Stable Carbon Isotope Signatures in Human Blood From 200 Individuals: A potential biochemical assay for the consumption of high fructose corn syrup
Rebecca A. Kraft Powerpoint Slides Here we present the first steps in the development of a biomarker for the consumption of high fructose corn syrup. Corn consumption is a powerful example of shifting dietary practices and degradation of health in first world countries. Within a global context, the gross increase in the consumption of corn and corn derivatives, most dramatically high fructose corn syrup, is a sustainability issue with far reaching health, economic, environmental and social ramifications. Objective chemical biomarkers are needed to improve clinical studies of dietary intake. Commonly ingested corn-derived foods and sugarcane-derived sucrose have stable carbon isotope signatures that are distinct from other foods. We propose these signatures could be used as biomarkers of intake. In order for such a bioassay to be of clinical value, a range of carbon stable isotope signatures must exist for human blood, and it must correlate with some measure of intake. Here we quantify the range of stable carbon isotope values (d13C) in blood (serum and blood clot) from 200 anonymous donors (100 males and 100 females). We observe similar isotopic signatures for males, females, blood clot and serum. Within the total sample (n=200) we observe a range of carbon isotope values (?15.6‰ to ?23.0‰) within the range of carbon isotopic values previously reported for common foods (approximately ?10‰ to ?30‰). This is consistent with the hypothesis that variable dietary intake of corn and cane- derived products could be reflected in blood, and is promising for the application of carbon stable isotopes as a new dietary biomarker of sweetener intake. It is our hope that the development of a biomarker will lead to a better understanding of the metabolism of dietary sugars, the establishment of safe levels of high fructose corn syrup for consumption, better blood sugar management for diabetics, and legislation designed to control and limit the incorporation of high fructose corn syrup into publicly funded diets such as school lunches. Rebecca Kraft is a second-year doctoral student working with Dr. Hope Jahren in the Health and Geosciences Program within the Department of Earth and Planetary Sciences at The Johns Hopkins University. She received her bachelor’s degree in geology from Bryn Mawr College in Bryn Mawr, Pennsylvania in 2003, and worked in environmental consulting for several years before pursuing her graduate degree. Her current research focuses on the application of stable isotope geochemistry to modern food webs to better understand the consumption and metabolism of dietary components and their relationship to diet-related disease. | 
