What are essential fatty acids?
Essential fatty acids are polyunsaturated fatty acids that the human body cannot synthesise and that therefore have to be supplied by food. In humans these are linoleic acid (omega-6) and alpha-linolenic acid (omega-3), the parent compounds of all longer-chain omega-6 and omega-3 fatty acids.
What does “essential” mean?
“Essential” means vital and not producible by the body. Humans lack the Δ12 and Δ15 desaturases needed to insert double bonds beyond position 9 (counted from the carboxyl end) of the fatty acid chain, so the two parent fatty acids must come from food:
- Linoleic acid (LA): an omega-6 fatty acid found in sunflower, safflower, soybean and corn oil as well as nuts and seeds.
- Alpha-linolenic acid (ALA): an omega-3 fatty acid found in linseed oil, chia, walnuts and rapeseed oil.
From both, the body can build longer-chain fatty acids, including arachidonic acid from linoleic acid and EPA and DHA from alpha-linolenic acid. Because this conversion is low for omega-3, EPA and DHA are often discussed as “conditionally essential”.
Intake values and authorised claims
Adequate intake according to EFSA and EU claims.
| Fatty acid | Adequate intake (EFSA) | Authorised EU claim |
|---|---|---|
| Fatty acid Linoleic acid (omega-6) | Adequate intake (EFSA) 4 % of total energy | Authorised EU claim contributes to normal blood cholesterol at 10 g per day |
| Fatty acid Alpha-linolenic acid (omega-3) | Adequate intake (EFSA) 0.5 % of total energy | Authorised EU claim contributes to normal blood cholesterol at 2 g per day |
| Fatty acid EPA + DHA | Adequate intake (EFSA) 250 mg per day | Authorised EU claim contributes to normal heart function at 250 mg per day |
Common misconceptions
- “Omega-6 is bad.” No, linoleic acid is essential. What counts is a balanced overall intake.
- “Essential means you need a supplement.” No. Most people cover their needs for essential fatty acids through a normal diet. For EPA and DHA it is worth looking at your fish intake: the German Nutrition Society recommends fish once or twice a week, including at least one portion of fatty sea fish.
- Essential fatty acids and essential amino acids are different groups of nutrients, but the principle is the same.