Between 1930 and 1950, arachidonic acid and linolenic acid were termed 'essential' because each was more or less able to meet the growth requirements of rats given fat-free diets.
Entre 1930 e 1950, o ácido araquidónico e o ácido linolénico eran considerados "esenciais" porque basicamente tiñan a capacidade de fornecer os requirimentos para o crecemento das ratas que recibían dietas carentes de graxas.