To evaluate new insights into the health benefits of breastfeeding - for both mother and child - the Dutch National Institute for Public Health and the Environment (RIVM) systematically reviewed relevant literature and peer-reviewed articles.

They summarized information from 44 peer-reviewed articles. This review focused on Western countries, with the strength of evidence based on WHO criteria - ranging in order of importance, from "convincing", "probable" "possible" and "insufficient" to "conflicting" and "no evidence".

Lowering risk for babies

Convincing evidence showed that being breastfed as a baby lowers the risk of gastrointestinal and respiratory tract infections, as well as ear infections (otitis media). These effects continue into early childhood. 

One step lower on the WHO scale - but still impressive - is the probable evidence of the protective effect of breastfeeding on a child's risk of obesity, asthma and wheezing - especially during early childhood. Probable evidence also showed the benefits of breastfeeding on a child's intellectual and motor development. 

Children were found to be protected, with possible evidence, from childhood cancers, Crohn's disease, ulcerative colitis, and diabetes mellitus type 1 and 2 - as well as reduced risk of sudden infant death syndrome and leukemia.

Valuable insights

The possible protection by breastfeeding from inflammatory bowel disease, helicobacter pylori infection and diabetes mellitus type 2 is a new insight gained in this report. In the case of diabetes mellitus type 2, protection could be due to the effect of breastfeeding on obesity later in life - as this form of diabetes is related to obesity.

In many cases, the protection offered by breastfeeding could be due to the antibodies contained in breastmilk and colostrum. However, the report showed that breastfeeding fails to protect babies from all infections. For example, evidence of a reduced risk of urinary tract infections and influenza was found to be insufficient. 

Compared with the previous RIVM report, evidence for protection against atopic diseases and eczema has dropped from possible/probable to conflicting. Hopefully new and better research can lead to improvements in our knowledge of the effect of breastfeeding on these conditions.

Benefits for mothers

Mothers also gain certain benefits from breastfeeding their child. Even though the evidence may not be "convincing" on the scale set up by the WHO, there was evidence of the next best thing: probable evidence.

In this case, probable evidence was found for a level of protection from diabetes mellitus type 2 and rheumatoid arthritis. The review also showed possible evidence that breastfeeding could protect mothers from ovarian cancer and hip fractures. 

New in this report was the finding of probable protection from hypertension and possible protection from postpartum weight retention. On the other hand, no evidence was found for protection against postpartum fatigue and symptoms of depression - which emphasizes the importance of other forms of care when dealing with these conditions. 

Evidence about protection from premenopausal breast cancer shifted from possible/probable in the previous report to conflicting. Postmenopausal breast cancer evidence also dropped to conflicting. Hopefully future research will improve our knowledge of these conditions in relation to breastfeeding.