There's one basic reason why you read and hear so much about the essential Omega-3 Fatty Acids these days. Back in the early 1980s nutritional scientists figured out that the balance of Omega-6 and Omega-3 fatty acids in animal bodies had a dynamic impact on the health of animals. After numerous experiments and observations they determined that the optimal fatty acid balance by weight in the membranes of cells turns out to be one to one -- Omega-6 to Omega-3. They also noted that grain, grain-based foods, grain-fed livestock products, nuts, most seeds, and many fruits are deficient in the critically important Omega-3 Fatty Acid compared to the Omega-6 fatty acid load. Therefore they correctly concluded that the Omega-3 Fatty Acid deficiency was caused by grain and other seasonal foods made plentiful by modern agriculture because the balance of essential fatty acids in them is way out of whack with animal body requirements
The imbalance of Omega-6 out weighing the Omega-3 in cell membranes is interpreted as a deficiency of Omega-3s in animal (and human) bodies. This imbalance leads to body failures. Body failures are called chronic diseases. Consequently, all chronic diseases can be traced to eating grain, grain-based foods, grain-fed livestock products, nuts, most seeds, and many fruits! (Also, high glycemic foods are very dangerous.) Unfortunately, whenever you read or hear about the Omega-3 Fatty Acids rarely are you told about fatty acid imbalances and that most of our nation's food staples are the actual source of the problem. This disconnect is one of the great travesties of the modern information age.