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The omega-3 fatty acids, EPA and DHA, have different anti-inflammatory mechanisms

The omega-3 fatty acids, EPA and DHA, have different anti-inflammatory mechanismsIt is well-known that omega-3 fatty acids counteract inflammation, which is the common thread in most chronic diseases. A team of scientists from Tufts University in the United States has now discovered that the omega-3 fatty acids, EPA and DHA, which we get from oily fish and fish oil supplements have different anti-inflammatory mechanisms. Their study is published in the science journal Atherosclerosis and supports earlier studies that have shown how important omega-3 is for preventing circulatory diseases, rheumatism, and other lifestyle diseases.

Omega-3 fatty acids are essential and we need them from our diet. Our cell membranes contain the two omega-3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), that both have a list of different physiological functions. Oily fish and fish oil supplements have a high content of EPA and DHA. These omega-3 fatty work in an intricate biochemical interplay with the omega-6 fatty acids. It is important to get these fatty acids in the right quantity and the correct ratio. If we get too little omega-3, it sets the stage for chronic inflammation and other imbalances. Chronic low-grade inflammation is not something we notice or feel, yet it is involved in ageing processes, cardiovascular ailments, type 2 diabetes, depression, Alzheimer’s disease, and cancer. More serious inflammation that causes tissue damage is involved in autoimmune diseases like rheumatoid arthritis. Over the past decades, the rate of inflammatory diseases has increased drastically due to changes in our diet and lifestyle.

Controlling inflammation

The body must be able to initiate acute inflammation to fight infections and tissue damage. However, it is vital for the immune defense not to overreact and make the inflammation chronic because this increases the risk of different diseases. This is because chronic inflammation generates massive amounts of free radicals, which are aggressive and harmful molecules that make chain reactions in and around the cells. Free radicals can also oxidize cholesterol, which starts off the process known as atherosclerosis.
The body’s inflammatory processes are controlled by different proteins that are produced by certain white blood cells. It is important always to have the right balance between pro-inflammatory and anti-inflammatory proteins.
The Tufts University science team observed that DHA had a greater anti-inflammatory effect than EPA. Moreover, DHA lowered levels of a certain anti-inflammatory protein. Then again, EPA was better than DHA at restoring the proper balance between pro- and anti-inflammatory cytokines. In the prevention of cardiovascular disease, it is essential to have the right balance between pro-inflammatory and anti-inflammatory proteins. This is also relevant in connection with overweight, accompanying diseases like type 2 diabetes, and many other chronic ailments.
Both EPA and DHA are believed to function as “starter molecules” that initiate the production of anti-inflammatory proteins. But they are also able to block the formation of pro-inflammatory proteins.
According to a review article, EPA and DHA supplements significantly reduce several pro-inflammatory proteins such as C-reactive protein (CRP), TNFα (tumor necrosis factor alpha), and IL-6 (interleukin-6).
A study published in 2018 has demonstrated that high doses of EPA and DHA are able to reduce blood levels of both IL-6 and IL-1β.

Study details

The new study from Tufts University lasted 36 weeks and included nine men and 12 menopausal women. The participants were aged 50-75 yeas and had all been diagnosed with chronic inflammation. To begin with, all subjects were given supplements of sunflower oil that contains omega-6. That way, the participants were comparable. After that, they got supplements of either EPA or DHA.
Besides finding that DHA had anti-inflammatory properties, the scientists saw that DHA reduced a genetic tendency to form four pro-inflammatory proteins, while EPA was only able to reduce one type. On the other hand, EPA had other abilities in terms of regulating the immune response.
Although it appears that DHA has the most potent anti-inflammatory effects, the scientists say that the final word has not been said. It is therefore a good idea to get both EPA and DHA and you can get these essential fatty acids from oily fish or from supplements.
Just for the record, it takes around a month for EPA and DHA to get properly embedded in the cell membranes, so this is how long you should wait before you can expect to notice an effect. If you stop taking fish oil, on the other hand, you must also be prepared to allow a month to pass before the effect wears off. This sometimes makes it difficult for people to see that their fish oil intake has an effect on their condition.

How much EPA and DHA do we need?

If you follow the official dietary guidelines for fish intake by eating 200-300 grams of fish (primarily from oily fish), you should be okay. Still, the average fish consumption has decreased over the past decades and the daily intake of EPA and DHA is only around 0.2 grams, which is far too little

International experts recommend the following daily fish oil intake:

  • 500 mg to prevent an actual deficiency
  • 1 gram as proactive support of e.g. heart and cardiovascular system
  • 2-4 grams for intensive support of e.g. aching joints and inflammation

The need for omega-3 fatty acids may vary from person to person. If you dislike the taste of fish or simply eat too little, a fish oil supplement is a useful alternative. Fish oils based on free fatty acids give better bioavailability. Also make sure that your fish oil supplement is within the safety threshold with regard to peroxide value and environmental toxin content.

How much omega-3 is there in oily fish?

There is about one gram of omega-3 in a herring fillet and 3-4 grams in a wild salmon steak.


Jisun So et al. EPA and DHA differentially modulate monocyte inflammatory response in subjects with chronic inflammation in part via plasma specialized pro-resolving lipid mediators: A randomized, double-blind, crossover study. Atherosclerosis. January 01, 2021

Will Chu. Omega-3 oils EPA and DHA differ in actions that tackle inflammation: Study. 08-Dec-2020

The Norwegian University of Science and Technology (NTNU). Understanding how omega-3 dampens inflammatory reactions. ScienceDaily 2017

Understanding How Omega 3 Dampens Inflammatory Reactions Neuroscience News 2017

Abdulrazaq, Innes JK, Calder PC. Effect of ω-3 polyunsaturated fatty acids on arthritic pain: A systematic review. Nutrition 2017

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