Recent reports warn about a link between eating red and processed meat and the risk of developing cancer in the gut. These reports have resulted in new nutritional recommendations that advise people to limit their intake of red and processed meats. A recent perspective paper, authored by 23 scientists, published in the latest issue of journal Meat Science underlines the uncertainties in the scientific evidence and points to further research needed to resolve these issues and improve the foundation for future recommendations on the intake of red meat.
The review discusses recent studies on associations between red and processed meat intake and cancer risk in humans and animals. In animals it is possible to promote cancer by giving the animals a chemical cancer challenge and a basic "standard" diet that is high in meat, but doesn't contain any ingredients that protect and can help the gut stay healthy. This means no vegetables, no fiber, no milk or other sources of calcium. In other words, the "standard" diet of the lab animals is not very comparable to that of humans. The many differences between diets for humans and laboratory animals may explain why the results seem to differ: in humans, the observed association between red and processed meat intake and cancer is relatively small in magnitude, but consistent, and may still present a serious public health impact. The 23 researchers conclude that other foods, in cooperation with the bacteria that live in the gut, may protect the gut so any potential adverse effects of meat may become less pronounced or may even be fully prevented.
The team of scientists further concludes that science does not yet have a full understanding of how food that we eat affects our gut and our health. To get a better grip on this complex issue, it is necessary that improved measures of how much meat people eat, the composition of the meat they eat, and how this affects the risk that cancer develops. At the same time, efforts to make meat healthier in general need to continue.
The paper is the result of an international workshop held in Oslo, Norway in November 2013, "How can we approach consensus on the healthiness of red meat?". The international team of researchers was coordinated by the Norwegian University of Life Sciences, in connection with the international research program 'The Ecology of Food Perception' at the Centre for Advanced Study at the Norwegian Academy of Science and Letters in Oslo.