According to new research today, babies who are breast-fed cry more, laugh less and generally have ‘more challenging temperaments’ than bottle-fed babies.

Igniting the debate on whether ‘breast is best’, researchers from the Medical Research Council Epidemiology Unit in Cambridge claim that breast-fed babies are harder to handle due to their ‘dynamic communication’ with their mother, whereas bottle-fed babies are ‘more content’.

The study investigated the temperament of 316 three-month-old babies who were exclusively breast-fed, bottle-fed or mixed-fed, based on a Revised Infant Behaviour Questionnaire completed by their mothers.

Researchers discovered that of the 316 babies studied, breastfed and mixed-fed infants were rated as being the most challenging throughout three broad areas of research. The study added that there were no identified difference in behaviour between boys and girls.

"In particular, compared to formula-fed infants, breast-fed infants were reported to show greater distress, less smiling, laughing and vocalisation, to be slower to calm down following distress or excitement, and more difficult to soothe by care givers,” says study authors, published in the Public Library of Science ONE.

“Infants who were breastfed or mixed-fed at three months of age were rated by their mothers as having overall more challenging temperaments."

Researchers believe that the findings could explain why three quarters of UK mothers start out breastfeeding but only a third continue doing so after four months.

The study, which enrolled a total of 1,526 babies into the Cambridge Baby Growth Study, believes the results could be because bottle-feeding is akin to ‘comfort eating’ and therefore produces quieter, more content babies as they’re over-nourished and gaining weight rapidly as a result.

“There is an overwhelming body of evidence supporting breastfeeding as the normal and most healthy form of infant nutrition, and our findings do not contradict this. Bottle-fed babies may appear more content, but research suggests that these infants may be over-nourished and gain weight too quickly. Our findings are essentially similar to other stages of life; people often find that eating is comforting,” adds study leader, Dr Ken Ong.

However, not all medical experts agree with these findings, as independent antenatal teacher and doula, Janine Rudin from Birth Basics tells The Huffington Post: “I am very surprised by this research as my experience as a mother and as a parenting specialist is the completely opposite of this. Breast-fed babies often seem to cry less and are easier to settle, especially when teething and unwell, because they gain a lot of comfort from being at the breast, it is not just about food.

“They are more likely to be demand fed as well, which often means their needs are met quickly. My concern is for parents because I am not sure how beneficial this type of research is. There is a great deal of pressure on parents in our society to follow all the rules and to do the right thing – parents need to be supported whether they choose to formula feed or breastfeed.”

Anne Richley, a midwife for Practical Parenting magazine, also questions the research: “I'm intrigued as it's highly unlikely that any baby fed by natural means would do less well than a baby fed by artificial means,” she told The Huffington Post.

“There are recent reports that because of the bond fostered between mums and babies during breastfeeding, the mums are more supportive and attentive of their children. I've always believed that when a baby’s needs are responded to, in the long run you'll have a more secure child.”

Annette Briley, a consultant midwife for baby charity, Tommy’s, says, “Breast milk remains the ideal food for babies, and especially in the early stages babies can appear less settled and more demanding than their bottle-fed counterparts. The advantages of breastfeeding are well documented in terms of both short and long term health consequences for mother and child, but no one should expect it to be “easy”, especially in the initial stages.

“If this research helps women realise that they may face difficulties, and that babies do get upset and frustrated at times – they could be teething, or just feeling under the weather - and that this is normal then maybe more women will be better prepared for the trials and tribulations of breastfeeding! It may also help those around the new mum and baby to realise she will need their help and support to persevere. All babies have times when they are tetchy and difficult regardless of the way they are fed,” Annette told The Huffington Post.

Rosie Dodds, senior policy adviser at the National Childbirth Trust, tells the Press Association, "Mothers and babies may experience starting to breastfeed as demanding or stressful in this society where bottle feeding is seen as the norm and breastfeeding is unfamiliar to many new parents.

“It would be interesting to compare this with countries where almost all babies are breast-fed. We often hear from mothers who say that once both they and their baby got the hang of it, breastfeeding was a breeze.

“NCT provides information and support through groups, one-to-one help, our telephone line and website. We have consistently called for more support for new parents and for breastfeeding from governments, local authorities, health services, friends, family and employers.”