I once went to a talk on childhood ear infections with a local pediatrician
(in central New Jersey, USA) and I got up the nerve to ask the doc whether
breastfeeding had a preventative effect.  He said that he has not found that
to be the case in his practice, that all babies/toddlers/children are prone in
the winter months because of all the colds "going around" when people are
cooped up together spreading germs.  Of course, I have to wonder what
percentage of his ped practice breastfeeds past infancy...but I don't know.
  I have thought about his answer for a long time since then, and as I now
live in sunny south Florida, I would expect that children here would have
barely *any* ear infections since we don't have a real "winter".  It never
gets cold enough for us all to be cooped up together!   Actually, we get
cooped up in the summer when it's too hot to go out, but that is not ear
infection "season".  The fact is, lots of children get colds here, and lots of
children get ear infections.   My breastfed children have had one each, and
that at two years and four years old respectively, and both occurred when it
was quite warm outside and just the usual sharing of germs with other
children.  I just can't imagine that this is coincidental to breastfeeding!
  Neither of my children drinks cow's milk, except for what it takes to get
their cereal wet- and this is probably in some way related to their generally
good health.

Lisa Jones, LLLL in Wellington, sunny south Florida, USA