04/09/2025
The natural term for us humans to breastfeed is anywhere between 2 and 7+ years. Some babies stop earlier, some children carry on for longer. It’s thought that the eruption of the permanent set of teeth (losing your milk teeth) influences this timescale.
Many cultures around the world breastfeed until natural term, including many women in the Western world. This age range is only surprising in cultures that interrupt breastfeeding, often without realising it or knowing which norms are biological and which are cultural.
The concentration of fats and proteins increase as the baby grows into a toddler, along with increased levels of antibacterial and antiviral components such as lysozyme, which is an anti-inflammatory, and destroys bacteria.
Lysozyme increases in concentration from about 6 months old, when babies become more independently mobile and everything (toys, sand, twigs, the cats biscuits?) goes straight in the mouth, and keeps increasing after the first year.
The concentration of Lactoferrin also increases over time. Lactoferrin inhibits the growth of some cancerous cells. It also helps our babies to absorb their own iron stores, whilst binding to the iron in our baby’s body which prevents it from being available to harmful microorganisms that need iron to survive. Lactoferrin also kills the bacteria strep mutans, which causes tooth decay and cavities.
Our body’s immune system takes around 6 years to become fully mature, so the support of the protective factors in human milk until our immune system can fully function on its own seems play a part in the timescale of natural term weaning too.
Longer term breastfeeding is also associated with reduced risk of diseases for the mother, including breast cancer.
We acknowledge that many mothers find it difficult to establish breastfeeding in the first place, that breastfeeding is a multi-layered investment on the part of a mother and that natural term feeding might not feel like - or be - a possibility for many.
Or you might simply not want to. We're not here to tell anyone what to do.
We also acknowledge that lack of information about our biology contributes to the lack of support for mothers when they want to establish - or continue - breastfeeding, but cannot find the help they need from people who understand why it matters so much, or what is normal.
Let's continue to turn that around.
More information and references about how remarkable you are at https://human-milk.com/pages/science-of-breastmilk
