DHA is more effective than EPA in increasing the Omega-3 Index and reducing inflammation and triglycerides

Omega-3 DHA reduces inflammation and high triglycerides!

The omega-3 supplements EPA and DHA act with equal effectiveness on cells of the immune system by similarly regulating the expression of specific genes involved in inflammation. DHA, on the other hand, exerts a greater effect than EPA in reducing blood triglycerides and certain signal molecules of the inflammatory state, and has a better ability to increase the Omega-3 Index, thus reducing cardiac risk.

These are the results of three different studies conducted by a team of researchers from the Institute of Nutrition and Functional Foods at Laval University (Canada), and published in the scientific journals Atheroclerosis, American Journal of Clinical Nutrition and Prostaglandins, Leukotrienes and Essential Fatty Acids.

Omega-3 anti-inflammatory and cardiovascular health effects

Omega-3s are a category of fatty acids particularly known for their positive effects on the body at different stages of life. Various types of omega-3s exist in nature including the plant-derived, eighteen-carbon-atom alpha linolenic acid and the long-chain omega-3s, EPA and DHA. Vegetable oils such as flaxseed oil, Canola oil, and some types of nuts contain mainly linoleic acid. 

Instead, the major dietary sources of EPA and DHA are fish, especially those that inhabit cold seas. Omega-3s can also be consumed in the form of dietary supplements, formulated with fish oil extracts, which contain a varying ratio in EPA and DHA. There are numerous research studies conducted to determine the association between omega-3 consumption and cardiovascular risk reduction. 

Indeed, they modulate a variety of factors, such as blood lipid concentration, blood pressure, thrombosis, and inflammation, which can increase the likelihood of cardiovascular disorders. Inflammation is also a feature of chronic conditions, such as obesity, metabolic syndrome, and type 2 diabetes mellitus, and is a key factor in the development of atherosclerosis and thus ischemic heart disease. 

There is a considerable amount of scientific research suggesting how many foods and nutrients, and in particular omega-3s, modulate the chronic inflammatory state observed in cardiometabolic diseases. In particular, EPA and DHA exert their anti-inflammatory effect by altering the properties and function of immune cells by modifying the expression of specific genes. However, almost all research on the anti-inflammatory effects of omega-3s published to date refers to a mixture of EPA and DHA or just one of the two. Emerging studies suggest, however, that EPA and DHA exert different effects on blood lipid concentration and markers of inflammation, but, such evidence is limited and little has been discovered about the specific effects of the two omega-3s on metabolic pathways and biological processes underlying cardiac and metabolic health in humans. 

The fatty acid composition of cell membranes influences their physicochemical properties, and omega-3s also become part of cell membranes, affecting their fluidity, structure and function. The Omega-3 index, calculated as the percentage content of EPA and DHA in red blood cell membranes reflects the fatty acid composition of major organs, including the heart. 

A high Omega-3 Index (8-12%) has been associated with a lower risk of coronary artery disease and coronary mortality. In fact, the use of EPA and DHA supplements is recommended by various health agencies including the American Heart Association for secondary prevention of cardiovascular disorders or management of plasma triglycerides. 

However, whether EPA and DHA have a distinct effect on the Omega-3 Index is currently unknown. Considering that the Omega-3 Index is modifiable by diet, studies are needed to compare the different effects of EPA and DHA on this clinical tool for cardiovascular risk management. The aim of the Raval University researchers was precisely to investigate the different effects of EPA and DHA, in men and women.

DHA is more effective on inflammatory molecules, blood lipids and Omega-3 Index

Research data indicated that high doses of EPA or DHA produce similar effects on immune cell gene expression, in men and women, thus reducing symptoms of inflammation equally. However, a second research showed a difference in the effects of the two omega-3s on signal molecules of inflammation, so-called inflammatory markers, such as C-reactive protein (CRP) and interleukin-18 (IL-18); highlighting the greater ability of DHA to reduce these molecules compared with the same amounts of EPA. DHA was also found to be more potent in modulating blood lipid concentrations. 

The third study, published in Prostaglandins, Leukotrienes and Essential Fatty Acids, found that high daily amounts of DHA, increased the Omega-3 Index by an average of 5.6 percent, a greater increase than that achieved with the same amount of EPA. According to the researchers, DHA's greater ability to increase the Omega-3 Index than EPA is consistent with DHA's potency in modulating cardiometabolic risk factors. "Taken together, all of these studies mark an important shift from epidemiological research to intervention studies that highlight the benefits of fish oil supplements," said Barry Ritz, researcher for the company that financially supported the three studies. 

"The findings contribute to the great debate about how fish oil can be used effectively as a clinical tool in health promotion and chronic disease management. Omega-3 supplements are, in fact, very popular and widespread, so it is important for health professionals and patients to follow developments in this area of research in the coming years," Ritz continued.

Some details of the research

A total of 154 subjects, 48 men and 106 women, with abdominal obesity and low-grade inflammation were involved in the research. One group followed daily supplementation with 2.7 grams of EPA, a second group with the same amount of DHA, and a third consumed only corn oil as a control. 

After 10 weeks of treatment, the researchers analyzed the amount of inflammation signal molecules, triglycerides and cholesterol for each person. They also studied gene expression in immune cells and determined the Omega-3 Index. The results showed that while high-dose EPA or DHA supplementation had similar effects on the expression of many inflammation-related genes in immune cells of individuals at risk for cardiometabolic diseases, DHA was shown to be more effective in reducing levels of IL-18, CRP, triglycerides and cholesterol. 

In addition, the Omega-3 Index of participants in the group that had received DHA had increased by an average of 5.6 percent, compared with 3.3 percent in the EPA group, with a greater increase in men than in women.

DHA reduces inflammatory molecules and increases Omega-3 Index more than EPA

According to the researchers who conducted them, the results of the three studies fill a gap in research having assessed the specific effects by which omega-3s contribute to the health and prevention of important metabolic diseases. In fact, these are the first studies to efficiently compare the effects of EPA and DHA on markers of inflammation and blood lipids, and thus on cardiovascular risk in men and women with abdominal obesity and systemic inflammation, demonstrating the greater efficacy of DHA compared with EPA.

Omegor VitaDHA liquid: a supplement rich in DHA

The right amount of DHA can be consumed with VitaDHA liquid; a supplement produced by Omegor with purified fish oil, which contains as much as 1450 mg of DHA 330 mg of EPA in each vial. It is indicated in all conditions where increased DHA intake is required. To stay up-to-date on the latest news from Omega-3 scientific research, sign up for our newsletter.