The International Agency for Research on Cancer (IARC) have released their monograph on the carcinogenicity of red and processed meat.
The IARC is funded by the World Health Organisation and is affiliated with numerous international cancer organisations. It is widely regarded as providing the “gold standard” verdict on whether an agent is carcinogenic.
IARC classifies substances in four groups. These are based on the level of evidence supporting the association between the agent and cancer. The groups are:
Group 1: Carcinogenic to humans
Group 2A: Probably carcinogenic to humans
Group 2B: Possibly carcinogenic to humans
Group 3: Not classifiable
Group 4: Not carcinogenic
There are 117 agents currently listed as group 1 carcinogens. These include alcohol, tobacco, asbestos and human papilloma virus.
A group 1 carcinogen is an agent said to cause cancer.
Processed meat is now considered a group 1 carcinogen. Red meat is considered a group 2 carcinogen.
The report has said that each 50g portion of processed meat eaten per day increases the risk of colorectal cancer by 18%. For red meat, each 100g per day probably increases the risk by about 17%.
This risk estimate is a relative increase. The overall lifetime risk is around 5%, so the absolute increase is likely to be less than 1%.
Although processed meat and tobacco are now both group 1 carcinogens, this does not mean they are equally dangerous. It means there is sufficient evidence to reach a conclusion about the relationship between processed meat and cancer risk. Sunlight is a group 1 carcinogen and we don’t recommend you avoid sunlight. Instead it is recommended you follow SunSmart behaviour because the sun has some health benefits.
The report’s findings do not mean everyone should stop eating meat, but it is a good time to reflect on your diet. People should limit their consumption of processed meat, or swap processed meat for other healthier food choices like salads and vegetables.
For people who are concerned about cancer, healthy choices can reduce your risk. This means quitting smoking, maintaining a healthy weight, exercising three times a week, practising SunSmart behaviour, and making healthy food choices where meat is balanced with other components like fresh fruit and vegetables.
Over the summer months, the Cancer Society of New Zealand recommends you slip, slop, slap and wrap in the sun, exercise three times a week, quit smoking, maintain a healthy weight, and keep your alcohol intake to a modest level. When you are next at a barbeque, think about having an extra helping of salad instead of another sausage.