Patricia:
Nutritional benefits of breastfeeding are just the same at any age: best
quality protein, non-allergenic, huge quantities of essential long chain
fatty acids, best iron absorption among all known foods, all the vitamins
and minerals in optimal concentrations. If this guardian (have mothers a
guardian in the USA? oh, dear!) is implying "prove me that your son will
die if weaned, or wean NOW!), tha same thing can be said of any other food.
Do he need a reference about nutritional benefit of apples, bread, cheese,
chocolate, chop-suey, hot dogs or cola-loca? Will the poor child be allowed
to eat something, or just be starved until references are found?
The problem is not of references, but of prejudices.
Fiona:
This "risk of bf after a year" comes from a British paper, maybe in BMJ
about 2 years ago? (sorry, forgot reference). Hearth problems of several
hundred Scottish people (aged 60, I think) was correlated with type of
feeding, as stated in old charts. Breastfeeding was associated with a lower
risk of hearth disease; but breastfeeding longer than 1 year was associated
with a higher risk. Of course, this kind of retroretroretrospective study
is only useful to raise hypothesis: to many factors are not taken into
account (social and cultural variables associated with lenght of BF at
these remote times, parental smoking, family diet in childhood... wath
about the people who has dead before reaching the age to enter the study,
were they bottle- or breastfed?) Even if this was confirmed (and I doubt it
will), the risk of hearth disease should be compared to other risks of
short breastfeeding (breast cancer and osteoporosis in the mother, diabetes
and otitis in the child...)
        Best wishes             Carlos Gonzalez
                                Barcelona