Interestingly bloodless surgery is now seen as the best option when it comes to surgery. The fact is people recover faster and live longer when they have surgery without blood. Blood can often complicate things and slow down recovery times and often even make things worse. Doctors are just not keen on giving it as it's far more expensive. But with the advances in medical science in the past few years more and more doctors are realising it's the way to go.
My dad has a triple heart bypass last year. He didn't have a drop of blood. Out of the six others men on his ward, he recovered the fastest depsite being the second oldest.
It seems completely irrational to me. Where the Israelites were commanded not to eat animals with the life blood in them, wasn't this supposed to mean don't eat them whilst they are still alive, not a ban on eating blood per se? Besides which, even if the ban on eating blood is a valid one, how does this translate to the forbidding of blood transfusions? Seems to me this is yet another case of strict adherence to the letter of a law with no understanding of what that law was for. The spirit of the law would not ban blood transfusions that save countless lives.
I was told recently by a JW that blood (and other biological materials left over from life) must not be tampered with or used for transfusions, etc partly for genetic reasons and also because they believe that left-over blood, skin, flesh, etc somehow gets broken down and recycled to form biological matter for hosting new life when it comes into this world. In the case of 'genetics' he said that although the blood used in a transfusion may be good there could be underlying genetic problems that may not necessarily affect that person but the genes could be passed on to the children of the person who had the transfusion (ie hereditary).