November 4th, the Health Council of the Netherlands presented the new guidelines for healthy nutrition. These new guidelines came out a week after media headlines summarized the WHO results on red and processed meat as: ‘According to the World Health Organization, sausages are as carcinogenic as asbestos, plutonium and alcohol’, ‘Bacon causes cancer just as smoking does’ or ‘Meat on the blacklist of carcinogenic products.’
Should I panic? I guess it is time to evaluate my eating habits.
But maybe we should start by evaluating the headlines first. What do the media warnings on meat consumption actually tell us? Is meat really that dangerous?
Let’s check the facts.
The International Agency of Research into Cancer (IARC), which is part of the WHO, has analyzed a large number of scientific studies and concluded that red meat probably is carcinogenic in humans (group 2A) and that processed meat is carcinogenic in humans (group 1). These groups – 1 and 2A – reflect the level of evidence. They do not reflect how dangerous meat is with regard to cancer. The WHO conclusions mean that there is evidence that processed meat is carcinogenic, and that the link between red meat and cancer is less clear. In other words, meat is not necessarily as carcinogenic as asbestos or smoking. The evidence (for processed meat) is just as strong.
So what did the WHO state about the effect of meat on cancer? In their report, the WHO concluded that each 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by 18%. This sounds pretty terrifying, but one should consider that this is a relative risk. The risk of developing colorectal cancer is 18% higher compared to the risk when not consuming processed meat. Let’s say this initial risk is 10%, then your risk of colorectal cancer when you eat processed meat will be 11.8%. No conclusions were drawn about the effect of red meat, because of the weak evidence.
Let’s get back to the headlines: There is a risk. Indeed. But the evidence is only strong for processed meat and still, the risk of developing lung cancer from smoking is much higher. The knowledge that red and processed meat is associated with adverse effects on health is not new. Previous studies have shown this and even guidelines have addressed the consumption of meat before. Not only in relation to cancer, but also in relation to cardiovascular disease (or even with regard to sustainability and the environment). In the Netherlands it was recommended to eat less meat even before the WHO results were published.
So what do the new guidelines for healthy nutrition say about meat?
The 2015 guidelines specifically address red and processed meat consumption by stating that we should limit our consumption of red and processed meat and that we should eat more according to a plant-based dietary pattern than an animal-based dietary pattern.
But this is not really new, is it? We have been told over the years to eat more vegetables, to vary between different sources of protein and to limit animal fat. And actually – since I was evaluating my eating habits – I already did this.
So what is new about in the new guidelines?
These guidelines differ from the earlier ones by focusing on food groups rather than nutrients. Not only does this match scientific developments better, it also matches people’s daily choices with regard to diet. This is a good thing, this might make it easier for people to make the right choices. But still, knowing how to eat healthily does not necessarily mean that we eat healthily.
Unfortunately, that is true for me as well. Although I know exactly how to eat healthily, I sometimes need a reminder.
For me the new guidelines are a reminder to eat healthily, just as the meat headlines and infographics like the Schijf van Vijf of the Dutch Nutritional Center or the practical Healthy Eating Plate that was introduced by the Harvard School of Public Health.
A reminder with some new insights: we should eat more legumes, drink tea, replace unfiltered coffee by filtered coffee, eat unsalted nuts, drink less fruit juices and preferable no alcohol (or maximum one glass per day).
I can do that, I guess. It is not that different from how I am basically eating now. But please remind me every now and then!
Richtlijnen Goede Voeding 2015 – Gezondheidsraad
Véronique Bouvarda, Dana Loomisa, Kathryn Z Guytona, Yann Grossea, Fatiha El Ghissassia, Lamia Benbrahim-Tallaaa, Neela Guhaa, Heidi Mattocka, Kurt Straifa (on behalf of the International Agency for Research on Cancer Monograph Working Group). Carcinogenicity of consumption of red and processed meat. The Lancet Oncology, 2015. October.
Chan DSM, Lau R, Aune D, Vieira R, Greenwood DC, Kampman E, et al. (2011) Red and Processed Meat and Colorectal Cancer Incidence: Meta-Analysis of Prospective Studies. PLoS ONE 6(6): e20456. doi:10.1371/journal.pone.0020456