Omega 3 in Human Nutrition: Benefits of EPA and DHA Essential Fatty Acids

What Are Omega 3 Fatty Acids?

Omega 3 fatty acids are a group of polyunsaturated fatty acids. This type of molecule has more than one double bond in its structure. Omega 3 is considered an essential fatty acid. The body needs this molecule for several functions, but it can't synthesize it. So, the only way to acquire this fatty acid is through the diet.

There are three types of omega 3 fatty acids that are nutritionally important. Alpha-linolenic acid (ALA) is the primary omega 3 fatty acid. It is found in several foods. This molecule is broken down into eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These two fatty acids are also present in many foods.

Food Sources

There are several foods that contain EPA, DHA and ALA. Flaxseed, salmon and walnuts contain the highest concentration of omega 3. One serving size of any of these foods meets nearly all of the recommended daily requirement. Other sources that contain slightly less, yet still abundant amounts, include sardines, boiled cauliflower, dried cloves and mustard seeds. Shrimp, kale, raw tofu and raspberries are a few more foods that contain some omega 3.

Recommended Daily Intake

According to the 'Workshop on the Essentiality of and Recommended Dietary Intakes (RDI) for Omega-6 and Omega-3 Fatty Acids', the daily intake of ALA should be about 1 percent of the total calories consumed. This is about 2.2 grams of ALA for a 2,000 calorie diet. The combined daily intake of EPA and DHA should be about 0.65 grams for a 2,000 calorie diet. One serving of flaxseed, which is 2 tablespoons, contains about 3.51 grams. A 4 ounce serving of baked salmon contains about 2.09 grams.

Benefits of ALA, EPA and DHA

There are several benefits of omega 3. At the cellular level, it increase the fluidity of cell membranes. It also promotes the production of beneficial prostaglandins that reduce clotting and inflammation, and increase blood flow. Omega 3 plays a role in brain function and development.

A lack of omega 3 in the diet can lead to several symptoms. Fatigue, difficulty concentrating, lack of endurance and dry skin are a few signs of this fatty acid deficiency.

Conditions That May Improve with Omega 3

Consuming the recommended daily amount of omega 3 may reduce blood pressure, lower triglyceride levels, lower apoprotein levels and increase HDL or good cholesterol. Those with diabetes and heart disease would benefit from these effects. Fish oil, which contains omega 3, may relieve some of the symptoms associated with rheumatoid arthritis. Omega 3 in human nutrition may reduce the risk of developing other conditions including depression and some types of cancer.

References

1. "Omega-3 Fatty Acids." University of Maryland Medical Center. https://www.umm.edu/altmed/articles/omega-3-000316.htm

2. "Omega-3 Fatty Acids." WHFoods. https://www.whfoods.com/genpage.php?tname=nutrient&dbid=84

3. "Workshop on the Essentiality of and Recommended Dietary Intakes (RDI) for Omega-6 and Omega-3 Fatty Acids." Journal of the American College of Nutrition. https://www.jacn.org/content/18/5/487.full.pdf