By Edwina Green, Corporate Nutritionist

April is bowel (colorectal) cancer awareness month.  Red meat consumption has long been associated with this disease, but in October 2015 World Health Organisation “concluded that each 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by 18%. [1]”  This statement was based on research by the International Agency for Research on Cancer (IARC) and published in the Lancet Oncology and resulted in the WHO classifying processed meat and red meat as carcinogenic and probably carcinogenic to humans respectively. 

There is no doubt that bowel cancer is a serious disease; with incidences rising since the 1970’s. According to Cancer Research UK bowel cancer is the fourth most common cancer in the UK [2]. Lifestyle factors such as the consumption of red and processed meat (21%), overweight and obesity (13%), alcohol (12%), smoking (8%) and ionising radiation (2%) are associated with increased risk of bowel cancer [2]. What does this mean in practical terms; should we completely remove red and processed meats from our diet if we wish to avoid bowel cancer?

A closer look at the research

While the IARC assessed the data from 800 epidemiological studies; their findings are largely based on 14 prospective cohort studies in the general population, with supporting evidence from 6 case controlled studies. Prospective cohort studies are epidemiological studies which follow a group of similar individuals (cohorts) over a period of time who differ with respect to certain factors under study, to determine how these factors affect rates of a certain outcome. For example, a cohort of male office workers who vary in terms of red and processed meat consumption, to test the hypothesis that the 10-year incidence rate of bowel cancer will be highest among high consumers, followed by moderate consumers, and then non consumers. The key benefit of these types of studies is that they highlight possible associations between different factors which can then inform future research, for example case control studies to provide stronger evidence that one factor plays a role in certain outcome.

Prospective cohort studies have to establish a baseline through tests and questionnaires, these are then repeated during the study timeframe. The trouble is that questionnaires are limited; if I asked you to recall what you ate during the last 24 hours, how accurate would your recall be? Would you be able to tell me the quantity of beef you had eaten?, whether it was grass or grain-fed?, was it cooked from scratch or a ready meal placed in the microwave?, if you had a walk after your meal? Capturing all the variables and potential influencers is a big task.

So where does this leave us in respect of the consumption of processed and red meat?   As with many things nutrition based, consider your own personal situation and employ moderation. Here is the framework I consider with my clients

1. Is there a familial risk?

Do you have a family history of bowel cancer? If the answer is yes, then you have reason to be cautious, modifying all risk factors not just processed and red meat consumption is advisable. Incorporating fibre and exercise into your life can also be beneficial in reducing the risk of developing bowel cancer.

2. Moderate consumption of processed and red meat in your diet.

Processed and red meat can be valuable sources of protein, vitamins and minerals, and so has a place in a balanced and varied diet. I encourage all my clients to eat a wide variety of food, with protein available from red meat, poultry, fish and eggs through to nuts, seeds, beans and pulses. If you consume a wide variety of food you will not be eating processed or red meat daily and therefore your consumption is likely to fall below the parameters indicated by the various studies: less than 50g of processed meat daily [1] and 70g of red meat daily [3].

3. Consider quality not simply quantity:

The nature of the prospective study means that quality is much more difficult to define and there is a world of difference between a tinned frankfurter and an artisan cured salami. After all, salting, curing, fermentation, and smoking are all traditional methods of preserving meat, typically they take time and passion from the producer. Manufacturing processes are the antithesis of this and often add undesirable chemicals, colourings and sugar to enable mass production as well as prolonging shelf life. One of Michael Pollan’s Food Rules helps here; if you grandmother wouldn’t recognise the ingredient or you cannot pronounce it; don’t eat it.

4. Develop a relationship with your local butcher or find a box scheme.

Understand how your meat (regardless of colour or processing) has been raised. A recent review and meta-analysis of 67 studies published by the University of Newcastle found that grass-fed and organic meats have a better profile of fatty acids than conventionally raised meats [4], further studies are required to see if this finding can be applied to other nutrients. Nevertheless, this is one area where paying more, but eating less could have health benefits for us and the environment.

5. How you cook your meat has an impact.

Cooking meat at high temperatures by pan frying, barbequing or grilling produces higher levels of heterocyclic amines (HCA).
These have been identified as carcinogens and studies are linking HCA produced by cooking method and bowel cancer [5]. Slow cooking using an indirect heat source, for example braising, stewing or poaching will reduce the level of HCAs produced and by association the risk of a number of cancers, not just bowel cancer.

Research by Macmillian estimates more than 700,000 of the 2 million people currently living with cancer are of working age [6], which means that businesses need to consider how cancer can impact their employees. At Superwellness, we help employees and employers understand the modifiable risk factors for cancer and give practical nutritional advice on cancer prevention. Please contact us if you’d like to look at ways to support your employees in this area.

Edwina Green, Associate and Registered Nutritional Therapist

Edwina is a firm believer in natural health and the transformative benefits that good nutrition can bring. Before making the career move to naturopathic nutrition, she ran her own company working in the City of London. She is fully aware of the challenges of trying to follow a healthy diet and lifestyle, while juggling full time work and ensuring quality time with family and friends.  She is passionate about helping people take practical steps to manage their own health and teaching them to dissect the varied and often conflicting information that we receive via the media.

[1] Bouvard V, Loomis D, Guyton KZ, Grosse Y, Ghissassi FE, Benbrahim-Tallaa L, Guha N, Mattock H, Straif K; International Agency for Research on Cancer Monograph Working Group. (2015). Carcinogenicity of consumption of red and processed meat. Lancet Oncology. 16 (16), 1599-600.

[2] Cancer Research UK. (2016). Bowel Cancer Research. Available: http://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/bowel-cancer. Last accessed 4th April 2016.

[3] NHS Choices. (2016). Red meat and the risk of bowel cancer. Available: http://www.nhs.uk/Livewell/Goodfood/Pages/red-meat.aspx. Last accessed 4th April 2016.

[4] Średnicka-Tober D, Barański M1, Seal C, Sanderson R, Benbrook C, Steinshamn H, Gromadzka-Ostrowska J, Rembiałkowska E, Skwarło-Sońta K, Eyre M, Cozzi G, Krogh Larsen M, Jordon T, Niggli U, Sakowski T, Calder PC, Burdge GC, Sotiraki S, Stefanakis A, Yolcu H, Stergiadis S, Chatzidimitriou E, Butler G, Stewart G, Leifert C. (2016). Composition differences between organic and conventional meat: a systematic literature review and meta-analysis. The British Journal of Nutrition. 115 (6), p 994-1011.

[5] Amit D Joshi, Andre Kim, Juan Pablo Lewinger, Cornelia M Ulrich, John D Potter, Michelle Cotterchio, Loic Le Marchand, and Mariana C Stern. (2015). Meat intake, cooking methods, dietary carcinogens, and colorectal cancer risk: findings from the Colorectal Cancer Family Registry. Cancer Medicine. 4 (6), 936–952.

[6] Macmillian Cancer Support. (2016). Managing Cancer in the Workplace. Available: http://www.macmillan.org.uk/information-and-support/organising/work-and-cancer/if-youre-an-employer/managing-cancer-in-the-workplace.html. Last accessed 4th April 2016.