A growth study of Japanese descendants from São Paulo, Brazil

See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/250005141 A growth study of Japanese descendants from São Paulo, Brazil Article in Anthropological Science · August 2005 DOI: 10.1537/ase.040702 CITATION READS 1 25 2 authors: Lucio Vinicius Marta Mirazon Lahr 40 PUBLICATIONS 484 CITATIONS 125 PUBLICATIONS 5,086 CITATIONS University College London SEE PROFILE University of Cambridge SEE PROFILE Some of the authors of this publication are also working on these related projects: IN-AFRICA View project All content following this page was uploaded by Marta Mirazon Lahr on 16 November 2014. The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. ANTHROPOLOGICAL SCIENCE Vol. 113, 163–167, 2005 A growth study of Japanese descendants from São Paulo, Brazil LUCIO VINICIUS1*, MARTA M. LAHR1 1 Leverhulme Centre for Human Evolutionary Studies, Department of Biological Anthropology, University of Cambridge, Downing Street, Cambridge CB2 3DZ, UK Received 3 July 2004; accepted 2 October 2004 Abstract We describe the growth pattern of a sample of Japanese descendants born in São Paulo, Brazil. Cross-sectional data from 1297 subjects were obtained in eight middle- and upper middle-class schools. Weight and height of children of Japanese ancestry were compared both to populations of similar socio-economic status, namely the well-off European descendants born in São Paulo and the United States, and to populations of similar genetic background from Japan and urban China. Adult size is smaller in Brazilians of Japanese ancestry than in the samples of European ancestry. We show that the Brazilian-born Japanese descendants do not display any growth deficits during the preadolescent period but fall short of the US growth standard afterwards, suggesting that the adolescent growth spurt is responsible for their smaller body size at adulthood. The observed height deficit is more pronounced than the weight deficit in both boys and girls. On the other hand, when comparisons include only populations of Asian origin, the Japanese descendants from São Paulo are shown to be similar in height and weight to the better-off children living in Japan, and significantly larger than the urban Chinese children of relatively lower socio-economic status. Key words: growth, Japanese descendants, anthropometric references, Brazil immigration from Europe, mainly driven by the expansion of coffee plantations during the second half of the 19th century. Between 1873 and 1903, approximately 2,000,000 Europeans migrated to Brazil, especially from Italy (almost 60% of the total), Portugal, Spain, and Germany (Levy, 1974). During the first half of the 20th century, Japanese migrants (mainly peasants with very little means) added to the huge foreign contingent totaling 250,000 by 1950 and giving rise to the one of the largest (if not the largest) Japanese communities outside Japan (Yamashita, 2001). As the process of industrialization and urbanization intensified in the first decades of the 20th century, many Japanese immigrants and descendants moved from rural environments to the city of São Paulo. The Japanese community of São Paulo had remained relatively closed but today it is very much integrated with the rest of the population. Japanese descendants in São Paulo make up an important proportion of the wealthier private school sector, as well as of the city’s university graduates. Therefore, Japanese descendants differ in terms of geographic origin from European descendants of similar socio-economic status growing up in the same city neighborhoods and attending the same wealthy schools, and also contrast with Brazilians in general due to their successful socio-economic history. This study describes growth in weight and height of Japanese descendants born in São Paulo, and compares them to children and adolescents of European background from the same city, school, and socio-economic status. Growth of the Japanese sample is also interpreted relative to better-off populations from the USA and to other anthropometric studies undertaken in Japan and China. Introduction Since the rebirth of the debate on human origins in the late 1980s (Stringer, 1990; Lahr, 1996), evolutionary anthropology has again drawn attention to population dynamics and geographical differentiation. The sustained effort of paleoanthropology revealed that metric variation between human groups is partially associated with the process of dispersal of modern humans from an ancestral African source and subsequent diversification driven by different adaptive and demographic histories (Cavalli-Sforza et al., 1994; Fix, 1999). On the other hand, differences in human growth also result from environmental and socio-economic factors, such as nutrition, health, and social status (Eveleth, 1986). The phenomenon of a secular trend in body size (van Wierigen, 1986), or increase in weight and height of a population in the timescale of a few generations or within a single generation, observed in North America, Europe, Japan, and developing countries, results from a general improvement of living standards observed in those populations. This context grounds the present report on the growth of children and adolescents of Japanese descent from the city of São Paulo, Brazil. The biometrical identity of this population derives from both genetic and environmental