Breastfeeding has short-term and longterm beneficial effects on child.It is already known that breastfeeding increase the average IQ by 3.5 points at childhood and adolescence. RCT evidence also support this meta analytic measure from observational studies. In developed countries, longer duration of breastfeeding is associated with higher socio-economic status and thus this might confound the observed associations.The real life effect of small differences in IQ is not known.It is not known whether breastfeeding will influence the income in adults.
This study reported by Cesar G Victora et al from Brasil offers a rare opportunity to unravel such long-term effects. They studied the associations between infant feeding and IQ, educational attainment, and income in participants aged 30 years in a large population-based birth cohort, in Brazil ( a setting where no strong social patterning of breastfeeding exists). The neonatal cohort was recruited in 1982 with 5914 participants.IQ (Wechsler Adult Intelligence Scale) was assessed at mean age of 30. A range of confounders were measured (income, maternal education, smoking,maternal age,gestational age, birth weight etc). Genomic ancestry analysis was also done.
At the age of 30 years, the mean IQ of offspring was 98·0 (SD 12·6) points and the average number of years of education was 11·4. Distribution of monthly income had a median of R$1000 and a mean of R$1501.
Durations (total/predominant) breastfeeding were positively associated with IQ, educational attainment, and income.The adjusted differences between the extreme groups ( on breast feeding) were 3·76 (95% CI 2·20–5·33) IQ points, 0·91 (0·42–1·40) years of education, and R$341 (93·8–588·3) in adult income. Dose-response associations with breastfeeding duration for IQ and educational attainment and income were clear. Income difference was on average of 341·0 Brazilian reals compared to those who were breastfed for less than 1 month.
This is the first study to show a positive association of breastfeeding with adult earnings. The analysis also show that this effect was largely mediated through intelligence levels.
Comments: Breastfeeding’s effect on IQ , education and income need to be brought in to antenatal discussions/public health campaign . The positive effects shown here are very much likely to contribute to better mental health as well.
Summary of the article:
Victora CG, Horta BL, Loret de Mola C, Quevedo L, Pinheiro RT, Gigante DP, Gonçalves H, Barros FC.
Lancet Glob Health. 2015 Apr;3(4):e199-205.