6 Months?!? Why Wait So Long?

Everywhere I look and everyone I talk to has a different opinion of when to start babies on solid foods. Most of the literature I have come across says 4-6 months, but I am starting to see more and more recommendations to wait until 6 months- and their reasoning seems very sound.

One of my favorite breastfeeding resources, kellymom.com, explains that during 4-6 months of age, a baby’s intestinal lining begins to change. When they are born, they possess an “open gut” meaning that proteins and pathogens can enter into the bloodstream. This can be a good thing for breastfed babies because it allows all of the beneficial antibodies to enter the bloodstream and help fight off potential infections. The problem happens when the baby still has an "open gut" and proteins from food enter into the bloodstream. The immune system recognizes the protein as a foreign organism and may produce an antibody to fight it off, thus making a food allergy more likely. Because there is no way to know if their gut has closed yet by outward physical signs, waiting until 6 months increases the likelihood that their gut has matured and allergy risk is (theoretically) much lower.

Diagram from kellymom.com showing the difference between "open" and "closed" gut

To me this is the most important reason to wait, but other reasons include:

1. Baby should be able to sit up with very little assistance (which tends to happen around 6 months) to decrease risk of choking.

2. Teething and cutting teeth typically does not start until around 6 months. The drool has enzymes that help to digest the solid foods.

3. Young babies still have a tongue-thrust reflex that will push out anything that hits the tongue (making it harder to feed). Their swallowing mechanism is immature making it difficult to move food from the front to the back of their mouth. By 4-6 months, the tongue-thrust reflex begins to diminish and the swallowing mechanism allows them to move the food around better.

4. Exclusive breastfeeding (no other foods) for 6 months may reduce later risk of obesity. See http://www.ncbi.nlm.nih.gov/pubmed/15737952?dopt=Abstract for more info.