According to a new long-term study, babies who are breastfed longer might have higher IQ as adults. The study compared to babies who were breastfed for less than a month, babies who were breastfed for a year or longer and they scored four IQ points higher on average.

Conducted by Professor Cesar G Victora and published in The Lancet Global Health, the study included a sample of 3,500 babies from different backgrounds and social classes.

Breastfeeding may have long-term effects on intelligence in a population without strong social patterning of breastfeeding.

What's more, babies who were breastfed for longer were more likely to earn a higher wage and be in education for a longer time.