How do Omega-3 fatty acids work ?

How do Omega-3 fatty acids work

How do Omega-3 fatty acids work?

Do Omega-3 supplementation reduce the risk of heart disease and stroke ?

Let’s start by taking a look at the history and action of the supplement. How do Omega-3 fatty acids work ?

This article is based on two review articles, One published in the European Heart Journal in 2012 and one published in Current Cardiovascular Risk Rep in 2014.

Essential fatty acids were discovered way back in 1929. Certain fatty acids couldn’t be produced in the human body, they had to be ingested in the diet in order to be put to use. These essential fatty acids, belong to the class of fatty acids called omega-3, which can be found in fish oil. Omega-3 acids are a group of polyunsaturated fatty acids, three of the fatty acids are involved in processes in the human body: alpha linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

As early as 1937 researchers were concerned that a lack of essential fatty acids could cause heart disease which triggered scientific research into diets containing high levels of essential fatty acids and their effect on health. A study conducted on the Inuit people who’s diet contained more than 4 times as much Omega-3 as people living in a western country found that Inuit rate of heart attacks were 10 times lower, an astounding find. The rarity of heart disease together with experiments changing diets to the Inuit one led to studies in the 1980s ,in which, researchers added fatty fish to the diet of patients affected by coronary heart disease. The dietary changes had an effect, a reduction in deaths caused by coronary artery diseases. These scientific studies lead to an increase in interest into omega-3 fatty acids and how they could be used to reduce the risk of and improve outcomes of heart disease.

How do Omega-3 fatty acids work ?

So how do omega-3 fatty acids work ? The easy answer is that it influences different systems in the body affecting inflammation, coagulation and blood vessel function.


Omega-3 lowers the amount of arachidonic acid (AA) on the surface of cell membranes of several types of cells including endothelial cells, platelets and immune cells.  This reduction is important since the body uses this acid to make pro-inflammatory molecules and signal molecules, a lack of AA means less inflammation. Omega-3 can also reduce key signals in the inflammatory response lowering inflammation even further.

Blood Thinning

Omega-3 also thins the blood. The fatty acids prevent platelets from clumping together reducing the risk of blood clots, a key aspect of artery disease. It also reduces levels of “bad cholesterol” and remnant lipoproteins, both risk factors of heart disease. This blood-thinning effect was experienced first hand by a researcher testing an Inuit diet for 100 days, as it increased his bleeding time (time it takes for the blood to clot) from 3-5 min to 50 min.

Affecting Blood Vessels

In addition Omega-3 fatty acids can improve the function of the innermost layer of cells in blood vessels, the endothelium. EPA an omega-3 fatty acid can help relax arteries on the heart reducing the risk of blockage by atherosclerotic plaques. Increasing the tissue levels of DHA and EPA stabilize atherosclerotic plaques, reducing infiltration of immune cells and thickening of the fibrous cap on these plaques. In addition to these beneficial effects Omega-3 fatty acids also incorporate themselves into heart muscle cells stabilizing heart rhythm lowering the risk of tachyarrythmias, a potentially fatal heart rhythm.

All of these beneficial effects have been observed in studies on Omega-3 either in animals, people or in lab tests. But are these effects strong enough to prevent disease? Is there a significant decrease in heart disease, or deaths caused by heart disease, in people eating a lot of fish or taking Omega-3 supplements? Find out in part two

Image Credit: Jo Christian Oterhals via, CC BY-NC-ND 2.0