Scientists have discovered the key to the ability of spicy foods to kill cancer cells. They found capsaicin, an ingredient of jalapeno peppers, triggers cancer cell death by attacking mitochondria - the cells' energy-generating boiler rooms. The research raises the possibility that other cancer drugs could be developed to target mitochondria. The Nottingham University study features in Biochemical and Biophysical Research Communications. The study showed that the family of molecules to which capsaicin belongs, the vanilloids, bind to proteins in the cancer cell mitochondria to trigger apoptosis, or cell death, without harming surrounding healthy cells. Capsaicin was tested on cultures of human lung cancer cells and on pancreatic cancers. Lead researcher Dr Timothy Bates said: "As these compounds attack the very heart of the tumour cells, we believe that we have in effect discovered a fundamental 'Achilles heel' for all cancers. "The biochemistry of the mitochondria in cancer cells is very different from that in normal cells. "This is an innate selective vulnerability of cancer cells." He said a dose of capsaicin that could cause a cancer cell to enter apoptosis, would not have the same effect on a normal cell.