The conclusion from Dr Brian Green, Dr William Crowe and Professor Chris Elliott OBE flew in the face of advice from the World Health Organisation (WHO), which classified all processed meat as a carcinogen – capable of causing cancer – in 2015.
The results – published in the scientific journal Nutrients – were based on a review of existing studies into the relation between meat consumption and cancer.
Initial research into the studies found that only half found evidence of a link between processed meat and colorectal cancer (CRC), which the report said explained the contradictory claims in media in recent years.
Nitrates in meat
However, research into the consumption of meat containing sodium nitrite found the link to cancer increased from half to just under two-thirds (65%).
“When we looked at nitrite-containing processed meat in isolation – which is the first time this has been done in a comprehensive study – the results were much clearer,” explained Dr William Crowe.
Co-author Chris Elliott said this latest research brought more clarity to what has been a confusing area for the food industry and the public.
“Because there have been conflicting claims in the scientific community and the media about which types of meat may be carcinogenic, this study couldn’t have come at a better time,” said Elliott. “It brings much-needed rigour and clarity and points the way for further research in this area.”
Reassessing the risk
The IGFS researchers have now called for the health risks of processed meat containing nitrates and those without to be defined separately.
Brian Green added: “We hope that future research investigating the link between diet and CRC will consider each type of meat individually rather than grouping them together. Our findings clearly show that not all processed meats, for example, carry the same level of risk.”
The IGFS team intended following up its evidence review with a pre-clinical study probing the effects of nitrite-containing meat on CRC.