From the Norwegian "Nettavisen" (Internet newspaper):
ECS is now described in Lancet; one of UK's leading medical journals (Sorry, haven't found the link yet).
This syndrome comprises amongst other things higher risk of pulmonary embolism, stroke, venous thrombosis and also an increased risk of catching contageous diseases.
Naturally this is because of the confined space in economy with less possibilities of moving about.
The article at:
www.nettavisen.no/subjects/page?section=21&item=114421
came up after King Harald of Norway booked his holiday trip in Economy..
I'm now eagerly waiting for the first "upgrade on prescription"!