Alpha-linolenic acid: a gift from the land?

Although the fish-derived, long-chain omega-3 fatty acids (n-3 FA) may be considered “gifts from the sea” for cardiovascular health, the role of the land (or plant) -based n-3 FA -linolenic acid (ALA) has been less clear. ALA is the 18-carbon, 3-double bond (C18:3n-3) precursor to eicosapentaenoic acid (EPA; C20:5n-3) and docosahexaenoic acid (DHA; C22:6n-3), the latter 2 being the predominant n-3 FA in fish oils. ALA is found in certain plant oils, most notably flaxseed oil (where it constitutes 50% of total FA) and in canola oil ( 9%), unhydrogenated soybean (salad dressing) oil ( 7%), hydrogenated soybean oil ( 3%), and olive oil ( 1%). According to National Health and Nutrition Examination Survey (NHANES) III data, consumption in the United States currently averages 1.3 g/d.