Breast milk is being used to fight cancer after scientists accidentally discovered it contains a substance that kills tumour cells. 

科学家们意外发现母乳中含有能杀死肿瘤细胞的物质后，正试图通过母乳来对抗癌症。

Trials in patients with bladder cancer have already yielded promising results and researchers believe the compound breast milk contains - nicknamed Hamlet - will also help tackle bowel cancer and cervical cancer. 

They also say it homes in on cancer cells while leaving healthy cells unharmed - so it has none of the debilitating side effects of chemotherapy. 

Professor Catharina Svanborg, who made the initial discovery, said: 'There's something magical about Hamlet's ability to target tumour cells and kill them.' 

She said human breast milk contained a protein called alpha-lactalbumin, which is transformed into a cancer-fighting agent when in the gut. 

Prof Svanborg, an immunologist at Lund University in Sweden, made the chance discovery that the substance kills tumour cells when working on antibiotics. 

She said: 'We were looking for novel antimicrobial agents, and new breast milk is a very good source of these. During one experiment we needed human cells and bacteria to be present, and we chose human tumour cells for practical reasons. 

'To our amazement, when we added this compound of milk, the tumour cells died. It was a totally serendipitous discovery.' 

The substance attacks cancer cells in numerous ways - first evading the cell's outer defences, then targeting the 'power station' mitochondria and the 'instruction manual' nucleus. These actions cut off the cell's energy source and 'programme' it to commit suicide, in a process called apoptosis.