This is a couple things I wrote up while studying about the blood issue. Especially on the quote from Tertullian.
Watchtower 2004 - 6/15 - Be Guided by the Living God
8 How did the early Christians understand and act on God’s guidance about blood? Recall Clarke’s comment: “Under the Gospel it should not be eaten, because it should ever be considered as representing the blood which has been shed for the remission of sins.” History confirms that the early Christians treated the matter seriously. Tertullian wrote: “Consider those who with greedy thirst, at a show in the arena, take the fresh blood of wicked criminals . . . and carry it off to heal their epilepsy.” Whereas pagans consumed blood, Tertullian said that Christians “do not even have the blood of animals at [their] meals . . . At the trials of Christians you offer them sausages filled with blood. You are convinced, of course, that [it] is unlawful for them.” Yes, despite threats of death, Christians would not consume blood. God’s guidance was that important to them.
9 Some may imagine that the governing body simply meant that Christians were not to eat or drink blood directly nor to eat unbled meat or food mixed with blood. Granted, that was the first import of God’s command to Noah. And the apostolic decree did tell Christians to ‘keep themselves from things strangled,’ meat with blood left in it. (Genesis 9:3, 4; Acts 21:25) However, the early Christians knew that more was involved. Sometimes blood was taken in for medical reasons. Tertullian noted that in an effort to cure epilepsy, some pagans consumed fresh blood. And there may have been other uses of blood to treat disease or supposedly improve health. Hence, for Christians, shunning blood included not taking it in for “medical” reasons. They maintained that stand even if it put their life at risk.
I found 2 other translations of what was quoted.
Translation 1:
As for feeding upon blood and tragic dishes of that kind, read whether it is not somewhere related (it is in Herodotus 25, I think) that certain nations have appointed the tasting of blood, drawn from the arms of both parties, for the ratification of a treaty. Some such tasting there was, too, under Catiline. They say also that among certain Scythian tribes a dead person is eaten by his own relatives. I am going far afield. To-day, at home, blood from an incised thigh, caught in a shield and given to her own worshippers, seals those dedicated to Bellona. What about those, too, who for the cure of epilepsy at the gladiatorial show in the arena drink with greedy thirst the fresh blood flowing from the throats of the criminals?
Translation 2:
Those, too, who at the gladiator shows, for the cure of epilepsy, quaff with greedy thirst the blood of criminals slain in the arena, as it flows fresh from the wound, and then rush off'to whom do they belong?
There was also NO mention of "threats of death", as the WT states, if Christians wouldn't consume blood. It only says this: "Lastly, among the tests applied to the Christians you present to them sausage-skins filled with blood, simply because you are quite certain that it is unlawful for them, and you wish through it to inveigle them into error."