Fat chance for longevity.

The health benefits of specific fatty acids and physiological roles of fat metabolism are important subjects that are still poorly understood. In this issue of Genes & Development, O'Rourke and colleagues (pp. 429-440) uncovered a role for lipase-generated ω-6 fatty acids in promoting autophagy and, consequently, life span extension under both fed and fasting conditions. The impact of this finding is discussed with regard to the nutritional value of ω-6 fatty acids and regulatory functions of fat metabolism beyond its well-known role in energy storage.