Homogeneous diet of contemporary Japanese inferred from stable isotope ratios of hair.
The globalization of food production and distribution has homogenized human dietary patterns irrespective of geography, but it is uncertain how far this homogenization has progressed. This study investigated the carbon and nitrogen isotope ratios in the scalp hair of 1305 contemporary Japanese and found values of -19.4 ± 0.6‰ and 9.4 ± 0.6‰ (mean ± SD), respectively. Within Japan, the inter-regional differences for both isotope ratios was less than 1‰, which indicates low dietary heterogeneity among prefectural divisions. The carbon and nitrogen isotope ratios of the hair showed a significant correlation with the results of questionnaires on self-reported dietary habits. The carbon isotope ratios from Japan were lower than those in samples from the USA but higher than those in samples from Europe. These differences stem from the varying dietary proportions of food products originally derived from C3 and C4 plants. The dietary variation of Japan is as small as those of Europe and USA and smaller than those of some Asian countries. These results indicate that dietary homogeneity has progressed in Japan, which may indicate the influence from the spread of the Western-style diet and food globalization, although dietary heterogeneity among countries is still preserved.
Research Institute for Humanity and Nature, Kyoto 603-8047, Japan.|Museum of Natural and Environmental History, Shizuoka, Shizuoka 422-8017, Japan.
Soichiro
S
Kusaka
Research Institute for Humanity and Nature, Kyoto 603-8047, Japan.|Hiroshima University Museum, Hiroshima University, Hiroshima 739-8524, Japan.
Eriko
E
Ishimaru
Research Institute for Humanity and Nature, Kyoto 603-8047, Japan.|Research Core for Interdisciplinary Sciences, Okayama University, Okayama 700-8530, Japan.
Fujio
F
Hyodo
School of Medicine, Kitazato University, Kanagawa 252-0374, Japan.
Takashi
T
Gakuhari
The University Museum, The University of Tokyo, Tokyo 113-0033, Japan.
Minoru
M
Yoneda
Research Institute for Humanity and Nature, Kyoto 603-8047, Japan.|Primate Research Institute, Kyoto University, Aichi 484-8506, Japan.
Takakazu
T
Yumoto
Research Institute for Humanity and Nature, Kyoto 603-8047, Japan.|Center for Ecological Research, Kyoto University, Otsu 520-2113, Japan.
Ichiro
I
Tayasu
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D002247:Carbon Isotopes / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D004032:Diet; D005247:Feeding Behavior; D005260:Female; D006197:Hair / Q000737:chemistry*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D008297:Male; D008875:Middle Aged; D009587:Nitrogen Isotopes / Q000032:analysis*; D055815:Young Adult
D002247:Carbon Isotopes; D009587:Nitrogen Isotopes