Scientists have been debating the link between red and processed meat. and certain forms of cancer. Reports warn that red meat lovers may have a greater likelihood of developing certain cancers of the throat and stomach, while a recent perspective paper in Meat Science refutes this theory, and cautions about uncertainties in the scientific evidence.

A study in the American Journal of Gastroenterology followed nearly 500,000 older US adults and found that the risks of cancer were relatively greater among those who ate a large amount of red meat. Study participants in the top 20 percent for red-meat intake were 79 percent more likely than those in the bottom 20 percent to develop esophageal squamous cell carcinoma, a cancer that arises in the lining of the upper part of the esophagus.

In light of this report and others like it, little new nutritional recommendation has evolved to advise people on how to limit their intake of red and processed meats.

Furthermore, a recent perspective paper, authored by 23 scientists and coordinated by the Norwegian University of Life Sciences, underlines the uncertainties in the scientific evidence and suggests that further research is 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.

These studies show that 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. The scientists argue that in these studies the animals are only given red meat and that their diet doesn't contain any ingredients that can protect and help the gut stay healthy such as vegetables, fiber, 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 23 researchers state that although red and processed meats may still present a serious public health impact, 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 scientists conclude that efforts to make meat healthier in general need to continue, however it is a complex issue and science does not yet have a full understanding of how food that we eat affects our stomach and our health.