Breastfeeding has a lot of benefits and should be understood as an important “tool” to keep your baby healthy and happy. It is a well known fact that human milk is protective against various infectious diseases. On the other hand even the best infant formulas on the market will not give your baby the same protection.
There have been numerous studies relating to human milk and its protective qualities and one of them can be accessed here; http://www.ncbi.nlm.nih.gov/pubmed/22125798
This study examined whether exclusive (non-formula supplemented) breastfeeding had the ability to prevent hospitalisation in children under 1 year old. The evidence was very strong for babies under 6 months of age.
In another study which was conducted in Brazil it was confirmed that 87.3% mother breastfed their babies at the age of 30 days (one month of age), 77.5% at the age of 120 days (4 months of age) and 68.6% at the age of 180 days (6 months). The exclusive breastfeeding prevalence was 47.5% at the age of one month, only 17.7% at the age of 4 months and 7.7% above 6 months of age. This study can be found right here; http://www.ncbi.nlm.nih.gov/pubmed/18157367
This trend explains why older babies become more vulnerable to infectious diseases as only 60% on average are continued on human milk beyond the age of 6 months. It is worth considering breastfeeding your baby for much longer than the recommended 6 months if you can.