various members of the research group on a regular basis. Ultimately, this research may provide new evidence to the government, policy makers, health professionals and patients of the importance and proper use of food supplements as potential contributors to metabolic disease prevention.