What are eicosanoids and why they are so important?

Eicosanoids were the first hormones developed by living organisms more than 550 million years ago. They control the hormonal actions of other hormones. The word eicosanoids is derived from the Greek word for 20 which is eicosa, since all of these hormones are synthesized from essential fatty acids that are 20 carbon atoms in length.  They were identified in the 20th century starting with the discovery of essential fatty acids in 1929.

Researchers realized that essential fats were composed of both Omega-6 and Omega-3 fatty acids that both needed to be obtained in the diet because the body could not synthesize them.

The first actual eicosanoids which were discovered in 1935 were isolated from the prostate gland and were called prostaglandins. Later, researchers found that every living cell in the body could make eicosanoids, and that there was no discrete organ or gland that was the center of eicosanoid synthesis.