The effects of dietary supplementation on growth and adult mortality: a re-analysis and follow-up of a pre-war study.
The aim of this study was to re-analyse a diet supplementation study conducted in the 1930s and investigate the effects of food supplementation on children's growth and later adult mortality. A non-randomised controlled trial was carried out in eight of the sixteen centres participating in the Carnegie Survey of Diet and Health in pre-war Britain (1937-39). Food supplements were given for 12 months either at school or as food parcels sent to the family home. 545 children aged 2-14 received food supplements and 494 children of a similar age acted as their controls. The children came from 465 families. The increase in childhood height and its components-leg length and trunk length-over 12 months follow-up were measured. Mortality from all causes over 60 years follow-up to 1998 was also assessed. There were important differences between fed and control children at baseline. Supplemented children came from larger families with poorer diets and most were examined, on average, 12 days later than control children. After adjustment for baseline imbalances those receiving supplements increased in height by 3.7 mm (95% CI 1.9-5.5) more than the controls. After adjustment, most of the difference in growth appeared to arise as a result of increases in leg length. After adjustment for confounding factors measured in childhood, no significant effect of childhood food supplements on adult mortality was seen. The age-adjusted hazard ratio for all cause mortality was higher in the supplemented compared to control subjects: 1.13 95% CI (0.77-1.64). We found that provision of childhood food supplements led to increased growth amongst supplemented children. The increases in height in this study were mainly as a result of increases in leg length and are similar to those found in a more recent randomised trial in South Wales. Whilst other analyses suggest that childhood height is important in predicting adult mortality patterns, we found no significant effect of childhood food supplements on adult mortality patterns in this study, although the study lacked statistical power to detect small but, nevertheless, important differences in mortality. Larger randomised trials with long term follow-up would be required to investigate the impact of childhood food supplementation on adult health.
Gunnell
D
D
Department of Social Medicine, University of Bristol, Bristol, UK.
Smith
G D
GD
Ness
A R
AR
Frankel
S
S
D000293:Adolescent; D000328:Adult; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D018849:Controlled Clinical Trials as Topic; D019587:Dietary Supplements; D005260:Female; D005500:Follow-Up Studies; D005502:Food; D006801:Humans; D008297:Male; D009026:Mortality; D015337:Multicenter Studies as Topic