C-13 natural abundance in the British diet: implications for C-13 breath tests

Surprisingly little information is available on the natural abundance of th e minor isotope of carbon, C-13, in common foodstuffs in the British diet. This study therefore aimed to examine the C-13 natural abundance of foodstu ffs from a small cross-section of the British diet. The isotopic abundance, delta per mil, was calculated by measurement of the isotope ratio C-13:C-1 2 by isotope ratio mass spectrometry. Results from this study were also com pared with results from a North American study to highlight the difference in isotopic abundance between Northern European foodstuffs and North Americ an foodstuffs, Such data should prove useful to those planning tracer studi es using the stable isotope C-13 where enrichment is measured against a lar ge and variable natural abundance in the body. Minimisation of this basal v ariation, for example in breath CO2, can be achieved by controlling dietary intake of foods naturally abundant in 13C. Copyright (C) 2000 John Wiley & Sons, Ltd.