Omega-3 Fatty Acids

epa dha ala

Important omega-3 fatty acids in nutrition are: α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). The human body cannot synthesize omega-3 fatty acids
de novo, but can synthesize all the other necessary omega-3 fatty acids from the simpler omega-3 fatty acid α-linolenic acid that can be obtained from food.

Alpha-linolenic acid (ALA)

We usally get enough ALA from diet, like nuts, flax seed, canola, soybean oil.
Alpha-linolenic acid is an essential polyunsaturated fatty acids. It is the building block of EPA and DHA and thus the anti-inflammatory eicosanoids like PGE3 and LTB5. (see
"Metabolic Pathway of Essential Fatty Acids").

Eicosapentanoic acid (EPA) and Doxosahexanoic acid (DHA)

Through a series of metabolic steps, ALA is converted to two other important omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, this process is usually slow, only a maximum of 15% of ALA ingested will be converted to EPA and even less, to DHA.

The following lifestyle and health problems may also influence or inhibit the conversion :

  • High consumption of LA (Omega-6), saturated fat and trans-fat
  • Smoking, stress, excessive intake of sugar or alcohol
  • Diabetes, heart diseases, immune dysfunction, metabolic syndrome
  • Deficiency of vitamins and minerals (e.g. vitamin B3, B6, C, zinc, and magnesium)

Therefore, it is not recommended to rely ALA as the source of EPA and DHA.

Fish high in omega-3 fatty acids include salmon, mackerel, blueling, herring,sardines and tuna etc. Other marine life, such as krill and algae, also contain omega-3s. For non-fish lovers, fish oil supplements are a good alternatives for DHA and EPA. blue ling fish
Blue Ling Fish

Benefits of EPA & DHA

DHA and EPA allow the central nervous system to develop properly and play a role in vision and brain development.

Through conversion to anti-inflammatory eicosanoids, DHA and EPA reduce inflammation, and help balance bad / good lipids. They also play a role in reducing blood aggregation and promote cardiovascular health. (See "Fish Oil and Fish Peptides" for more details.)

Side effects of EPA & DHA Fish Oil
Taking too much fish oil will lead to problems like excess caloric intake, stomach & gastrointestinal upset and increased risk of bleeding.(See "Fish Oil and Fish Peptides" for more details.)