Red meat and processed meat
You may have seen a lot of media coverage around research published by The International Agency for Research on Cancer (IARC), the cancer agency of the World Health Organisation. IARC have said that processed meat is now classified as a ‘definite’ cause of cancer and red meat as a ‘probable’ cause of cancer.
Here is a short Q&A to explain these latest findings further.
Firstly what are ‘red’ and ‘processed’ meats?
‘Red’ meat is any meat that has a dark red colour before it is cooked – this includes meats such as beef, lamb and pork.
‘Processed’ meat is meat that is not sold fresh but has been preserved. For example, the meat may have been smoked, cured, or had chemical preservatives added. This includes meats like bacon, sausages, hot dogs, hams, rashers, salami, and pepperoni.
What does this research from IARC say about processed meat and red meat?
According to IARC, processed meat has now been classified as a ‘definite’ cause of cancer (or Group 1 carcinogen) – the same group which includes smoking and alcohol. This group contains substances where science has shown that they definitely cause cancer however it does not rank them in order of how much cancer they cause. Red meat has been deemed a ‘probable’ cause of cancer (or a Group 2a carcinogen). This group contains substances where there is evidence of a link to cancer but no substantial proof. Again there is no ranking in this group.
The IARC classifications describe the levels of scientific confidence that red and processed meat are linked to cancer but not how much cancer they cause.
Does eating ‘red’ or ‘processed’ meat really increase my risk of cancer?
The occasional eating of meat and meat products has little negative impact on day to day health. Meat is an important source of protein and other nutrients for the average Irish diet but you should be aware that if you eat a lot of processed and red meat regularly and over much of your life, then you do slightly but measurably increase your risk of getting bowel cancer.
There is strong scientific evidence to suggest that by avoiding or limiting the consumption of processed meat, and reducing your intake of red meat, you can help reduce your risk of cancer, particularly bowel cancer.
Avoiding or limiting processed and red meats is just one way you can reduce your risk of cancer. The European Code Against Cancer outlines healthier lifestyle choices than can help you reduce your risk of certain cancers and improve your general health. This includes:
- not smoking
- limiting your alcohol intake
- eating a healthy diet
- being physically active
- being a healthy weight
Why not watch our video on how you can reduce your risk of cancer?
What types of cancers are linked or associated with eating red meat?
The strongest, but still limited, evidence for an association with eating red meat is for bowel cancer. There is also evidence of links with pancreatic cancer and prostate cancer.
What types of cancers are linked or associated with eating processed meat?
The IARC research concluded that eating processed meat can increase the risk of bowel cancer. An association with stomach cancer was also seen, but the evidence for the link with that form of the disease is not as conclusive.
Could you quantify the risk of eating red meat and processed meat?
The consumption of processed meat was associated with small increases in the risk of cancer. For every 50 gram portion of processed meat eaten daily over the course of a persons life, the risk of bowel cancer increases by about 18 per cent.
The cancer risk relating to eating red meat is more difficult to estimate because the evidence that red meat causes cancer is not as strong. The studies suggest, however, that the risk of bowel cancer could increase by 17 per cent for every 100 gram portion of red meat eaten daily.
How much red meat can I eat? Do I have to give it up entirely?
Red meat is fine in moderation, it is rich in valuable nutrients like protein and iron. When taken in large amounts however, it can increase your risk of certain cancers. Therefore a reasonable approximate guide would be to consider limiting your intake to 500g or 18oz of cooked lean red meat per week (800g/28oz of lean raw meat). This can be spilt into four or five small portions over the week.
Some examples of typical meat servings:
- Pork or lamb chop - 75g
- ‘Quarterpounder’ beef burger - 90g
- Medium portion of roast beef, lamb or pork - 90g
- Medium Steak - 145g
How much processed meat can I eat?
On the whole, occasionally eating reasonable and moderate amounts of processed meats as part of a mixed and healthy diet including vegetables and fruits will have only a little impact on the likelihood of getting bowel cancer. The cancer risks of processed meats are a little higher than those for red meat, so, ideally , one should consider reducing portion sizes of processed meats, eating processed meats less regularly or avoiding them altogether.
What about white meats and fish?
No cancer associations have been identified with white meats such as fresh chicken or turkey, or fish.
What makes red meat and processed meat increase the risk of cancer?
Meat consists of multiple components, such as haem iron. Meat can also contain chemicals that form during meat processing or cooking. Some of these chemicals are known or suspected to cause cancer, because these chemicals can, over prolonged periods of exposure, be shown to cause damage to the DNA in the cells in our bodies.
How does eating processed meat compare to smoking when it comes to increasing your risk of cancer?
This new research from IARC says that the evidence which shows that processed meat increases the risk of cancer is as scientifically well established as that around tobacco and the increased risk of cancer as a result of smoking. However, the magnitude of the risk of cancer as a result of smoking remains much greater than the risk posed from eating processed meat and red meat.
In Europe, smoking causes an estimated nine in ten of lung cancers. While this IARC research in relation to processed meat estimates that if a person ate a diet rich in processed meats daily over their lifetime, each 50 gram portion of processed meat increases the lifetime risk of bowel cancer by 18 per cent. To put it another way, in Ireland five in every hundred people will get bowel cancer over their lifetime. If everyone in Ireland ate a diet with 50 grams more of a processed meat per day every day, then we would expect the number of bowel cancers to rise to six in every hundred.
That means that never smoking or giving up smoking is by far the most important thing to do if you want to reduce your risk of cancer.
A mixed diet can include meat in moderation without major health or cancer concerns. Broadly the typical Irish diet probably contains a bit too much red meat so we would all be advised to look at the amount and regularity of meat intake and consider eating meat in a bit more moderation.
Because processed meats contact additional chemicals, there is a small additional increased risk of certain cancers, particularly of the bowel, so we should try to eat less processed meats and eat them less regularly to reduce that risk.