Mothers have long been encouraged to breastfeed their babies to support their health and emotional well being. Now a new study from Brazil has demonstrated that breastfed infants grow up to be more intelligent, spend a longer time in education, and earn more money than their bottlefed counterparts. The study has been ongoing for the past three decades, and it has followed 6,000 babies of all backgrounds; the purpose of the study has been to understand the long-term effects of breastfeeding.
Dr. Bernard Lessa Horta from the Federal University of Pelotas in Brazil says it is already known that breastfeeding can increase a child’s IQ by a small amount. In this study, researchers wanted to learn whether or not this translated into greater intelligence and better prospects in adulthood. The researchers approached participants in the long-term study, now 30-year-old adults, and nearly 3,500 of them were willing to be interviewed and take IQ tests.
Says Dr. Horta:
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.
The Brazilian study is important for several reasons. First, of course, is the length and breadth of the research. Additionally, it is free of one drawback that affects many studies of breastfeeding because when it began in 1982, breastfeeding in Brazil was almost universal. It was therefore not limited to just one socio-economic group. Thus researchers were able to know that the higher achievers did not come from more affluent families. To be sure their results were valid, however, the researchers adjusted results for family income at birth, parental schooling, genomic ancestry, maternal smoking during pregnancy, age of the mother when the child was born, weight at birth, and the type of delivery.
The results showed that all the breastfed babies were more intelligent (per a standard IQ test), had spent more years in their education, and had higher earnings. The benefits were greater the longer the babies had been breastfed. In adults who had been breastfed for 12 months, the IQ was four points higher than in adults who had been breastfed less than a month. They also had almost a year’s more education and they earned around $105.00 a month more, approximately a third more than the average income level.
Dr. Horta acknowledged that one potential factor could be that mothers who breastfed supported their babies’ development in other ways.
Some people say it is not the effect of breastfeeding but it is the mothers who breastfeed who are different in their motivation or their ability to stimulate the kids.
But he explains there is additional evidence from other studies that mother’s milk is rich in the long-chain polyunsaturated fatty acids that are essential for brain development.
The World Health Organization recommends that mothers breastfeed babies for at least six months. The Brazilian study shows that babies who were breastfed for six months enjoyed most of the benefits that accrued to those who were breastfed for longer. Recognizing that long-term breastfeeding is not a choice every woman will make, Dr. Horta recommends that mothers breastfeed as long as possible.