I remember watching this black and white movie about a lady who had to kill and eat the he

I remember watching this black and white movie about a lady who had to kill and eat the heart of men to stay younger and look beautiful. But the look only last for a short period of time. Then she has to kill again to maintain the look. But after each killing, she gets older once it wears off. After the 7th or 8th killing, she looks over 100 and had to kill again. But her time is up cuz she no longer has the strength to kill. Can anybody tell me the title of this movie?