In the strictest sense, there are only two essential fatty acids in human nutrition- alpha-linolenic acid (ALA) and linoleic acid (LA). ALA and LA are required in our diet because our bodies cannot make them. For this reason, ALA and LA are essential nutrients just like calcium, potassium, vitamin C and folate.

The long-chain fatty acids derived from ALA and LA are not essential because the body can make them from ALA and LA. Nonetheless, the long-chain fatty acids in the omega-3 family and many in the omega-6 family are called “essential” in the medical literature because their importance in maintaining health and preventing disease is widely recognized.

Diane H. Morris, PhD
Flax A Health and Nutrition Primer