Last October, the World Health Organization (WHO) released a two-page report entitled Carcinogenicity of Consumption of Red and Processed Meat, warning the planet that processed meat definitely causes colorectal cancer in humans, and that red meat “probably” causes colorectal cancer in humans. The report listed a total of 20 scientific references. WHO’s frightening anti-meat proclamation made headlines worldwide and had a major impact on how people think about meat and health. While plenty of pro-meat critiques of the WHO report have been published, the majority of those I read took the WHO’s findings at face value and emphasized that the statistical risk associated with eating processed and red meat is very small.
I strongly disagree. I read the report and all of the experimental studies cited in the report. I found no scientific evidence to support the WHO’s anti-meat cries, and I think it is important to set the record straight.
Let me disclose my biases from the start (something WHO committee members should also be required to do). Eight years ago I changed from a low-fat, low-cholesterol, low-carbohydrate, high-fiber/high-plant diet to a mostly-meat diet, loaded with fat and cholesterol and quite low in fiber, and it reversed every health problem I ever had (read my story on the About page). Naturally I was worried that my new meaty menu was going to kill me, so I began digging into the science for myself and lo and behold: there was no evidence that meat increases risk for heart disease, obesity, or diabetes after all. I came to believe, based on my powerful personal experience and my reading of the research, that animal foods (meat, poultry, and seafood), complete with their natural cholesterol and fats, are good for people.
But what about cancer? Is my meat-based diet, which is working so well for me right now, putting me at risk for cancer down the road?
I am a scientifically curious psychiatrist. I love getting to the bottom of things, and my life’s work centers around helping people confront reality, no matter how complicated or unwelcome it can sometimes be. If the truth is that meat makes me feel great now but is ultimately going to do me in, I want and need to know that. Whether you eat meat only occasionally, every day, or are an all-meat zero-carber, you need to know it too, so I dove into the WHO report to see what’s what.
What I discovered was that THE WHO REPORT IS NOT A SCIENTIFIC DOCUMENT. IT IS A POLITICAL DOCUMENT. Politicians can get away with making sweeping statements to the general public that stand on shaky ground. Scientists are held to a higher standard. They are supposed to show their work, and defend their positions as objectively and honestly as humanly possible. After reading the studies upon which the WHO’s anti-meat proclamations are made, I concluded that there simply is no scientific evidence that meat causes cancer in humans.
And I am not alone.
“…the interactions between meat, gut and health outcomes such as CRC [colorectal cancer] are very complex and are not clearly pointing in one direction….Epidemiological and mechanistic data on associations between red and processed meat intake and CRC are inconsistent and underlying mechanisms are unclear…Better biomarkers of meat intake and of cancer occurrence and updated food composition databases are required for future studies.” To read the full report: [open access]
Translation: we don’t know if meat causes colorectal cancer. Now THAT is a responsible, honest, scientific conclusion.
How the WHO?
How could the WHO have come to such a different conclusion than this recent international gathering of cancer scientists? As you will see for yourself in my analysis below, the WHO made the following irresponsible decisions:
2.The WHO relied heavily on dozens of “epidemiological” studies (which by their very nature are incapable of demonstrating a cause and effect relationship between meat and cancer) to support its claim that meat causes cancer.
3. The WHO cited a mere SIX experimental studies suggesting a possible link between meat and colorectal cancer, four of which were conducted by the same research group.
4. THREE of the six experimental studies were conducted solely on RATS. Rats are not humans and may not be physiologically adapted to high-meat diets. All rats were injected with powerful carcinogenic chemicals prior to being fed meat. Yes, you read that correctly.
5. Only THREE of the six experimental studies were human studies. All were conducted with a very small number of subjects and were seriously flawed in more than one important way. Examples of flaws include using unreliable or outdated biomarkers and/or failing to include proper controls.
6. Some of the theories put forth by the WHO about how red/processed meat might cause cancer are controversial or have already been disproved. These theories were discredited within the texts of the very same studies cited to support the WHO’s anti-meat conclusions, again suggesting that the WHO committee members either didn’t read these studies or deliberately omitted information that didn’t support the WHO’s anti-meat position.