Prior studies have continually shown that breast feeding is linked to increased IQ in children and adults. In a new long-term study of infants in Pelotas, Brazil not only backs up this study but also shows that breastfeeding is also linked to higher income as well.
"Information on breastfeeding duration was collected very close to the time when weaning happened, so we had a very precise information on the duration of breastfeeding," said study author, Dr. Bernardo Lessa Horta, in a podcast in Lancet.
The study interviewed 5,914 new mothers about breastfeeding and then followed up with them to see how they did. What makes this particular study so unique is researchers were able to follow up with the children of the mothers for 30 years.
"We were able to follow about 68% of the participants, which is a very good follow-up rate," said Lessa Horta. "We observed that breastfeeding was positively associated with performance and intelligence at 30 years old, as well as with education, school achievement and higher monthly incomes."
Lessa Horta said that subjects who had been breastfed for 12 months or more not only saw an increase of about 3.7 points in their IQ, but they also had more years of education and earned approximately 20 percent more than the average income level.
"It's suggesting that the positive effect of breastfeeding on IQ leads to a higher income," he said. "This is our main finding at this moment."
One possible reason for the advantage of breast milk, Lessa Horta added, is that it is "rich in long-chain polyunsaturated fatty acids which are important to brain growth and development." These essential fatty acids are also found in salmon and shellfish and have been added to baby formulas since the 1990s. However, the true benefits of these fatty acids as it pertains to development are still unclear.
However, the study did not measure home life, intellectual stimulation or bonding between mother and child. These key measurements can great affect the development of children.
Joan Wolf, professor at Texas A&M University said, ""This study does not address the very real possibility that mothers who choose to breastfeed, regardless of income or education, distinguish themselves from those who bottle-feed in all kinds of ways that are likely to promote intelligence."
Lessa Horta, however, believes the findings of the study are very clear saying, "The finding supports the promotion of breastfeeding. It's more evidence that besides the clear short term benefits, breastfeeding also has long term consequences in terms of human potential."
