JAAS News

The influence of menstrual blood loss and age on the isotopic composition of Fe in human whole blood

Elements with multiple isotopes have varied isotopic compositions in nature as a result of isotope fractionation. Biomedical applications relying on isotopic analysis have become more popular. Cu, Fe and Zn isotopic analysis in blood has shown potential as a diagnostic tool for a number of diseases. Furthermore, the natural variations of these elements on healthy individuals can provide useful information.

Frank Vanhaecke and colleagues from Ghent University and Ghent University Hospital compared the isotopic values of Cu, Fe and Zn between men, menstruating women and two groups of non-menstruating women, women in their menopause and women with an intra-uterine device (IUD) used for contraception. The results indicated that Cu and Fe isotopic composition of whole blood is affected by menstruation, since the results for both groups of non-menstruating women were significantly different from those of menstruating women and much like those for men. On the other hand, Zn isotopic composition seems to be affected by age, since there was a significant difference between menopausal women and women using the IUD. The authors suggest this difference can be explained by the different hormone levels.

The method used for the isotopic measurements was multi-collector inductively coupled plasma- mass spectrometry (MC-ICP-MS). The method was chosen for its significantly higher sample throughput capacity and also the higher ionisation efficiency for the transition metals investigated.

To read the full article, please access the link below. This paper will be free to read until 1 of May 2014.

Added sugars have been associated with negative effects on health, most important of which are cardiovascular diseases, the leading cause of mortality in the US. They supply around 16% of the total calories in the American diet, up from less than 11% in the late 1970s.  Under-reporting and subjectivity in self-assessment studies of sugar intake have so far prevented conclusive evidence for the relationship between added sugar intake and negative health effects.

A. Hope Jahren and colleagues from the University of Hawaii and the Virginia Tech assessed the potential of δ¹³C measurements of different biological substrates  for the evaluation of added sugar intake. 78% of added sugars come from C4 plants which differ from other plants on their  δ¹³C values by as much as 20‰, while the uncertainty in measuring these values is usually less than 0.1‰.

Previous studies suggest that the δ¹³C value of blood is a promising biomarker for added sugars and sugar-sweetened beverages in medium-term time-frame. Fingerstick-based blood sampling is especially convenient because it is non-invasive and requires minimal equipment and training, while the samples are easy to transport and store. Specific compound approaches are also discussed, with the hemoglobin A1c being a potential biomarker not susceptible to short-term changes in diet.

Although continued research is needed, δ¹³C is shown to be a promising potential biomarker of added sugar intake.

To read the full article, please access the link below. This paper will be free to read until 11 of April 2014.