I think that it would be an interesting topic to research - and we would find as many studies for -as against ????? ( as is often the case)
anyhow I am sure that the op, will do what is best and what works for him and his wife.
"never let the truth get in the way of a good story "
What you believe and what scientific information exists about breast milk are two different things. You are welcome to believe whatever you wish.
This information from the Infant Nutrition Council provides the nutritional profile of breast milk and how it changes over time.Myth 24: Nursing a baby after 12 months is of little value because the quality of breast milk begins to decline after six months.
Fact: The composition of human milk changes to meet the changing needs of baby as he matures. Even when baby is able to take solids, human milk is the primary source of nutrition during the first year. It becomes a supplement to solids during the second year. In addition, it takes between two and six years for a child's immune system to fully mature. Human milk continues to complement and boost the immune system for as long as it is offered.
American Academy of Pediatrics Policy Statement on Breastfeeding and the Use of Human Milk. Pediatrics 1997; 100(6):1035-39.
Goldman, A. Immunologic components in human milk during the second year of lactation. Acta Paediatr Scand 1983; 72:461-62.
Gulick, E. The effects of breastfeeding on toddler health. Ped Nursing1986; 12:51-54.
Innocenti Declaration on the protection, promotion and support of breastfeeding. Ecology of Food and Nutrition 1991; 26:271-73.
Mohrbacher, N., Stock, J. BREASTFEEDING ANSWER BOOK. Schaumburg, Illinois: LLLI, 1997; 164-68.
Saarinen, U. Prolonged breastfeeding as prophylaxis for recurrent Otitis media. Acta Paediatr Scand 1982; 71:567-71. (source)
Finally, I did *qualify* my statement. Either A. you completely ignore that qualification or B. you misunderstand it or C. you didn't read it.
To summarize it,
A. I am not advocating that a person breastfeed exclusively (sole source of nutrition) for X years. I am asserting that it is possible for a person in an extreme circumstance to maintain her children up to the far extreme of human natural weaning as a demonstration that breast milk has everything that a child needs after 6 months to directly refute your *false* information, which the science refutes above.
B. I also asserted that in our modern world, it is of course natural and normal and healthy to introduce foods well before the far side of natural weaning as those foods are available. With this, there are many methods and means of doing this. And, I have advocated that across 4 posts now (including this one).
C. Most of the "ages at which one starts solids" is largely cultural, not scientific or based on actual signs of readiness in the child. That is why I prefer the baby-led approach. It focuses not on cultural, arbitrary ages based on what people "believe" but rather based on scientific information and observation around human development in preparation for eating for nutrition. The web link provided before has plenty of information on it.
Now, I suggest you scientifically validate your beliefs, since I've already validated mine up the yin-yang.