The study looked at red meat, defined as unprocessed mammalian muscle meat such as beef, pork, or lamb, and at processed meat.

Processed meat refers to meat that has been transformed through salting, curing, fermentation, smoking, or other processes to enhance flavour or improve preservation. Most processed meats contain pork or beef, but might also contain other red meats, poultry, offal (e.g. liver), or meat byproducts such as blood.

According to the study, eating 100g of red meat per day leads to a 17 per cent increased risk of developing colorectal (bowel) cancer.

Similarly, eating 50g of processed meat per day increases the risk by 18 per cent.

These findings are the result of a study by the WHO International Agency for Research on Cancer (IARC) Monograph Working Group.

The scientists looked at more than 800 epidemiological studies that investigated the association of cancer with the consumption of red or processed meat from many countries with diverse ethnicities and diets.

Overall, the Working Group classified the consumption of processed meat as “carcinogenic to humans” on the basis of sufficient evidence for colorectal cancer.

A positive association with the consumption of processed meat was found for stomach cancer.

However, the consumption of unprocessed red meat was classified as “probably carcinogenic to humans”.

In making this evaluation, the Working Group took into consideration all the relevant data, including the substantial epidemiological data showing a positive association between consumption of red meat and colorectal cancer and the strong mechanistic evidence.

Consumption of red meat was also positively associated with pancreatic and with prostate cancer.

Red Meat is Still Good for You

Despite the classification of red meat as being 'probably carcinogenic to humans', it is still good for you when eaten in moderation as it contains high biological-value proteins as well as iron, zinc and B vitamins.

The North American Meat Institute (NAMI), commenting on the IARC findings, said that classifying red and processed meat as cancer “hazards” defies both common sense and numerous studies showing no correlation between meat and cancer and many more studies showing the many health benefits of balanced diets that include meat.

Scientific evidence shows cancer is a complex disease not caused by single foods and that a balanced diet and healthy lifestyle choices are essential to good health.

Betsy Booren, Ph.D., NAMI Vice President of Scientific Affairs, noted: “Followers of the Mediterranean diet eat double the recommended amount of processed meats. People in countries where the Mediterranean diet is followed, like Spain, Italy and France, have some of the longest lifespans in the world and excellent health.”

Dr Booren went on to explain: “Red and processed meat are among 940 agents reviewed by IARC and found to pose some level of theoretical ‘hazard.’ Only one substance, a chemical in yoga pants, has been declared by IARC not to cause cancer,” said Dr Booren.

“IARC says you can enjoy your yoga class, but don’t breathe air (Class I carcinogen), sit near a sun-filled window (Class I), apply aloe vera (Class 2B) if you get a sunburn, drink wine or coffee (Class I and Class 2B), or eat grilled food (Class 2A). And if you are a hairdresser or do shiftwork (both Class 2A), you should seek a new career.”