Cancer is a sore, both for humans and animals. A study on the risk of developing the disease in mammals, conducted by French, Hungarian, American and Danish scientists, links this risk to the diet: carnivorous mammals are the most exposed.
To carry out this study, the team of scientists examined 110,148 animals of 191 different species since 2010. All of them died in zoos and their data was collected by the international non-profit organization, Species360, which collects and collects this information from around the world.
Orsolya Vincze, researcher at the Center for Ecological Research in Hungary and author of the article, specifies that the investigation focused on animals in captivity in zoos because it is difficult to collect this type of information on them. species in the wild. By choosing to do so, the scientists knew when the animals died and what the causes of death were.
The aggravating factor of diet
With the exception of blackbuck (a kind of antelope) and Patagonian maras (a type of rodent), all mammals studied were at risk of cancer. The results indicate that carnivores are particularly more susceptible to the disease. More than a quarter of cloudy leopards, bat-eared foxes and red wolves have died of cancer.
Carnivores have a microbiome different from other types of animals: it has fewer microorganisms which turns out to be a problem since a great diversity of microorganisms can help limit cancer. Diet is therefore a major factor in the risk of cancer. « We show that the phylogenetic distribution of cancer mortality is associated with diet, with carnivorous mammals (especially those that consume mammals) facing the highest cancer-related mortality. », write the scientists. The raw meat they eat can also carry viruses such as bovine leukemia. However, Orsolya Vincze specifies that more research needs to be done on the subject.
The results of the study also indicate that some resistance to cancer developed in the larger animals. This phenomenon is called the Peto paradox. According to Orsolya Vincze, the species developed ways to fight cancer in their genetic past. The team wants to focus on the mechanisms behind this genetic defense in order to develop ways to fight the disease in humans and animals.