Scientists propose new marker for blood omega-3 levels

US scientists have reported that the stable nitrogen isotope 15N may be a suitable biomarker to analyse blood levels of EPA and DHA intake in clinical and epidemiologic studies.

Scientists from the University of Alaska Fairbanks and the Fred Hutchinson Cancer Research Center in Seattle report that the ratio between 15N and 14N is elevated in fish, and therefore levels of 15N could be a suitable measure for EPA and DHA intake.

Writing in the American Journal of Clinical Nutrition, they report that analysis of the 15N levels in red blood cells of Yup’ik Eskimos were “strongly correlated with red blood cell EPA and DHA”, and “also correlated with dietary EPA and DHA intake”.

“The results strongly support the validity of RBC {delta}15N as a biomarker of EPA and DHA intake. Because the analysis of RBC {delta}15N is rapid and inexpensive, this method could facilitate wide-scale assessment of EPA and DHA intake in clinical and epidemiologic studies,” they concluded.

Source: American Journal of Clinical NutritionMarch 2009, Volume 89, Number 3, Pages 913-919, doi:10.3945/ajcn.2008.27054 “Red blood cell {delta}15N: a novel biomarker of dietary eicosapentaenoic acid and docosahexaenoic acid intake”Authors: D.M. O'Brien et al.