These fatty acids likely activate FFA1, inducing an intracellular response.[12] It has been found that docosahexaenoic acid (DHA) has a higher affinity than other fatty acids for FFA1.[2] DHA makes up 30% and arachidonic acid, another fatty acid found in the brain, makes up 20% of the fatty acids in the brain.[12] Both of these fatty acids must be obtained from the diet because the body cannot make them.