blake murphy wrote:
>
> my father was recently put on coumadin, for which i understand the
> generic is warfarin, a blood thinner or anti-coagulant (and yes, i
> know, a major ingredient in some rat poisons). there were some food
> restrictions (leafy green vegetables, etc.), due to large amounts of
> vitamin k, which apparently reduces the effect. those didn't bother
> him, but 'no onions' is chafing his knickers. (paradoxically, onions
> themselves seem to have an anticoagulant effect.)
>
> apparently, cooked onions are less bad, i presume because cooking
> destroys some of the viatmin k.

This article specifically mentions fried and boiled
onions are to be avoided:

http://www.dietitian.com/vitamink.html

This article has a table which lists white and yellow
onions as low in K, but green onions as high in K.

http://www.drgourmet.com/warfarin/vegetables.shtml