A Thought

I've had a thought on zombies and vampires in popular culture and the way society has been progressing. Vampires are of the old country - even the updated versions stay necessarily old-fashioned. Most of the individual vampires are centuries old. Zombies can be created by modern viruses, etc. So zombies are more modern that way.
But I've noticed something more subtle. Vampires feed on blood, which is kind of equivalent to life force, or liquid life running through your veins. It makes sense that people would fear losing it. It is something that can be lost without really noticing it too much (unlike, say, a limb), but that loss of can kill you. But it's also been recognized as such for a long, long time, and been very important. In a time when one method of healing was to bleed people, you know blood was important.
Nowadays, we have zombies claiming popularity. Zombies do not eat blood. In most of the movies we have seen, they eat flesh. However, in pop culture (and at least one classic movie we haven't seen), zombies eat brains. Is it because now, in the 20th and 21st centuries, we value thinking and cognitive ability so much that the loss of one's brain is scarier than the loss of one's blood? Probably not entirely, but maybe somewhat. That's all.