Polyunsaturated fatty acids (PUFAs) can be classified as omega-3, omega-6 or omega-9 fatty acids depending on the position of the double bond closest to the methyl end. The most common PUFAs are alpha-linolenic acid (ALA), linoleic acid (LA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). PUFAs play important roles in membrane fluidity, eicosanoid production, and modulating the immune system. DHA in particular may reduce inflammation by decreasing NF-kB activation and cytokine production.