EFAs are the building blocks of the membranes of all of the some 50 trillion cells in an average adult. Every second of every day billions of human cells are constantly dying and being re-born. These are cells that make up your skin, organs, hair and bones. With the exception of the brain, every cell in the body is being constantly renewed.

EFAs are substances from fats that must be provided by foods because the body cannot make them itself. They exist in three families: omega-3 (n-3), omega-6 (n-6) and omega-9 (n-9). From these the body can make several derivatives, as well as eicosanoid 'hormones', and other active substances essential for maintenance of all human cellular activity. Failure to eat enough EFAs is a cause of hardening of the arteries, abnormal blood clot formation, coronary heart disease, high cholesterol, and high blood pressure.