Effects of Omega-3 Fatty Acids on the Human Gene Expression

• Gene Expression Changes [ Time Frame: Gene expression changes (number of regulated genes) ] [ Designated as safety issue: No ]
  Gene expression changes were measured by using whole genome microarrays. The expression values of all genes were compared between baseline and 4 hours, 7 days and twelve weeks after supplementation with FO or CO and differentially expressed genes were detected by standard two-state pooled-variance t-test (p<0,05). The number of differentially expressed genes (regulated genes)compared to the baseline values were determined for every study group in total as well as for every time point (4 hours, 7 days, 12 weeks)in total and specifically.
  
  

• Fatty Acid Composition of Erythrocyte Membranes (Omega-3 Index) [ Time Frame: baseline and after 12 weeks ] [ Designated as safety issue: No ]
  Fasting venous blood samples were collected and RBC membrane FA composition including the omega-3 index, given as EPA + DHA, was analyzed at baseline and after 12 weeks according to the omega-3 index methodology (Harris & von Schacky, 2004). Results are presented as a percentage of the total identified FAs after response factor correction. The coefficient of variation for EPA + DHA was 5%. Quality was assured according to DIN ISO 15189.
  
  
• Blood Lipids [ Time Frame: baseline and after 12 weeks ] [ Designated as safety issue: No ]
  Fasting venous blood samples were collected and blood lipid levels were determined by an external contract laboratory (LADR, Hannover; Germany) at baseline (t0), after one week (t1) and after 12 weeks (t12) of supplementation.
  
  

Cardiovascular and coronary heart diseases continue to be the leading causes of morbidity and mortality among adults in Europe and North America. Since the number of elderly people and therefore the number of chronic-inflammatory diseases rise, preventive therapies become more important. Within preventive strategies, nutrition plays a central role.

Cross-sectional studies suggested that omega-3 fatty acids, especially the very long-chain fatty acids Eicosapentaenoic acid (EPA, C20:5ω3) and Docosahexaenoic acid (DHA, C22:6ω3), are protective against cardiovascular and coronary heart diseases. Their cardio protective potential is based on their positive effects on blood lipids, vascular tonus and blood clotting. A number of controlled clinical trials have shown that EPA and DHA supplementation lower fasting and postprandial plasma concentrations of triglyceride-rich lipoproteins and their remnants. Biochemical research revealed numerous metabolic effects of EPA and DHA, ranging from their effects on membrane fluidity to the modification of the eicosanoid profile.

However, only a few human clinical trials examined the regulative effects of DHA and EPA supplementation on gene expression. Furthermore, to our knowledge no published research data is available dealing with the effect of these fatty acids on gene expression in subjects with hypertriglyceridemia in comparison to healthy subjects. Such findings are of great concern due to hints that especially people with hypertriglyceridemia benefit from the triglyceride lowering effect of EPA and DHA supplementation. Presently it is not well-established if the gene regulative potential of EPA and DHA in these persons differs from healthy persons. These findings could help to understand the differences in the metabolic effects of EPA and DHA in healthy vs. hypertriglyceridemic persons, which have a greater risk for cardiovascular and coronary diseases. Finally, these data could contribute to a knowledge basis for targeted strategies in preventive therapies with the very long-chain omega-3 fatty acids EPA and DHA.