THE chemical in chillies that makes them hot to taste could be used to combat cancerous tumours, a new study has found.

Dr Andrew Westwell, a senior lecturer in Medicinal Chemistry at the Welsh School of Pharmacy, said the chemical compound capsaicin, that gives spicy food like curry its kick, could hold the key to the next generation of anti-cancer drugs that will kill tumours.

He was an adviser in a study, published in the journal Biochemical and Biophysical Research Communications, that has proven for the first time that capsaicin can kill cells by directly targeting their energy source.

Working in collaboration with the University of Nottingham, Dr Westwell said the beauty of the laboratory test discovery was that the compound would have few or no side effects for the patient.

It could also mean that patients could control or prevent the onset of cancer by eating a diet rich in capsaicin.

Dr Westwell said, "We found that in cancer cells grown in the lab, capsaicin can be a signalling mechanism that instructs cancer cells to die, without the nasty effects of chemotherapy, such as affecting healthy cells or changing DNA.

"But with any potential new drug it needs to be thoroughly tried and tested for around 10 years - although the advantage we do have is that chillies are already eaten by many people and are known to be safe."

Dr Timothy Bates, a member of the Medical Research Council (MRC) College of Experts, said the research team also tested similar compounds on pancreatic cancer, producing similar cell death to that observed with lung cancer cells.

These results are highly significant, as pancreatic cancer is one of the most difficult cancers to treat and has a five-year survival rate of less than 1%.

Dr Bates added, "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 investigation and development of anti-mitochondrial drugs for cancer chemotherapy by our group is unique in the UK and is likely to be extremely significant in man's fight against cancer both here and internationally.

"We are currently seeking industrial partners to enable these agents to be used in clinical trials to treat a variety of cancers."

The breakthrough was welcomed by Cardiff GP Dr Andrew Dearden, chairman of the BMA Welsh GPs Committee.

He said, "This sounds hopeful, although one of the difficulties with cancer is that although every few years we get a study that gives out hope, it proves difficult to turn into a working drug. But at least the evidence is there.

"Obviously there will be a long process to make sure any drug would have maximum good bits and minimum bad bits. I don't think we have any drugs that have no side effects at all."

But Josephine Querido, information officer at Cancer Research UK, stressed that this research did not suggest that eating vast quantities of chilli pepper will help prevent or treat cancer. She said, "The experiments showed that pepper extracts killed cancer cells grown in the laboratory, but these have not yet been tested to see if they are safe and effective in humans."

Cancer Research UK recommends reducing your risk of cancer by eating a healthy, balanced diet, with plenty of vegetables and fruit, she said.

So how can chillies kill off cancer cells?

The study has shown that the family of compounds to which capsaicin belongs, vanilloids, can kill cancer by attacking the mitochondria of the tumour cell, commonly known as its "powerhouse". It which produces ATP, the major energy-containing chemical in the body.

By binding proteins in the cancer cell mitochondria the compound triggers apoptosis, or natural cell death, without harming the healthy surrounding cells.

The development may explain why people living in countries like Mexico and India, who traditionally eat a diet which is very spicy, tend to have lower incidences of many cancers that are prevalent in the Western world.