Now that we know breastfeeding does not cause sagging breasts, today, we learned that children who were breastfed having higher IQs.

For years, doctors have stressed the importance of breastfeeding children, which they say can help women lose weight, gave children needed vitamins and nutrients, and more. Now, they can add higher IQs.

More than 3,000 infants who were breastfed participated in the study in Britain and New Zealand. Researchers discovered that breastfed children's IQs were an amazing 6.8 points higher than infants who were not breastfed. They also site a gene called FADS2 to the increase.

The study took a bite out of the nature versus nurture debate by showing that intellectual development is influenced by both environmental and genetic factors.

"There has been some criticism of earlier studies about breastfeeding and IQ that they didn't control for socioeconomic status, or the mother's IQ or other factors," said study co-author Terrie Moffitt, a professor of psychological and brain sciences at Duke University and King's College in London.

"Our findings take an end-run around those arguments by showing the physiological mechanism that accounts for the difference."

This difference remained after researchers were able to rule out the influence of socioeconomic status, the IQ scores of the mother, birth weight and gestational age as factors.

"The argument about intelligence has been about nature versus nurture for at least a century," Moffitt said. "We're finding that nature and nurture work together."

Ninety percent of the children had at least one copy of version of the gene which yielded higher IQ if they were breast-fed.

The IQ scores of the other 10 percent were not influenced by breastfeeding, according to the study published in the Proceedings of the National Academy of Sciences.