More infant breastfeeding is linked to higher intelligence, a longer period in education and greater earnings 30 years later, a new study finds.
Dr Bernardo Lessa Horta, who led the study, said:
“The effect of breastfeeding on brain development and child intelligence is well established, but whether these effects persist into adulthood is less clear.
Our study provides the first evidence that prolonged breastfeeding not only increases intelligence until at least the age of 30 years but also has an impact both at an individual and societal level by improving educational attainment and earning ability.
What is unique about this study is the fact that, in the population we studied, breastfeeding was not more common among highly educated, high-income women, but was evenly distributed by social class.
Previous studies from developed countries have been criticized for failing to disentangle the effect of breastfeeding from that of socioeconomic advantage, but our work addresses this issue for the first time.”
The study of breastfeeding benefits followed almost 6,000 infants in Brazil from 1982.
They were placed into one of five groups depending on how often they were breastfed.
At the same time the researchers controlled for other factors that might affect IQ, like family income, maternal smoking and genetics.
The researchers found that infants who were breastfed for a year scored, on average, 4 IQ points higher than those who were breastfed for less than a month.
Breastfed infants also went on to spend one more year in education, on average, and earn one-third of the average national income more.
Dr Horta said:
“The likely mechanism underlying the beneficial effects of breast milk on intelligence is the presence of long-chain saturated fatty acids (DHAs) found in breast milk, which are essential for brain development.
Our finding that predominant breastfeeding is positively related to IQ in adulthood also suggests that the amount of milk consumed plays a role.”
The study is published in the journal The Lancet Global Health (Victora et al., 2015)
About the author
Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology.
He has been writing about scientific research on PsyBlog since 2004. He is also the author of the book “Making Habits, Breaking Habits” (Da Capo, 2003) and several ebooks:
- Accept Yourself: How to feel a profound sense of warmth and self-compassion
- The Anxiety Plan: 42 Strategies For Worry, Phobias, OCD and Panic
- Spark: 17 Steps That Will Boost Your Motivation For Anything
- Activate: How To Find Joy Again By Changing What You Do
Breastfeeding image from Shutterstock