Schooling et al. BMC Public Health 2011, 11:345 http://www.biomedcentral.com/1471-2458/11/345 R E S E A R C H A R T I C L E Open Access Childhood meat eating and inflammatory markers: The Guangzhou Biobank Cohort Study CM Schooling1,4, CQ Jiang2, TH Lam1*, WS Zhang2, KK Cheng3 and GM Leung1 Abstract Background: We hypothesized that socio-economic development could, via nutritionally driven levels of pubertal sex-steroids, promote a pro-inflammatory state among men but not women in developing countries. We tested this hypothesis, using recalled childhood meat eating as a proxy for childhood nutrition, in southern China. Methods: We used multivariable linear regression in the Guangzhou Biobank Cohort Study phase 3 (2006-8) to examine the adjusted associations of recalled childhood meat eating, <1/week (n = 5,023), about once per week (n = 3,592) and almost daily (n = 1,252), with white blood cell count and its differentials among older (≥50 years) men (n = 2,498) and women (n = 7,369). Results: Adjusted for age, childhood socio-economic position, education and smoking, childhood meat eating had sex-specific associations with white blood cell count and lymphocyte count, but not granulocyte count. Men with childhood meat eating almost daily compared to <1/week had higher white blood cell count (0.33 109/L, 95% confidence interval (CI) 0.10 to 0.56) and higher lymphocyte count (0.16 109/L, 95% CI 0.07 to 0.25). Adjustment for obesity slightly attenuated these associations. Conclusion: If confirmed, this hypothesis implies that economic development and the associated improvements in nutrition at puberty may be less beneficial among men than women; consistent with the widening sex differentials in life expectancy with economic development. Keywords: Cardiovascular disease, inflammation, sex, China, developing country, white blood cell count, childhood nutrition Background In long term industrialized western populations poor childhood conditions are associated with cardiovascular disease [1], although the underlying biological pathway is unclear. Cardiovascular disease may have an inflam- matory component [2,3]. Poor childhood conditions are also usually associated with a pro-inflammatory state [4-9]. It is increasingly clear that the social patterning of cardiovascular disease or its risk factors, both traditional and non-traditional, is not universal but epidemiologic stage specific [9-14]. There is often a more marked and longer lasting reversal of the usual social patterning among men than women [9-11] for reasons which have * Correspondence: hrmrlth@hkucc.hku.hk 1School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China Full list of author information is available at the end of the article tended to be interpreted mainly in terms of contem- poraneous risk factors that differ by sex [11]. A factor that countered the generally protective effect of social advantage among men at the early stages of eco- nomic development would explain the observed patterns. Inter-generationally and nutritionally driven increases in the amount, tempo and intensity of pubertal development with macro-economic improvement provide a potential explanation [10,15], because pubertal sex-steroids may have long-term sex-specific effects on fat patterning [16], some lipids [17,18] and immune responsiveness [19-21], which are detrimental among men but sometimes protec- tive among women [16-22]. There is increasing evidence from populations with a recent history of economic devel- opment, that growing up in more affluent conditions is positively associated among men, but not women, with central obesity [10], ischemic heart disease [23-26] and inflammation [9]. However, the positive association with © 2011 Schooling et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.