" In 1929 George and Mildred Burr published a paper claiming that unsaturated fats, and specifically linoleic acid, were essential to prevent a particular disease involving dandruff, dermatitis, slowed growth, sterility, and fatal kidney degeneration.
In 1929, most of the B vitamins and essential trace minerals were unknown to nutritionists. The symptoms the Burrs saw are easily produced by deficiencies of the vitamins and minerals that they didn't know about.
What really happens to animals when the "essential fatty acids" are lacking, in an otherwise adequate diet?
Their metabolic rate is very high.
Their nutritional needs are increased.
They are very resistant to many of the common causes of sickness and death.
They are resistant to the biochemical and cellular changes seen in aging, dementia, autoimmunity, and the main types of inflammation.
The amount of polyunsaturated fatty acids often said to be essential (Holman, 1981) is approximately the amount required to significantly increase the incidence of cancer, and very careful food selection is needed for a diet that provides a lower amount."