Red Meat and Processed Meat - IARC Monographs on the Evaluation of Carcinogenic Risks to Humans Volume 114
Incidence of cancer mortality in function of diet animal content.
Cancer risk across mammals | Nature
Cancer is a ubiquitous disease of metazoans, predicted to disproportionately affect larger, long-lived organisms owing to their greater number of cell divisions, and thus increased probability of somatic mutations1,2. While elevated cancer risk with larger body size and/or longevity has been documented within species3,4,5, Peto’s paradox indicates the apparent lack of such an association among taxa6. Yet, unequivocal empirical evidence for Peto’s paradox is lacking, stemming from the difficulty of estimating cancer risk in non-model species. Here we build and analyse a database on cancer-related mortality using data on adult zoo mammals (110,148 individuals, 191 species) and map age-controlled cancer mortality to the mammalian tree of life. We demonstrate the universality and high frequency of oncogenic phenomena in mammals and reveal substantial differences in cancer mortality across major mammalian orders. We show that the phylogenetic distribution of cancer mortality is associated with diet, with carnivorous mammals (especially mammal-consuming ones) facing the highest cancer-related mortality. Moreover, we provide unequivocal evidence for the body size and longevity components of Peto’s paradox by showing that cancer mortality risk is largely independent of both body mass and adult life expectancy across species. These results highlight the key role of life-history evolution in shaping cancer resistance and provide major advancements in the quest for natural anticancer defences.
Discovery and Features of an Alkylating Signature in Colorectal Cancer
Abstract
Several risk factors have been established for colorectal cancer, yet their direct mutagenic effects in patients' tumors remain to be elucidated. Here, we leveraged whole-exome sequencing data from 900 colorectal cancer cases that had occurred in three U.S.-wide prospective studies with extensive dietary and lifestyle information. We found an alkylating signature that was previously undescribed in colorectal cancer and then showed the existence of a similar mutational process in normal colonic crypts. This alkylating signature is associated with high intakes of processed and unprocessed red meat prior to diagnosis. In addition, this signature was more abundant in the distal colorectum, predicted to target cancer driver mutations KRAS p.G12D, KRAS p.G13D, and PIK3CA p.E545K, and associated with poor survival. Together, these results link for the first time a colorectal mutational signature to a component of diet and further implicate the role of red meat in colorectal cancer initiation and progression.
Significance:
Colorectal cancer has several lifestyle risk factors, but the underlying mutations for most have not been observed directly in tumors. Analysis of 900 colorectal cancers with whole-exome sequencing and epidemiologic annotations revealed an alkylating mutational signature that was associated with red meat consumption and distal tumor location, as well as predicted to target KRAS p.G12D/p.G13D.
Healthiness of the carnivore regime?
There were a few points mentioned by @[email protected] about the negative aspect of carnivore diets on health: https://lemmy.world/comment/14453309
Here are some sources on why the carnivore diet is completely unhealthy:
While there is debate in the scientific community over just how much meat belongs in a human diet, it is impossible for all or even most humans to eat primarily meat. Beef production at the scale required to feed billions of humans even at current levels of consumption is environmentally unsustainable. It is not even healthy from a theoretical evolutionary viewpoint, the microbiome expert Gilbert explained to me. Carnivores need to eat meat or else they die; humans do not. “The carnivore gastrointestinal tract is completely different from the human gastrointestinal tract, which is made up of a system designed to consume large quantities of complex fibers.”
Christopher Gardner, a professor of medicine at Stanford University, is less convinced by the evidence.
“Are these T rex? African lions? Or humans? Assuming [you are referring to] humans, this sounds disastrous on multiple levels,” he said.
The lack of dietary fibre in an all-meat diet is likely to wreak havoc on the bacteria in our colons, known as the microbiome, he said. “Growing evidence suggests that in the absence of adequate fibre, the bacteria in the colon consume and thin the protective mucus lining, which then leads to impaired immune function and inflammation.”
Eating more meat also contributes to a rise in a substance called trimethylamine N-oxide in the blood which, according to research by the Cleveland Heart Lab, may be as bad for heart disease as saturated fat and elevated cholesterol.
Factory farming of animals is also linked to antibiotic resistance in humans and is a huge contributor to the greenhouse gases that contribute to global warming.
“In summary, I think a ‘carnivore diet’ is inappropriate for human health, bad for the health of our planet, abusive of the human labour force that handles the preparation of meat, abusive of animal rights and welfare,” he said.
By skipping fruits and vegetables, people likely won’t get enough fiber in their diets, which can affect gut health. They also will miss out on carotenoids and polyphenols, substances with antioxidant properties that have been linked to lower risk of chronic diseases such as Type 2 diabetes and some types of cancer. Animal products also contain high amounts of saturated fat and cholesterol.
In addition to the potentially adverse health effects of the diet, Willett, professor of epidemiology and nutrition, noted that industrial production of animal-based foods is harmful to the planet. “There’s also the issue of justice that basically the Global North—Europe [and] the United States—cause most of the problems with climate change that we have today, and this sort of perpetuates that.”