Assertion: caffeine | /r/CapableOf | act as vasoconstrictor
Facets:
Source sentences:
text: Caffeine has been suspected of contributing to menstrual pain and cramping because it can act as a vasoconstrictor -- mildly constricting blood flow which can lead to pain.
text: Caffeine can act as a vasoconstrictor, a substance that narrows blood vessels, so it has been suspected to contribute to chest pain, blood pressure or heart disease.