2026/04/15 by Jun Yoshinaga, Ryuta Oyama · 1 voice
Environmental Science · #Isotope Analysis in Ecology #Marine Bivalve and Aquaculture Studies #Marine and fisheries research
paper · doi:10.1002/rcm.70082
openalex publication_date 2026/04/15 · openalex created_date 2026/04/16 · openalex updated_date 2026/07/31
ABSTRACT Rationale Carbon and nitrogen stable isotope ratios (δ 13 C and δ 15 N) of whole diet have rarely been measured to date though the isotope ratios in human sample have been extensively used for diet and nutritional researches. In order to fully validate the isotope dietary analysis, association between quantitative information on diet composition and isotope ratios is required to be compared. Methods Duplicate diet samples collected from 30 adult Japanese participants of a human biomonitoring survey in 2012 and 2014 were measured for δ 13 C and δ 15 N by element analyzer‐isotope ratio mass spectrometry. The correlation between δ values and the abundances of 12 food categories included in the diet samples, of which weight was separately measured at the time of diet sampling, was examined. Results Mean ± standard deviation of δ 13 C and δ 15 N values of the 30 duplicate diets were −24.4 ± 0.7 and 4.64‰ ± 0.82‰, respectively. Correlation between δ 15 N value and % abundance of “fish and shellfish” ([weight of “fish and shellfish”] / [total weight of duplicate diet] (%)) in the diet was highly significant ( r = 0.752, p < 0.001), indicating that seafood abundance is a major determinant of diet δ 15 N value. Abundance of pulse also had a negative association with δ 15 N value due to low δ 15 N value of pulse. The δ 13 C value of duplicate diet was significantly correlated with % abundance of “rice and rice products” ( r = −0.603, p < 0.001) and of “meat and egg” ( r = 0.489, p < 0.01). The reason of the latter was ascribed to less negative δ 13 C value of meat and egg from livestock raised on corn‐based feed, but the reason(s) of the former was not known. Conclusion The highly significant positive correlation between the abundance of seafood and δ 15 N supports the utility of δ 15 N of biological samples for isotopic diet reconstruction/nutritional research.