Purpose: Dietary biomarkers can potentially overcome the limitations of self-reported dietary data. While in ecology and archaeology, stable isotope ratios of carbon and nitrogen are widely used as biomarkers, this is not the case in nutrition research. Since the abundance of the 13C and the 15N isotope differ in food sources from plant and animal origin, stable isotope ratios of carbon and nitrogen (δ13C and δ15N) may differ in human biological material. Here, we investigated the stable isotope ratios of nitrogen and carbon in serum and urine from vegans and omnivores.
Method: Measurement of δ15N and δ13C in serum and 24 h urine was performed by Elemental Analyzer-Isotope Ratio Mass Spectrometer in the cross-sectional study "Risks and Benefits of a Vegan Diet". The study included 36 vegans and 36 omnivores with a median age of 37.5 years (matched for age and sex), who adhered to their diet for at least 1 year.
Results: Both δ15N and δ13C were significantly lower in both the serum and 24 h urine of vegans compared to omnivores. δ15N either in serum or urine had 100% specificity and sensitivity to discriminate between vegans and omnivores. Specificity of δ13C was also > 90%, while sensitivity was 93% in serum and 77% in urine.
Conclusion: δ15N both in serum and urine was able to accurately identify vegans and thus appears to be a promising marker for dietary habits.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9899720 | PMC |
http://dx.doi.org/10.1007/s00394-022-02992-y | DOI Listing |
Rapid Commun Mass Spectrom
April 2025
Department of Earth and Environmental Sciences, Indiana University Indianapolis, Indianapolis, Indiana, USA.
Rationale: Fog, dew, and rain are crucial for sustaining ecosystem functions, especially in water-limited regions. However, they are subject to isotopic changes during storage due to their usual small sample volumes and inherent sensitivity to atmospheric particulates. Understanding long-term storage effects on these water samples is essential for ensuring isotopic integrity.
View Article and Find Full Text PDFPlant Cell Environ
January 2025
The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
Nitrate reduction requires reducing equivalents produced by the photosynthetic electron transport chain. Therefore, it has been suggested that nitrate assimilation provides a sink for electrons under high light conditions. We tested this hypothesis by monitoring photosynthetic efficiency and the chloroplastic glutathione redox potential (chl-E) of plant lines with mutated glutamine synthetase 2 (GS2) and ferredoxin-dependent glutamate synthase 1 (GOGAT1).
View Article and Find Full Text PDFCell Mol Biol Lett
January 2025
Enzymology and Metabolism Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367, Belvaux, Luxembourg.
Background: Metabolism is error prone. For instance, the reduced forms of the central metabolic cofactors nicotinamide adenine dinucleotide (NADH) and nicotinamide adenine dinucleotide phosphate (NADPH), can be converted into redox-inactive products, NADHX and NADPHX, through enzymatically catalyzed or spontaneous hydration. The metabolite repair enzymes NAXD and NAXE convert these damaged compounds back to the functional NAD(P)H cofactors.
View Article and Find Full Text PDFSci Rep
January 2025
Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan.
Phytotoxic air pollutants such as atmospheric nitrogen dioxide (NO) are among the major stresses affecting tree photosynthesis in urban areas. We clarified the relationship between NO concentrations and photosynthetic function for three major urban trees, Prunus × yedoensis, Rhododendron pulchrum, and Ginkgo biloba, planted in Kyoto and surrounding cities, combining our published data and new data collected from 2020 to 2023. High NO increased long-term water use efficiency for all species.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
March 2025
School of Earth, Environment & Society, McMaster University, Hamilton, Ontario, Canada.
Rationale: Carbonate minerals are one of the most popular samples for an automated sample preparation system for CF-IRMS, such as GasBench II and iso FLOW, but no standardized analytical protocols exist. This study gives guidelines on optimal analytic conditions for carbon and oxygen isotope analysis of Ca-Mg carbonates when using the carbonate-phosphoric acid reaction method.
Methods: Calcite (CaCO-McMaster Carrara), dolomite (CaMg(CO)-MRSI Dolomite), and magnesite (MgCO-ROM Brazil Magnesite) with two grain size fractions (< 74 and 149-250 μm) were reacted with 103% (specific gravity of 1.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!