From Chapter 10: Where Have All The Omega-3s Gone?
Perhaps the most interesting perspective on how diets have been changing comes from a research tack taken by Artemis Simopoulos after the 1985 conference [chaired by Simopoulos on the role of fatty acids in the human diet]. The food tables that were available at the time of the conference listed the content of very few green vegetables. But those figures — for spinach, leeks, lettuce, kale, and broccoli — were surprising to Simopoulos.
These green leafy vegetables, it appeared, have significant amounts of fat. Not as much fat as seeds, grains, or the flesh of fish and fowl, certainly, but more fat than most people would have ever expected. And what fats they do have are mostly alpha linolenic acid, from the omega-3 family.