Dietary heterogeneity among western industrialized countries
reflected in the stable isotope ratios of human hair.
Luciano O. Valenzuela, Lesley A. Chesson, Gabriel J. Bowen, Thure E. Cerling, James R. Ehleringer
Abstract
Although the globalization of food production is often
assumed to result in a homogenization of consumption patterns with a
convergence towards a Western style diet, the resources used to make global
food products may still be locally produced (glocalization). Stable isotope
ratios of human hair can quantify the extent to which residents of
industrialized nations have converged on a standardized diet or whether there
is persistent heterogeneity and glocalization among countries as a result of
different dietary patterns and the use of local food products. Here we report
isotopic differences among carbon, nitrogen and sulfur isotope ratios of human
hair collected in thirteen Western European countries and in the USA. European
hair samples had significantly lower δ13C values (-22.7 to -18.3 ‰),
and significantly higher δ15N (7.8 to 10.3 ‰) and δ34S (4.8 to
8.3 ‰) values than samples from the USA (δ13C: -21.9 to -15.0 ‰, δ15N:
6.7 to 9.9 ‰, δ34S: -1.2 to 9.9 ‰). Within Europe, we detected
differences in hair δ13C and δ34S values among countries
and covariation of isotope ratios with latitude and longitude. This geographic
structuring of isotopic data suggests heterogeneity in the food resources used
by citizens of industrialized nations and supports the presence of different
dietary patterns within Western Europe despite globalization trends. Here we
showed the potential of stable isotope analysis as a population-wide tool for
dietary screening, particularly as a complement of dietary surveys, that can
provide additional information on assimilated macronutrients and independent
verification of data obtained by those self-reporting instruments.
Key words: Hair protein, stable isotopes, Western Europe,
dietary heterogeneity, glocalization, globalization.
doi:10.1371/journal.pone.0034234
