Jump to content

Should I stop eating bacon based upon the media reports that it causes cancer?

Recommended Posts

With the recent marketing announcement that Finnebrogue Artisan Foods have launched their new Nitrite/Nitrate free cure the press have once again have been guided towards the 2015 World Health Organisation (WHO) and IARC (International Agency for Research on Cancer) working group report on the "Carcinogenicity of the consumption of red meat and processed meat". It is reported that  Finnebrogue have invested ~£14m in the development of their new fruit based cure and this is the first time they have launched a commercial bacon product, and so it is not unexpected that they will be wanting to highlight information that could help in the promotion of their new product. Unfortunately, once the media sense a story it can often lead to a misrepresentation of the facts that can confuse and mislead the public.

The recent emphasis in the press has been on the perceived dangers of developing cancer as a result of eating bacon that has been processed using Nitrite and Nitrate based upon the WHO report. Whilst I like to keep an open mind based upon latest research, especially when it comes to food safety, I do like to try to ensure that information/evidence is considered in the correct context and that relevant conclusions are being reached and sensationalism avoided. With this in mind I have tried below to cut through some of the hype that has appeared recently in the media.

The WHO and IARC do a lot of very important research and present their conclusions to allow individual governments to define their own local safety policies. The WHO/IARC working group (consisting of 22 people from different countries) choose to do this review based on epidemiological studies suggesting that small increases in the risk of several cancers may be associated with high consumption of red meat or processed meat. Although these risks are small, they could be important for public health because many people worldwide eat meat and meat consumption is increasing in low- and middle-income countries.

The base research was not carried out directly by the working group however they were reviewing the data from 800 separate studies carried out by others from all over the world to try to establish whether they showed any link between the consumption of red meat and processed meat with the development of cancer in humans. Of the 800 studies the information in only 15 were deemed of sufficient granularity and quality for looking at the possible effects of eating Red meat and only 18 studies for Processed meat. These studies though were of sufficient size samples that they felt that statistical conclusions could be drawn from their results. The conclusions drawn by the members of the working group were not unanimous and were reached as a majority decision - which suggests that the results themselves were not necessarily compelling. The exact size of the majority was not specified so it could have been as large as 21:1 or as little as 12:10.

Of the 15 studies reviewed for Red meat, 7 reported a positive association of colorectal cancer with high vs low consumption.
Of the 18 studies reviewed for Processed meat, 12 reported a positive association of colorectal cancer with consumption.
It is not clear from the report whether the subsequent conclusions were drawn from all of the studies or only from those that showed positive associations.
The report also says that there is inadequate evidence in experimental animals for the carcinogenicity of consumption of red meat and of processed meat.

Whilst the media have understandably used this report to selectively focus on bacon, the report itself does not actually mention bacon at all. It only refers generically to Processed Meat, which is defined in an associated WHO Q&A paper as "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… …Examples of processed meat include hot dogs (frankfurters), ham, sausages, corned beef, and biltong or beef jerky as well as canned meat and meat-based preparations and sauces". It is therefore not known how big an impact eating bacon specifically has within any of these studies.

The conclusions drawn from the studies do not differentiate between the different types of cure used in the Processed meats or the amount of any cure present. In some of the countries in which these studies where carried out (e.g. Japan) it would be more usual to cure their foods using only salt and not use Nitrate or Nitrite at all.

The amount of cure in the meat is actually quite difficult to assess as the "ingoing" cure levels that we calculate when starting to cure and the resulting "residual" cure levels in the food that we eat are very different. Whilst ingoing Nitrite is now at a maximum of 150 mg/Kg in the US and EU it is relatively unstable and is broken down quite quickly by heat, enzyme and bacterial action. The amount of Nitrite taken up will also vary on the meat being cured. The residual levels of Nitrite in the meat after curing will be significantly lower than the ingoing levels and subsequent cooking will reduce these levels even further. The average levels of residual nitrite in cured meat products are in the range 10–40 mg/kg with values in the U.S. being in the lower part of the range.
The report Q&A paper states that "Cooking at high temperatures or with the food in direct contact with a flame or a hot surface, as in barbecuing or pan-frying, produces more of certain types of potentially carcinogenic chemicals. However, there were not enough data for the IARC Working Group to reach a conclusion about whether the way meat is cooked affects the risk of cancer".

The report also concludes that the potential risk of developing colorectal cancer increases by 18% with every 50 g of Processed meat that you consume daily, however it does not explain what that 18% refers to. Quoting statistical increases is always open to misinterpretation - especially by the media - as it can appear to make results more significant than they actually are. An example of this would be that an increase likelihood from, say, 1 in 1million to 2 in 1million (a pretty insignificant increase in most cases) but when described as a % increase it would actually be expressed as a 100% increase.

Another reason for the media to over interpret the results is that Processed meat was recently classified by the IARC as carcinogenic to humans (Group 1) - in the same category as tobacco smoking and asbestos. They are clear to explain though that this does not mean that consumption of processed meat is as carcinogenic as tobacco smoking and asbestos. The IARC classifications describe only the strength of the scientific evidence about an agent being a cause of cancer, rather than assessing the comparative level of risk at specific exposure levels.

To try to put the risk of cancer from Processed meat into a comparative perspective: There are approximately 7.4 billion people in the world today and according to the most recent estimates by the Global Burden of Disease Project, there are about 34,000 cancer deaths per year worldwide that are attributable to diets that are high in processed meat. These numbers contrast with about 1 million cancer deaths per year globally due to tobacco smoking, 600,000 per year due to alcohol consumption, and more than 200,000 per year due to air pollution.

Subsequent to the publishing of the 2015 report the Chairman of the EFSA's (European Food Safety Authority) Panel on Food Additives and Nutrient Sources Added to Food said: “We re-assessed the safety of nitrites and nitrates added to food…  and concluded that there was no need to change previously set safe levels for either".

So, based upon this report should you avoid eating bacon?

You have to be comfortable with the food that you are eating and so it is a personal choice as to whether you stop based upon the small perceived increased risk of developing colorectal cancer. If this is your decision then remember that the report refers to the eating of ALL processed meat - and not just bacon.


References used:

Carcinogenicity of consumption of red and processed meat
Q&A on the carcinogenicity of the consumption of red meat and processed meat
IARC Monographs evaluate consumption of red meat and processed meat
Nitrite and nitrosyl compounds in food preservation
Nitrites and nitrates added to food

  • Thanks 3
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...