Sorry, but you are simply wrong in stating that there is no benefit to the child from extended nursing. Please have a look at this very informative article excerpted below, as well as the references cited therein.
Extended Breastfeeding Fact Sheet
By Kelly Bonyata, BS, IBCLC
http://www.kellymom.com/bf/bfextended/ebf-benefits.html
- The American Academy of Pediatrics recommends that "Breastfeeding should be continued for at least the first year of life and beyond for as long as mutually desired by mother and child... Increased duration of breastfeeding confers significant health and developmental benefits for the child and the mother... There is no upper limit to the duration of breastfeeding and no evidence of psychologic or developmental harm from breastfeeding into the third year of life or longer." (AAP 2005)
- The American Academy of Family Physicians recommends that breastfeeding continue throughout the first year of life and that "Breastfeeding beyond the first year offers considerable benefits to both mother and child, and should continue as long as mutually desired." They also note that "If the child is younger than two years of age, the child is at increased risk of illness if weaned." (AAFP 2001)
- A US Surgeon General has stated that it is a lucky baby who continues to nurse until age two. (Novello 1990)
- The World Health Organization emphasizes the importance of nursing up to two years of age or beyond (WHO 1992, WHO 2002).
- Scientific research by Katherine A. Dettwyler, PhD shows that 2.5 to 7.0 years of nursing is what our children have been designed to expect (Dettwyler 1995).
- Nursing toddlers between the ages of 16 and 30 months have been found to have fewer illnesses and illnesses of shorter duration than their non-nursing peers (Gulick 1986).
- "Antibodies are abundant in human milk throughout lactation" (Nutrition During Lactation 1991; p. 134). In fact, some of the immune factors in breastmilk increase in concentration during the second year and also during the weaning process. (Goldman 1983, Goldman & Goldblum 1983, Institute of Medicine 1991).
- Per the World Health Organization, "a modest increase in breastfeeding rates could prevent up to 10% of all deaths of children under five: Breastfeeding plays an essential and sometimes underestimated role in the treatment and prevention of childhood illness." [emphasis added]
http://www.kellymom.com/bf/bfextended/ebf-benefits.html
References: Immunological Benefits
Immunological Protection by Kathryn Orlinsky
Briend A, Wojtyniak B and Rowland MG. Breast feeding, nutritional state, and child survival in rural Bangladesh. Br Med J (Clin Res Ed). 1988 Mar 26;296(6626):879-82.
Goldman AS et al. Immunologic components in human milk during weaning. Acta Paediatr Scand. 1983 Jan;72(1):133-4.
Goldman AS, Goldblum RM, Garza C. Immunologic components in human milk during the second year of lactation. Acta Paediatr Scand. 1983 May;72(3):461-2.
Gulick EE. The effects of breastfeeding on toddler health. Pediatr Nurs. 1986 Jan-Feb;12(1):51-4.
Hamosh M. Bioactive factors in human milk. Pediatr Clin North Am 2001 Feb;48(1):69-86.
Hamosh M, Dewey, Garza C, et al: Nutrition During Lactation. Institute of Medicine, Washington, DC, National Academy Press, 1991, pp. 133-140. This book is available free from the HRSA Information Center (look under Nutrition publications).
Lawrence R and Lawrence R. Breastfeeding: A Guide for the Medical Profession, 5th ed. St. Louis: Mosby, 1999, p. 159-195. See particularly Table 5-2 on p. 169: "Concentration of immunologic components in human milk collected during second year of lactation"
Palti H, Mansbach I, Pridan H, Adler B, Palti Z. Episodes of illness in breast-fed and bottle-fed infants in Jerusalem. Isr J Med Sci 1984 May;20(5):395-9.
One of the resources cited above is Katherine Dettwyler, a biocultural anthropologist who has done extensive research on extended breastfeeding. Her website is also extremely informative. Here is an excerpt:
"At this point (2005), all of the research that has been conducted on the health and cognitive consequences of different lengths of breastfeeding shows steadily increasing benefits the longer a child is breastfed up to the age of 2 years, and no negative consequences. No research has been conducted on the physical, emotional, or psychological health of children breastfed longer than 2 years. Thus, while there is no research-based proof that breastfeeding a child for 3 years provides statistically significant health or cognitive benefits compared to breastfeeding a child for only two years, there is no research to show that breastfeeding a child for 3 years (or 4-5-6-7-8-9 years) causes any sort of physical, psychological or emotional harm to the child. This has recently been confirmed in the 2005 American Academy of Pediatrics "Recommendations for breastfeeding the healthy term infant" (see below).
...
In conclusion, there is no research to support a claim that breastfeeding a child at any age is in any way harmful to a child . On the contrary, my research suggests that the best outcomes, in terms of health, cognitive, and emotional development, are the result of children being allowed to breastfeed as long as they need/want to. Around the world, most children self-wean between the ages of 3 and 5 years, but given that the underlying physiological norm is to breastfeed up to 6-7 years, it is quite normal for children to continue to breastfeed to this age as well, and the occasional "normally" developing child will nurse even longer. Children who nurse for more than a year or two tend to regard their mother's breasts as sources of love and nurturance and comfort, and are more or less immune to the broader society's attempts to culturally define breasts as sex objects. "
I hope this information dispells some of the misconceptions out there about nursing toddlers.