Are there any recent articles on conversion efficiency?


Dear RP,

Dr. Graham Burdge has reviewed the published studies wherein the conversion efficiency of alpha-linolenic acid (LNA) to the long chain omega-3 fatty acids including DHA and EPA have been studied in humans using tagged (deuterated) LNA as the ingested precursor fatty acid (Current Opinion in Clin. Nutr. Metab. Care, 7: 137-144 (2004)). In their studies as published, Dr. Burdge and colleagues reported a non-detectable conversion of LNA to DHA in men over a 21 day period whereas a 9% apparent conversion was observed in women. The combined apparent conversion of LNA to EPA +DHA was estimated to be approximately 8% in males (as EPA with the DHA being non-detectable) and approximately 30% in females (21% in the form of EPA and 9% in the form of DHA). Interestingly, poultry (laying hens) appear to have a considerably greater potential for conversion of dietary LNA to DHA. For example, the inclusion of flax seed as a source of LNA in poultry rations (up to 10% of total feed weight) has been found to result in omega-3 eggs containing approximately 300 mg of LNA omega-3 along with approximately 80 mg of DHA omega-3. Thus, the inclusion of LNA in the ration of laying hens results in a substantial conversion to DHA and a considerable enrichment of the egg in DHA as well as LNA. With respect to publications from my laboratory at the University of Guelph, this information can be accessed from going to my personal webpage at the University of Guelph (