The International Agency for Research on Cancer (IARC), the cancer agency of the World Health Organisation, evaluated the carcinogenicity of the consumption of red meat and processed meat.
This association was observed mainly for colorectal cancer, but associations were also seen for pancreatic cancer and prostate cancer.
Processed meat was classified as carcinogenic to humans, based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer. The consumption of meat varies greatly between countries, with from a few per cent up to 100 per cent of people eating red meat, depending on the country, and somewhat lower proportions eating processed meat.
The experts concluded that each 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by 18 per cent. "For an individual, the risk of developing colorectal cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed," said Dr Kurt Straif, Head of the IARC Monographs Programme.
"In view of the large number of people who consume processed meat, the global impact on cancer incidence is of public health importance," said Straif. The IARC Working Group considered more than 800 studies that investigated associations of more than a dozen types of cancer with the consumption of red meat or processed meat in many countries and populations with diverse diets.
The most influential evidence came from large prospective cohort studies conducted over the past 20 years.
"These findings further support current public health recommendations to limit intake of meat," said Dr Christopher Wild, Director of IARC.
"At the same time, red meat has nutritional value. Therefore, these results are important in enabling governments and international regulatory agencies to conduct risk assessments, in order to balance the risks and benefits of eating red meat and processed meat and to provide the best possible dietary recommendations," said Wild.