Walnuts are high in polyunsaturated fats (66%, 24% monounsaturated and 10% saturated) and are considered a good source for Omega-3 fatty acids. The problem is they are higher in Omega-6 fatty acids. Both are essential fatty acids you need to include as part of a healthy diet. The problem lies in that the average North American diet contains way too much Omega-6 and this can lead to chronic health problems because Omega-6 fatty acids are inflammatory, which have a negative long term effect on your system, and need the Omega-3 fatty acids, which are anti inflammatory, to balance them out. The average diet contains a ratio of 20:1 Omega 6 to 3 where the ideal ratio should be 4:1, or in an ideal world, 1:1. So what gives with walnuts? The ratio of Omega-6 to 3 is 4:1, so in my view the Omega-3 is cancelled out by the high Omega-6 count. While walnuts provide other health benefits, if you’re looking to improve your Omega-3 intake, your better choice would be milled flax or flax oil, which are almost exclusively Omega-3, and fish and fish oil supplements.