By Linia Patel
The headlines following the release of the World Health Organization’s report on meat and cancer last week made for pretty scary reading. Even if you don’t knock back the bacon sandwiches, you’ve probably been left wondering if you're eating too much red meat, or even contemplating becoming vegetarian. Here I'll explore the findings from the report and hopefully make things more clear.
Setting the context
The new report comes from IARC – the International Agency for Research on Cancer, an independent body of experts tasked by the WHO to review the evidence between meat and cancer risk. The panel reviewed around 800 pieces of evidence from across the globe and they concluded that there was enough evidence to class processed meat as a class one carcinogen (cancer forming agent), the same as tobacco, alcohol, air pollution and UV radiation. Red meat was ranked by the IARC as a class 2A carcinogen, same as petroleum, chemotherapy drugs, coconut oil and shift working patterns.
What is key to understand is that just because tobacco and processed meat are in the same group, it doesn’t mean they carry the same risk. Being ranked is only part of the story. The other part is how much you are exposed to the carcinogen.
Is it the end of bacon butties, like this one from Le Swine?
What you need to know
A good place to begin is to understand some key definitions.
- Processed meat refers to products that been cured, salted, smoked, or otherwise preserved in some way. Included in this group are things like cold cut sandwich meats, bacon, sausages, hot dogs, ham, salami, and pepperoni. Essentially it means it has been processed by adding something to it. Grinding or mincing doesn’t make it a ‘processed meat.’ When meat is preserved by smoking, curing or salting, or by the addition of preservatives, carcinogens can be formed. These substances can damage cells in the body, leading to the development of cancer.
- Red meat is beef, lamb and pork. One possible reason that red meat is linked to cancer is that the compound that gives red meat its colour, haem, may damage the lining of the bowel. However, its also worth bearing in mind the way you cook meat makes a difference (in short, burnt or very well cooked meats likely carry more risk).
Secondly, you need to understand the risk. The reason for this is the categorization explains how likely something is to cause cancer, but not how many cancers if causes. For example the research indicates that smoking causes 19% of all cancers. If we all stopped smoking there would be 64,440 fewer cases. If we take processed meat and cancer, the research estimates that red and processed meat cause 3% of cancers. So if we stopped eating processed meat there would be 8,800 fewer cases. Most smokers expose their body to tobacco multiple times a day. When it comes to processed meat, how often you have it matters.
So how much is too much?
The IARC report concluded that if you ate 50g of processed meat a day (around 3 rashers of bacon or 2 big slices of ham) per day you have around a 17% higher risk of developing bowel cancer compared to those who ate none. This might sound like a lot, but actually when you put it into context of your absolute risk of developing bowel cancer then you start seeing this the risk if lowered. Your risk of developing bowel cancer is low (around 6% in your lifetime). So if you eat 50g of processed red meat a day this increases your risk from 6% to 7%. This is more or less the same increase in risk as being obese or not exercising.
For red meat, the report showed that for every 100g serving a day of red meat, the relative risk is 1.17, so around the same for processed meat. However, how many of us actually eat that much red meat a day? Dietary surveys show that this is around 24% of men and 9% of women. The recommended daily allowance of processed and red meat is 70g per day. Data shows that on average in the UK we are eating about 71g of meat per day, which is within the recommended guidelines.
Although this is a new report, this isn’t new knowledge (although it received a lot of coverage!) and more importantly it actually doesn’t change my recommendations. We always have to think about it the bigger picture. Keep things in perspective. The bottom line is that eating red meat is not as bad as smoking. However, if you eat a lot of processed meat, then yes, reducing your intake might help you reduce your risk of bowel cancer, but so will losing weight, exercising regularly, eating more vegetables and fruit and so on.
It’s also important to remember that lean red meat is full of vital nutrients like iron and zinc, which we need to include in our diet. So if you eat red meat, it’s ok to keep eating it in moderation as part of a healthy diet. If you choose not to eat it, then that’s ok too – just make sure you get good iron and zinc sources from other foods.
Lentils are good if you're looking for a meat substitute. [Photo credit].
Take home messages
My recommendations are:
- Reduce your intake of processed meat. A ham sandwich every day is not a good idea. The occasional bacon sandwich is okay.
- Enjoy red meat in moderation. The current WHO guidelines state that you can have 750g raw (or 500g) cooked red meat per week. So three red meat meals a week is okay. Keep it lean and grass fed if possible.
- Serve up some vegetarian meals! Include some meat-free meals in your menu. Plant based proteins like beans and lentils are great for winter soups and stews.
- Keep the variety going. Choose other protein sources like chicken, turkey and fish. Be sure to opt for free-range poultry and also to include both white and oily fish.
Linia Patel is a leading dietitian and sports nutritionist. She's passionate about empowering people to better manage their health and optimise their performance through learning the essence of healthy eating. Outside of work, Linia is a wannabe triathlete. Visit her website: www.liniapatel.com.