New study linking red meat and cancer will be harder to prove in humans
Published:  06 January, 2015

New research has apparently uncovered a link between red meat consumption and the formation of cancerous tumours.

The study, conducted on mice by the University of California in San Diego, reportedly showed a link between the sugar molecule Neu5Gc, found in high quantities in red meat, and the formation of cancerous tumours.

The researchers used mice, as they mimic humans in that they do not produce their own Neu5Gc, producing antibodies to fight it. The study found that, when mice ingested Neu5Gc, they developed “systemic inflammation” and increased tumour formation with Neu5Gc accumulated in these tumours.

The researchers had previously discovered that animal Neu5Gc can be absorbed into human tissues. However, in this study, they hypothesised that eating red meat could lead to inflammation if the body’s immune system was constantly generating antibodies against the foreign molecule, Neu5Gc. Chronic inflammation is known to promote tumour formation, the research team reported.

“Until now, all of our evidence linking Neu5Gc to cancer was circumstantial or indirectly predicted from somewhat artificial experimental set-ups,” said research leader Ajit Varki, MD, professor of medicine and cellular and molecular medicine.

“This is the first time we have directly shown that mimicking the exact situation in humans — feeding non-human Neu5Gc and inducing anti-Neu5Gc antibodies — increases spontaneous cancers in mice,” Varki added.

Commenting on previous studies, which claimed to show a link between red meat consumption and cancer, Dr Emma Derbyshire from the Meat Advisory Panel (MAP) said: “The causes of cancer are complex, involving a combination of both our genes and lifestyles. While it is important to recognise that there are proven ways to minimise cancer – such as being more active, drinking less alcohol, giving up smoking and maintaining a healthy weight – it is more difficult to pinpoint the role of specific dietary factors.  

“For example, dietary methods used in studies to assess meat intakes can be limited, often leading to inaccurate estimates of meat intakes and failing to separate out processed and lean meats.

“Consequently, this can lead to bold statements, such as the need to avoid eating red meat. This is concerning given that red meat is a valuable source of essential vitamins and minerals.”

Varki’s team admitted the link between Neu5Gc and tumour formation would be harder to prove in humans. He concluded: “Of course, moderate amounts of red meat can be a source of good nutrition for young people. We hope that our work will eventually lead the way to practical solutions for this catch-22.”