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Objective: To assess the association of having been breast fed with social class mobility between childhood and adulthood. Design: Historical cohort study with a 60-year follow-up from childhood into adulthood. Setting: 16 urban and rural centres in England and Scotland. Participants: 3182 original participants in the Boyd Orr Survey of Diet and Health in Pre-War Britain (1937–39) were sent follow-up questionnaires between 1997 and 1998. Analyses are based on 1414 (44%) responders with data on breast feeding measured in childhood and occupational social class in both childhood and adulthood. Main outcome: Odds of moving from a lower to a higher social class between childhood and adulthood in those who were ever breast fed versus those who were bottle fed. Results: The prevalence of breast feeding varied by survey district (range 45-86%) but not with household income (p=0.7), expenditure on food (p=0.3), number of siblings (p=0.7), birth order (p=0.5) or social class (p=0.4) in childhood. Participants who had been breast fed were 41% (95% CI 10% to 82%) more likely to move up a social class in adulthood (p=0.007) than bottle-fed infants. Longer breastfeeding duration was associated with greater odds of upward social mobility in fully adjusted models (p for trend=0.003). Additionally controlling for survey district, household income and food expenditure in childhood, childhood height, birth order or number of siblings did not attenuate these associations. In an analysis comparing social mobility among children within families with discordant breastfeeding histories, the association was somewhat attenuated (OR 1.16; 95% CI 0.74 to 1.8). Conclusions: Breast feeding was associated with upward social mobility. Confounding by other measured childhood predictors of social class in adulthood did not explain this effect, but we cannot exclude the possibility of residual or unmeasured confounding. [ABSTRACT FROM AUTHOR]

Associations between childhood BMI and adult cancer risk were investigated in a historical cohort study based on the Carnegie ("Boyd Orr") Survey of Diet and Health in Pre-War Britain (1937-9). In 14 centres in England and Scotland, children had their height and weight measured. We included 2,347 individuals aged between 2 and 14 years 9 months at the time of measurement, who were traced through the National Health Service Central Register. Relative cancer risk (registration or death) was estimated in relation to age- and sex-specific BMI SD scores. We studied associations with (i) all cancers, (ii) cancer groups stratified according to their relationship to smoking and (iii) certain site-specific cancers. In the 50 years of follow-up, 188 men and 192 women developed cancer. There was a 9% increase (95% CI -3 to 22%) in risk of cancer in adulthood per SD increase in BMI measured in childhood. There was no evidence of confounding by childhood or adulthood socioeconomic position, other anthropometric variables, childhood energy intake or birth order. There was a 30% increase (95% CI 10-54%) in risk of smoking-related cancers per SD increase in childhood BMI. There was no relationship between BMI and cancers not related to smoking. Associations for all cancers and non-smoking-related cancers tended to be stronger in children who were measured at an older (>8 years) rather than a younger (< or =8 years) age. We conclude that childhood BMI is related to increased risk of cancer in later life, particularly smoking-related cancers., (Copyright 2004 Wiley-Liss, Inc.)