Breast-feeding is best for a brainy baby, says study

British researchers have found that mother's milk in the first few months of life can boost children's IQ by seven points.

This applies in nine cases out of ten, where the youngster inherits a common but newly-identified "brain boosting" gene.

The finding adds to the mounting evidence that breast-fed babies are happier, healthier and brighter than those raised on formula milk.

It also helps resolve a long-running dispute about the benefits of breast milk on intelligence - and the role of nature and nurture in IQ.

The findings were welcomed by health campaigners, who say that Britain has one of the lowest rates of breastfeeding in Europe and that too little is done to support and encourage new mothers.

Around a fifth of women choose not to breast feed their babies, while a third of those who do have given up within six months.

The link between breast milk and intelligence was first discovered in 1929 and is often used as an incentive to encourage mothers to feed naturally.

However, a major study by the Medical Research Council last year suggested that the link was a myth.

It found that past research had failed to take into account the mother's background.

Not only were those who breastfeed usually brighter, they were more highly educated, older, better off and provided a more stimulating home environment, it found.

Now two studies suggest that breast milk helps babies whatever their family background.

In one, carried out on 1,037 children in New Zealand, IQ was tested at ages seven, nine, 11 and 13.

DNA samples were gathered from the participants when they reached 18.

The other study looked at 2,232 British twins, whose IQ was measured at five.

Both sets of research found that the IQs of breastfed children were seven points higher, even after their social background was taken into account - so long as they had inherited a particular gene from their parents.

The gene, FADS2, is involved in the way the body processes fatty acids in the diet.

Breastfeeding made no difference to the one in ten children who did not carry the gene variant, according to a team from King's College, London.

Previous research has shown that longchain polyunsaturated fatty acids (Pufas) accumulate in the brain during the months after birth.

They are present in human breast milk, but not cow's milk, and have recently been added to infant formulas.

Pufas are thought to be important to childhood brain development because they are essential for the efficient transmission of nerve messages and help to promote the growth of nerve fibres.

The findings appear in the journal Proceedings of the National Academy of Sciences. Professor Terrie Moffitt, based at the Institute of Psychiatry in London, said: "The argument about intelligence has been about nature versus nurture for at least a century. We're finding that nature and nurture work together.

"Our findings support the idea that the nutritional content of breast milk accounts for the differences seen in human IQ. But it's not a simple allornone connection: it depends to some extent on the genetic makeup of each infant."

In the last decade, many infant formula makers have started adding two Pufas - docosahexaenoic acid (DHA) and arachidonic acid (AA) to their products.

But the children taking part in the gene study were born in 1972-73 in New Zealand and 1994-95 in England, before fatty acid supplementation of infant formula began.

The jury is still out on whether Pufa supplementation has made a difference. However, in laboratory tests, animals given fatty acid supplements have performed better at learning, memory and problem-solving tests.

Past studies have shown that breast-fed babies are less likely to suffer from asthma, eczema, heart disease and obesity later in life.

Rosie Doddes, a breastfeeding adviser for the National Childbirth Trust, said the benefits of breastfeeding to mothers and children were well established.

"In the early months, breastfeeding protects against respiratory and gastrointestinal problems.

"It's up to women to choose whether to breast feed or bottle feed, but we are very concerned that women are not getting the right support and information.

"Rates are relatively low in Britain compared to Europe, and very low compared with the rest of the world."