factors, since the demographic and economic history of the Japanese descendants distinguish them from the other inhabitants of São Paulo. The city was characterized in the past by intense * Corresponding author. e-mail: lvc22@hermes.cam.ac.uk phone: +44-1223-335-461; fax: +44-1223-335-460 Published online 10 December 2004 in J-STAGE (www.jstage.jst.go.jp) DOI: 10.1537/ase.040702 © 2004 The Anthropological Society of Nippon 163 164 L. VINICIUS AND M.M. LAHR ANTHROPOLOGICAL SCIENCE Subjects and Methods The study is based on a cross-sectional sample of 1297 children and adolescents aged 7–17 years (647 boys and 650 girls) of Japanese ancestry, from eight private schools in the city of São Paulo in 1999. These schools are attended by middle- and upper middle-class children, which are therefore wealthier on average than the total Japanese population either in São Paulo or in Brazil. We included in the sample only children whose four grandparents were born in Japan (identified through the assessment of school records), which corresponded to approximately 10% of the student population of these schools. Ages were assessed directly from school registers. In tables and graphs, age cohorts are represented in the ‘±’ scale (e.g. cohort 7 designates children aged 6.5–7.49 years). A correction was made whenever we used comparative data based on the alternative ‘+’ scale. For example, in the growth survey carried out by the Japanese government (MEXT, 2004), cohort 7 represents children aged 7–7.99 years, and this was converted to age 7.5 in our ‘±’ scale. Since our data were collected in 1999, we used Japanese data for the year 2000 in the comparisons, instead of the more recent 2003 dataset (MEXT, 2004). In some cases, it was not possible to measure both weight and height of the same subject, so that the total number of weight measurements is 647 for boys and 650 for girls, and the total number of height measurements is 646 for boys and 648 for girls. Data collection was mostly performed by one of us (L.V.) and complemented with data collected by graduate schoolteachers. Inter-observer error was not significant (data not shown). Anthropometrical measurements were taken during physical exercise classes, so that weights and heights were taken of subjects barefoot with light clothing. Stature was recorded to the nearest centimeter by the use of a stadiometer, and no upward pressure was applied beneath the mastoid process. Weight was recorded to the nearest 0.1 kg, except where a digital scale displaying exact values in intervals of 0.05 kg was used. Differences between values obtained from each scale are not statistically significant. Comparative data from children and adolescents of European origin (3984 boys and 3894 girls) were collected at the same schools and are described elsewhere (Castilho and Lahr, 2001). The Japanese sample was also compared to the 2000 CDC (Centers for Disease Control and Prevention, Department of Health and Human Services) growth reference from the USA (Kuczmarski et al., 2000). We used the software ‘EPI Info’ (CDC) to convert weight for age and height for age of our samples into CDC centiles. We assessed differences in weight and height between Japanese descendants born in São Paulo and populations from Japan (MEXT, 2004) and urban China (Lin et al., 1992) by means of independent samples t-tests. Results Comparison between children of Japanese and European ancestry born in São Paulo reveals lower mean values of weight and height throughout the growth period in the Japanese subjects (Figure 1, Figure 2, Table 1), but those differences are statistically significant only after the beginning of Figure 1. Weight vs. age of boys (circles) and girls (squares) of Japanese (black symbols) and European (white symbols) ancestry from São Paulo, Brazil. Figure 2. Height vs. age of boys (circles) and girls (squares) of Japanese (black symbols) and European (white symbols) ancestry from São Paulo, Brazil. adolescence. Boys of European ancestry are significantly taller only from age 15 and heavier only from age 17 (independent samples t-test, P < 0.001), while European girls are significantly taller and heavier (P < 0.001), respectively, from the ages 14 and 15 on. At 17 years, the mean weight and height of Japanese boys are 64 kg and 170.4 cm, respectively, while European boys show mean values of 68.8 kg and 176.2 cm (Castilho and Lahr, 2001). For Japanese girls, the average weight and height at age 17 are 52 kg and 160.4 cm, while in European girls the mean values are 56.1 kg and 164 cm. In spite of the cross-sectional nature of our data, the results point to the adolescent growth spurt as responsible for the Japanese shortfall, in both sexes, in adult body size relative to the population of European ancestry. Japanese descendants were also compared to a wealthy US sample of European ancestry, by converting their mean values into centiles of the reference CDC distribution (Figure 3, Figure 4). The mean weight of Japanese boys and girls is significantly above the US reference during the pre-adolescent period. At 8 years, for example, the weight and Vol. 113, 2005 GROWTH OF JAPANESE DESCENDANTS IN BRAZIL 165 Table 1. Mean weight (kg) and height (cm) of boys and girls of Japanese descent born in São Paulo, Brazil Age 7± 8± 9± 10 ± 11 ± 12 ± 13 ± 14 ± 15 ± 16 ± 17 ± Boys Girls Weight (SD, n) Height (SD, n) Weight (SD, n) Height (SD, n) 