By David Derbyshire
A common additive used in bacon and ham could fuel the growth of cancers, research suggests. High doses of inorganic phosphate salts – which are used to enhance the texture and flavour of processed meats – increased the size of tumours in mice.
The chemicals are also added to bread, cakes and cheeses. The research will increase concerns that additives used to boost food industry profits could be contributing to cancer rates.
Eating large amounts of processed meats has already been linked to an increased risk of bowel cancer. The latest findings come from a Seoul National University study into the impact of phosphates on mice which were bred to be vulnerable to lung cancer.
High doses of inorganic phosphate salts can speed up the growth of tumours
The creatures were fed a diet containing 0.5 or 1 per cent phosphate – roughly equivalent to the amount found in human diets.
Those on the high additive diet developed tumours more quickly than those on a conventional diet, the researchers wrote in the American Journal of Respiratory and Critical Care Medicine.
They say there is enough evidence to start looking for a link between phosphates and cancer in people. As well as bulking out processed meats, phosphates are used as a raising agent in baking and an emulsifying agent in cheese. Moderate levels are essential for a healthy body.
However the amount in our diets has been rising steadily over last few decades.
The researchers suspect that phosphates increase the growth of lung tumours by interfering in the chemical signals between cells – and this effect could also apply to cancers in other parts of the body.
Kath Dalmeny of the pressure group Sustain said there is growing evidence that processed meats increase the risk of cancer. 'A major study has linked red meats – and particularly processed meats – to bowel cancer,' she said.
'The idea that lots of these chemicals are being used to add more water into meats so they weigh more and can be sold at higher prices is disturbing.'
However, experts urged caution over using the results of the trials on mice to predict the effect of phosphates on humans.
Professor Stephen Spiro, of the British Lung Foundation, said: 'The authors claim that in mice with lung cancer a diet high in phosphates increases lung cancer growth rates.
'While this may be a relevant observation, it has never been assessed in man. Further study would be required to ascertain any link in humans.'
Dr Kat Arney of Cancer Research UK added: 'Smoking is by far the main cause of lung cancer and quitting is the best way to reduce the risk of this disease.'