Recent omega-3 studies are ‘leap forward’ from population information to RCTs

15-May-2017 - Last updated on 16-May-2017 at 15:48 GMT

EPA and DHA omega-3 fatty acids both drive anti-inflammatory gene expression, while DHA is better at lowering triglycerides and decreasing inflammatory markers, according to recent studies that are said to be a “leap forward” in our understanding.

Data published in the Atherosclerosis indicated that high dose EPA (eicosapentaenoic acid) or DHA (docosahexaenoic acid) supplementation produced similar effects on gene expression in immune cells in men and women. However, data published in the American Journal of Clinical Nutrition showed that there was a difference when it came to decreasing inflammatory markers such as C-reactive protein (CRP) and interleukin-18 (IL-18), with DHA producing better results than EPA.

A third study, published in Prostaglandins, Leukotrienes and Essential Fatty Acids,found that high dose DHA (2.7 grams per day) increased the Omega-3 Index by an average of 5.6%, which was greater than the 3.3% increase observed following consumption of EPA (2.7 grams per day). All three studies were performed by scientists at Laval University's Institute of Nutrition and Functional Foods (INAF) and supported by Atrium Innovations.

“Together, these studies mark an important shift from epidemiological research to well-designed intervention studies that tease apart the true benefits of EPA and DHA fish oil supplementation,” said Barry Ritz, PhD, chief scientific officer and VP of professional R&D and regulatory, Atrium Innovations Inc.

“These findings contribute to the larger conversation on how fish oil can be used most effectively as a clinical tool in the promotion of health and the management of chronic disease. Fish oil supplements are popular, and this is an intriguing area of research, so it is important that practitioners and patients alike continue to follow the developments in this particular area of research in the coming years.”

Partnership with INAF

The recent papers are the culmination of the work that started with INAF at Laval in 2011, explained Dr Ritz in a telephone interview. “We’ve always been engaged in research but there seemed to be an opportunity with INAF to establish a relationship and tackle some key academic questions in a comprehensive way,” he added.

Atrium’s interest was around cardiometabolic health, and the link between inflammation and cardiometabolic health is an area where nutrition would be expected to play a significant role, said Dr Ritz.

This led to three major projects with Laval:
1. Fish oil and differentiation between EPA and DHA
2. Polyphenols
3. Systemic enzymes related to Wobenzym

Fish oil benefits

The findings of the three studies fill a void in available research by specifically evaluating the mechanisms by which long-chain PUFAs influence health and contribute to disease prevention, said the company.

Ten weeks of supplementation with 2.7 grams per day of either EPA or DHA (Douglas Laboratories) indicated that DHA produced significantly greater reduction in IL-18 levels, triglyceride levels. DHA also increased HDL levels more than EPA (American Journal of Clinical Nutrition).

When the researchers looked at the expression of genes involved in regulating anti- and pro-inflammatory processes they found that EPA and DHA has similar effects, with key roles identified for PPARA and TRAF3

“To the best of our knowledge, this is the first study comparing the impact of EPA (2.7 g/d) and DHA (2.7 g/d) supplementation on inflammatory gene expression in whole blood cells,” wrote the researchers in Atherosclerosis.

“The CRP reduction observed with DHA compared to the control treatment was more strongly correlated with up-regulation of anti-inflammatory gene expression than with down-regulation of pro-inflammatory genes.”

Omega-3 Index

The final study, published in this month’s edition of Prostaglandins, Leukotrienes and Essential Fatty Acids, found that the Omega-3 Index (O3I) of participants in the DHA group increased by an average of 5.6%, compared with a 3.3% increase in the EPA group.

In addition, the researchers observed potential gender differences, with a greater O3I increase in men than in women.

“A high O3I, which reflects a relatively high content of EPA and DHA in the membranes of [red blood cells], has been associated with a lower risk of CHD [coronary heart disease] and mortality in observational studies,” explained the scientists.

“The increase in the O3I is greater with high dose DHA supplementation than with high dose EPA, which is consistent with the greater potency of DHA to modulate cardiometabolic risk factors.”

Atrium continues to work with other partners to investigate health benefits associated with omega-3 fatty acids, with work on-going around the cross-over of people with cardiovascular disease and depression, said Dr Ritz.

Sources:
Atherosclerosis
February 2017, Volume 257, Pages 116–122, doi: 10.1016/j.atherosclerosis.2017.01.025
“Inflammatory gene expression in whole blood cells after EPA vs. DHA supplementation: Results from the ComparED study”
Authors: C. Vors et al.

American Journal of Clinical Nutrition
August 2016 , Volume 104, Number 2, Pages 280-287, doi: 10.3945/ajcn.116.131896
“A randomized, crossover, head-to-head comparison of eicosapentaenoic acid and docosahexaenoic acid supplementation to reduce inflammation markers in men and women: the Comparing EPA to DHA (ComparED) Study”
Authors: J. Allaire et al.

Prostaglandins, Leukotrienes and Essential Fatty Acids
May 2017, Volume 120, Pages 8-14, doi: 10.1016/j.plefa.2017.03.008
“Supplementation with high-dose docosahexaenoic acid increases the Omega-3 Index more than high-dose eicosapentaenoic acid”
Authors: J. Allaire et al.