24.94 (4.8, 18) 28.36 (6.0, 28) 33.74 (8.2, 28) 34.43 (5.0, 28) 40.91 (11.8, 44) 43.61 (11.0, 36) 50.99 (11.8, 50) 56.39 (14.3, 61) 60.74 (12.5, 135) 64.54 (12.3, 110) 64.05 (13.0, 109) 120.58 (5.78, 18) 128.32 (5.2, 28) 134.21 (5.6, 28) 137.15 (4.5, 28) 144.86 (8.1, 44) 148.93 (6.1, 36) 158.06 (7.7, 50) 163.31 (6.5, 61) 168.07 (6.8, 135) 169.67 (6.7, 110) 170.42 (5.6, 108) 23.59 (3.4, 16) 26.59 (4.4, 15) 32.02 (7.9, 26) 33.21 (7.3, 17) 40.1 (7.9, 39) 43.31 (8.8, 34) 48.97 (10.7, 41) 49.96 (8.0, 72) 51.1 (9.0, 150) 52.64 (7.0, 155) 52.01 (6.6, 85) 122.38 (5.2, 16) 128.13 (3.5, 15) 132.35 (7.2, 26) 137 (6.6, 17) 146.84 (6.9, 39) 151.51 (7.0, 34) 156.6 (5.5, 41) 158.39 (5.0, 72) 159.38 (6.1, 150) 159.84 (5.6, 155) 160.4 (5.2, 85) Standard deviation and sample size are given as (SD, n). Figure 3. Weight (white symbols) and height (black symbols) of boys (circles) and girls (squares) of Japanese ancestry from São Paulo, expressed as centiles of the CDC growth reference. height of Japanese boys are above the 81st and 69th centiles, respectively. The height of boys and girls also oscillates around the 50th centile, indicating no shortfall in growth. However, moving towards the oldest cohorts, a decrease of the Japanese values for both weight and height in both sexes is evident. Differentiation from the US reference is faster in height, whose average in girls falls below the 50th centile at age 13, and in boys at age 14. The weight of girls is below the 50th centile at age 15. By 17 years, height in both sexes is well below the reference values, corresponding respectively to the 25th (boys) and 35th (girls) centiles, while female weight corresponds to the 33rd centile. Only weight in boys remains close to the US average (48th centile), despite a similar fall in relative values during adolescence. The results confirm the role of the adolescent growth spurt as responsible for the shortfall in growth of Japanese descendants born in São Paulo. Our sample population is smaller in size than the US sample despite similar socio-economic status. Comparisons between the Brazilian Japanese sample and two populations living in Japan and China were also carried out. While Japanese descendants from Brazil seem to grow slightly faster than children born and living in Japan (MEXT, 2004), catch up growth in the latter implies that at age 17 only female height is still significantly larger (P < 0.01, independent samples t-test) in the children from São Paulo. On the other hand, comparison with Chinese children and adolescents living in urban areas of China (Lin et al., 1992) revealed significant differences. With the exception of female height, Japanese descendants born in São Paulo exhibited significantly larger sizes compared to Chinese boys and girls, not only throughout the growth period but also as young adults (age 17). The differences emerge despite the fact that the Chinese sample is exclusively urban. If children living in rural China (also sampled by Lin et al., 1992) had been included in the comparisons, their growth deficit relative to the Japanese descendants born in São Paulo would be more evident. Unfortunately, more recent data for the Chinese are not available. Discussion and Conclusions We identified significant shortfalls in the growth of welloff Japanese descendants from São Paulo, Brazil, both in relation to a population of European descendants living in the same city and to an US sample of equally high economic status. The Brazilian Japanese sample begins to display growth deficits after the onset of adolescence, suggesting that a different timing and intensity of the growth spurt may be responsible for their smaller adult weight and height, but the cross-sectional nature of our data does not allow a deeper assessment of this question, which would require longitudinal data in order to be fully addressed. We showed previously that European descendants from the same schools do not exhibit any growth deficits in relation to the WHO/ NCHS reference (Castilho and Lahr, 2001). A different picture emerges when the comparisons comprise only populations of Asian origin. Adult Japanese subjects from São Paulo and Japan show comparable weight and height, with the single exception of female height. The Japanese national survey in the year 2000 (MEXT, 2004) portrayed the growth of an Asian population of high socio- 166 L. VINICIUS AND M.M. LAHR ANTHROPOLOGICAL SCIENCE Figure 4. Weight (A and C) and height (B and D) of boys and girls of Asian populations from São Paulo (white circles), Japan (black circles), and China (white squares). economic status, and therefore both the common genetic background and equivalent social status explain the similarity in growth patterns with the Brazilian sample. On the other hand, the Chinese anthropometric study used in our analyses was undertaken in the 1980s and thus predated most of the recent economic boom in China, and therefore represents a population of lower socio-economic status than that of Japanese descendants from São Paulo. It seems evident that, in growth studies of children of Asian background, the national Japanese data (MEXT, 2004) should be used as the standard for healthy growth instead of the 2000 CDC reference. Acknowledgments We thank the schools Rainha da Paz, Etapa, Humboldt, Augusto Laranja, Pueri Domus, Rio Branco, Santa Cruz and Sion. 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