Excuse the meat puns…
Skipping to number 6 this week (see number 1: Breast cancer), quite topically it featured heavily in the news due to a study by the World Health Organisation (WHO) “Processed meat ranks alongside smoking as major cause of cancer”. Queue hysteria…..
- Breast cancer
- Gastric cancer
- Malignant melanoma (melanoma)
- Non-small-cell lung cancer (NSCLC)
- Ovarian cancer
- Colorectal cancer
The various melodramatic titles came:
- Processed meat ranks alongside smoking as major cause of cancer, World Health Organisation says. The Daily Telegraph, October 26 2015
- Just two rashers of bacon a day raises your risk of cancer: Health chiefs put processed meat at same level as cigarettes. Daily Mail, October 27 2015
- Processed meats rank alongside smoking as cancer causes – WHO. The Guardian, October 26 2015
- Meat and tobacco: the difference between risk and strength of evidence. The Guardian, October 26 2015
- Processed meats do cause cancer – WHO. BBC News, October 26 2015
- Red meat is ‘probably’ a carcinogenic experts warn as processed meat officially listed as cancer risk. Daily Mirror, October 26 2015
- Drop the bacon roll – processed meats including sausages ‘as bad for you as SMOKING’. Daily Express, October 23 2015
Why does this make me angry?
Given the statistics around CRC and in view of the large number of people who consume processed meat, it is perhaps not surprising that the report from the WHO’s International Agency for Research on Cancer (IARC) classifying processed meat as carcinogenic to humans caused quiet a stir. This being said, the titles such as ‘sausages are as bad for you as smoking’ are just not true and actually can be more harmful than good. Previous examples of science exploding in the news such as the MMR-injections-linked-to autism titles actually caused mothers to withdraw their children from vital inoculations….
Are you what you eat?
In a previous post, I explored the potential of your genes determining who you are, and this new research raises a new (but yet very old!) question: are you what you eat? Looking back, the link between a high consumption of red meat and the risk of developing cancer is not recent news. Already in 2011 the UK’s Department of Health asked to an independent scientific advisory committee on nutrition (SACN) to issue a report on this matter. SACN expert found the association to be so strong that they recommended individuals who eats at least 90g of red meat per day to cut down to 70g daily to lower their risk.
You can increase your risk of cancer by 18%
Okay, a shocking statistic, but before you go off and chuck all your sausages in the bin, let’s really look at this in more detail. Quantifying the estimates from the study you can see that it is indeed true and that consuming more than 350 grams of processed meat per week means that increasing your risk by 18%. However, and a big however (!) this 18% is representative of a chance to develop colorectal cancer increasing from 56 in 1000 to 66 in 1000. Trying to put this into perspective, it’s like comparing the interest rates of two banks when you £10 to deposit…. a new bank (let’s say HSBC) may be offering 20% interest whilst your current bank (Barclays (?)) offers 3%, and of course you’re going to choose HSBC in this case. However, yearly gains are going to be so negligible that the interest rates are just not worth your time bothering with the inevitable call centres and frustration with people pretending their names are ‘Bob’ when you know they really live in India. I would say this is the same in the case of processed meat – this study similarly not weighing up the pros of eating processed meat (okay, it’s not the best meat in the world, but there is some nutritional value!)
If you are interested in reading up on what is carcinogenic, since the 1970s, the agency has reviewed more than 900 products, substances and exposures. More than 400 have been identified as ‘carcinogenic’, ‘probably carcinogenic’, or ‘possibly carcinogenic’ and is listed here.
So let’s all give up meat?
It may not be a bad idea in the western world going on what our diets generally tend to be. But let’s not be quick to forget than we can attribute at least a proportion of our evolved intelligence from eating meat, the theory is generally widely accepted with eating meat leading to: smaller stomachs/intestines and an overall larger brain due to the increase protein intake and less time foraging. We probably all need to work towards eating a healthier diet in some form or another, and this story highlights that.
The answer: A balanced diet – duh!
After the International Agency for Research on Cancer released the report, the assistant director-general of the World Health Organisation, Oleg Chestnov, announced that some foods needed to be limited as part of a healthy diet but did not need to be eliminated: He said the document linking red meats to cancer was aimed mainly at politicians, so that they can regulate the sector appropriately within their borders. Most governments throughout the world promote balanced approaches to diets based on scientific evidence. They encourage moderate consumption of foods from all the food groups. Of course!
Linking it back to Colorectal Cancer
So what is this colorectal cancer ’caused by sausages’?
Cancers are among the leading causes of morbidity and mortality worldwide, with about 14 million new cases and 8.2 million cancer related deaths in 2012. Colorectal cancer in particular is the 4th most common cancer accounting for nearly 14% of cancer – a total of 483,300 cases in 2015 were diagnosed. In comparison to the 30,000 or so deaths ‘linked to processed meat’, nearly one million cancer deaths per year are attributed to tobacco smoking while 600,000 cancer deaths each year are as a result of alcohol consumption. Another 200,000 cancer deaths a year are as a result of air pollution.
However there is hope. Patients that display aberrant epidermal growth factor receptor (EGFR) activation and are negative for KRAS mutation could benefit from antibodies therapy, (cetuximab or panitumumab) targeting EGFR. Luckily this is reported to be up to 40% of all patients tested. However it is still unclear what how other genes affect potential therapies: studies suggest that in wt KRAS patients who have BRAF mutations, the efficacy of anti-EGFR treatments is significantly reduced,with BRAF serving as a prognostic indicator whilst KRAS/EGFR acting as predictive.
Cancer is a terrible disease, however, advancements in ‘personalized medicine’ have greatly improved the outcomes that you can now expect. Next week’s post will focus on a cancer which doesn’t get the news it deserves: gastric.