Why is breast milk better?

Where there is plenty of information that speaks of the bonding that breastfeeding creates between mother and baby there are many medical reasons to breastfeed for both the mom and baby. I took the following quote from the WEBMD website to give you an example of the medical benefits to the baby but similar info is available on many different reputable sites. Hope this helps.

Breast milk provides the ideal nutrition for infants. It has the perfect mix of vitamins, protein, and fat -- everything your infant needs to grow. And it's all provided in a form more easily digested than infant formula. Breast milk contains antibodies that help your baby fight off viruses and bacteria. Breastfeeding reduces your baby's risk of having asthma or allergies. Babies who are breastfed exclusively for the first six months, without any formula, have fewer ear infections, respiratory illnesses, and bouts of colic and diarrhea. They also have fewer hospitalizations and trips to the doctor.

Breastfeeding is linked to higher IQ scores in later childhood, especially for babies that were premature. The physical closeness, skin-to-skin touching, and eye contact all help your baby bond with you and feel secure. Breastfed infants are more likely to gain the right amount of weight as they grow rather than become overweight children. Some studies have also shown a link between breastfeeding and a lower risk of sudden infant death syndrome (SIDS), diabetes, obesity, and certain cancers. But more research is needed to confirm these findings.

-WebMD

As well as all that medical stuff there is also the practical stuff:

• Breastfeeding doesn't need to be warmed/cooled to the right temperature.
  
• Breastfeeding doesn't require any sterilising.
  
• Breastfeeding doesn't require any preparation, and is always the right combination of nutrients for your child's age.
• You don't have to remember to pack your breasts when you go out for the day or away on holiday.
  
• You can breastfeed in the dark, whilst lying down in your own, warm, comfortable bed.
  
• It's free
  

There have been a number of articles in the press recently (particularly in the UK) misrepresenting a Norwegian study which has found an association between higher levels of male hormones in pregnancy and the ability to breastfeed after birth.

The papers have extrapolated wildly from this research and gone as far as to say this proves there is no benefit to breast feeding. The scale of this misrepresentation has prompted UNICEF to release an Initiative statement on new breastfeeding research. It makes for interesting reading. Extracts are reproduced below:

The body of evidence for the benefits of breastfeeding is very large and comes from a wide range of studies into many different illnesses, carried out by numerous researchers in many different universities. Systematic reviews of the literature have also been carried out and are especially useful, as they are able to eliminate weak studies and combine the findings of all the high-quality papers in order to demonstrate with the greatest reliability whether a protective effect truly exists. It is important to note that there is variability in the quality and depth of evidence in relation to some illnesses which is why the authors of these reviews tend to call for further research to clarify the finding. It remains the case, however, that the evidence for the advantages of breastfeeding is strong.

[...]

This review carried out in the USA screened over 9,000 papers and used evidence from 400. It refers only to health outcomes in developed countries. The review found that breastfeeding is associated with a significant reduction in the incidence of: acute otitis media, non-specific gastroenteritis, severe lower respiratory tract infections, atopic dermatitis, obesity, type 1 diabetes, type 2 diabetes, childhood leukaemia, sudden infant death syndrome, necrotizing enterocolitis, maternal breast cancer and ovarian cancer.

[...]

It found a significant reduction in the incidence of obesity and overweight and type 2 diabetes. It also found that breastfed babies had lower systolic blood pressure, lower cholesterol and better performance in intelligence tests.

I found this information by following Ben Goldacre on Twitter, he's also the author of Bad Science, which has excellent chapters on various other scare stories including MRSA and MMR. I thoroughly recommend it.

Because it is the optimal source of nutrition and specifically tailored for the needs of a human baby, compared to cow's milk or any other artificial formula.

LLLI has a great collection of articles about the topic: "Benefits of Breastfeeding". - both for the baby, mother and the society as a whole.

I would esepcially recommend the following articles:

What Makes Human Milk Special?

.. and the bigger picture: Nursing The World Back to Health

I also like how breastmilk evolves with the development of the baby and is of different composition when baby is one week old versus one month old. Supposedly it continues to evolve to meet the growing baby's needs. Also, I like the idea of baby tasting some variety from breast milk depending on what I have eaten that day.