Abstract

Polyunsaturated fatty acids (PUFAs) have been used as dietary supplements for quite some time with various health claims. Major dietary PUFAs are classified as omega-3 and omega-6 based on their structure, and these fatty acids are considered essential nutrients. The two classes of PUFAs, although structurally similar, present different biological activities that can be beneficial or detrimental to humans. Some of these biological activities have been known for a long time, while others are emerging from the plethora of dietary studies done on PUFAs. Yet many of the health claims for PUFAs are still debated, with the findings being conflicting. This review summarizes our current knowledge on the biological activities of PUFAs and discusses the dietary sources available. In light of new dietary recommendations, PUFA consumption is on the rise, so new dietary sources for these fatty acids are needed.