Does eating red and processed meat cause cancer?

Does eating red and processed meat cause cancer?


Should we abandon the traditional idea of what a healthy diet is?

Historically, an important part of the Western diet has been food from animal flash, and meat consumption is still on the rise globally. However, there is accumulated evidence that regular consumption of animal proteins (over 10% of total calorie intake), can gravely impact our health.

A diet rich in animal proteins (meat, eggs, fish, milk, and milk products) and saturated fats, seems to be associated with a range of health issues, from overweight, obesity, and autoimmune disorders to cognitive impairment and cancer development.

On the other hand, a balanced diet consisting of plant-based, “whole food” that is, foods rich in fibers, vitamins, and minerals, is not only important for preventive health but is also the best way of chronic disease management.

Raising animals to slaughter them for food is deeply unsettling, immoral, and unhealthy, and it badly hurts our environment. Fertilizing land to produce grains and lentils also cause gas emissions, but gas-releasing of 1 kg of meat is about a hundred time higher.

Hopefully, these inconceivable actions will come to an end in the near future as young scientists are putting in much effort to create a vegan-friendly meat-alternative that is entirely plant-based. Another, perhaps more important question, is whether governments will put as much effort into setting up programs to encourage people to switch to healthier behaviors.

Humans need proteins, no question about that.

Every structure, tissue, and cell in our body are composed of proteins, that is, essential amino acids. Our body is unable to produce them itself (except some of them) and we need to get proteins from our diet. However, when we think of proteins, we habitually coupling it with animal proteins. What most people don’t realize is that plants are also a rich source of proteins, minerals (iron; zinc; copper; selenium), vitamins  (except vitamin B12). Most importantly, plant foods are cholesterol-free.

However, the public opinion supported by the food industry (as well as science supported by the industry), goes that animal-derived proteins (i.e., meat, dairy, eggs, fish) are of higher quality in comparison to those of non-animal origin (nuts, seeds, peas, and beans); meaning that the body absorbs animal proteins better than those from plant sources. Typically, the argument runs that they are more compatible with ours.

Guess whose proteins would be even more compatible with ours? Yep, right. Following that logic, who should we be hunting for food then… humans?


Harmful chemicals in meat: heme iron 

People mistakenly assume that only by eating meat can get a sufficient amount of iron. Or, they are simply ignorant of the fact that plant-based foods are also loaded with iron (green leafy vegetables contain more iron in 100 grams than the same portion of red meat!).

Iron is a critically important mineral for the proper functioning of our body and brain. Without enough iron, our body cannot produce enough hemoglobin, a molecule in red blood cells responsible for oxygen distribution. Inadequate amount of this mineral is one of the main causes of iron-deficiency anemia worldwide.

There are two types of iron from dietary sources: heme iron (in red meat, fish, poultry), and nonheme iron that comes from plants.

However, there is consistent evidence that heme iron plays a sinister role in the promotion of carcinogenic N-nitroso compounds. Adding nitrite (as a preservative) to processed meat also increases the toxic potential of heme iron in such products.

The compounds can also be produced by our stomach, preferably at lower pH (and a diet rich in animal proteins lowers pH significantly), and stimulate mucosal cell proliferation, which greatly influences the risk of digestive cancer.

Even more harmful chemicals are formed by cooking meat: high-temperature frying, broiling, grilling, and barbecuing produce heterocyclic amines and polycyclic aromatic hydrocarbons which are known carcinogens. After all, you may not succeed in killing all the germs, because some microbes are thermophilic, are very stable at high temperatures. This is especially the case with ready-made meals.

A large follow-up study, published in 2009, included more than half a million women and men in the US, who were screened and monitored over a period of 10 years. The study findings clearly showed an increased risk for colorectal cancer and mortality in participants who consumed large quantities of red meat.

Gut microbiota disturbance

Too often and too much meat and other animal proteins can ‘excite’ the gut microbiota composition with the potential to instigate long-term inflammation. Such events can activate pro-inflammatory cytokines (released by the immune system), that is, activate auto-immune response and, subsequently, cause auto-immune diseases in the host.

It has also been theorized that the increased amount of saturated fat and iron in red meat contributes to this pathogenesis, creating free radicals and thereby causing oxidative stress and inflammation.

Several experimental studies have shown that the interaction of sulfur from meat with gut microbiota plays an important role in the carcinogenesis of intestinal cells. Sulfur may induce the formation of toxic substances, such as hydrogen sulfide. This chemical compound can impair DNA, mucosa, and many other important structures.

On the other side, sulfur from meat inhibits methane-producing bacteria in our gut. Normally, these bacteria assist in neutralizing hydrogen in our intestines by binding it into methane, thus saving our mucosa.

Brain disorders

Because our gut produces important neurotransmitters necessary for proper brain functioning, recent research found that burdening such a sensitive environment with too much animal proteins can cause a variety of mental disorders, such as depression and anxiety, to name a few.

Furthermore, iron overload can cause hypoxia (deficiency in the amount of oxygen in the tissues and cells) that can lead to serious health complications.

Hormonal imbalance

A diet rich in animal proteins and fats causes a higher level of circulating estrogen and other hormones in the blood. It is well-established that long-time exposure to sex hormones, after the reproductive years, is one of the leading causes of postmenopausal breast cancer in women.

Hosting deadly viruses

Herald Zur Hausen, from German Cancer Research Centre and the 2008 Nobel Prize winner for discovery on links between HPV and cervical cancer, challenges existing literature on the correlation between meat and cancer initiation by pointing to a very interesting fact: there is a surprisingly low incidence of colon cancer in some countries where people eat relatively large quantities of red meat (such as Mongolia, Bolivia, and Botswana). In his opinion, livestock viruses and infectious agents circulating in mammals raised on huge meat-production farms, are responsible for tumor initiation and growth.

Particularly worrying is the finding of the polyomavirus, which is often found in mammal meat, including domestic animals, and is associated with prostatic carcinoma. Unfortunately, many of these viruses are very thermostable and cooking cannot destroy them.

New genetic testing in calves has identified an increased risk in the occurrence of disease with the presence of the CMAH gene. The gene encodes the synthesis of the sugar molecule Neu5Gc in mammals, and also in certain fish species. The human body cannot synthesize this molecule, and its ingestion into our body can cause numerous adverse reactions, including inflammation, autoimmune responses, and even cancer. The largest quantities of this sugar were found in caviar; the most expensive food in the world.

Due to the complexity of the topic, further research is needed to describe and confirm the exact mechanisms and its pathogenesis in humans.

Finally – genes, lifestyle, and disease

Most often, GENES need to be ACTIVATED or stimulated by some environmental factors, such as nutrition, for example, to express their good or bad side.

Studies of cancer in migrants found higher incidence and mortality rates of African Americans in comparison to native Africans, found that lifestyle and dietary changes are most likely to be causal factors. Namely, after migrating to the US, native Africans “westernized” their diet and began consuming more animal-based food and fat, unlike native Africans who tend to eat more plant-based foods rich in fiber.

And now, it’s personal

The reason why people prefer animal-based foods is that they are simply uninformed or misled (by the food industry) into thinking that only meat can ensure proper nutrients.

But, if the facts enumerated here failed to persuade you why cutting meat is the best route to a healthy and happy life, for the environment and for the planet – don’t worry. Just relax and leave your left hemisphere of the brain to …think again.

But, also, keep in mind that if you are somewhere in between, that is, neutral, it might buy you more time, but it does not resolve anything.

Anyway, we did not want to provoke you and make your blood broil by pilling up all this information.

We just don’t want you propping against the wall if, one day, the cost (that is often tragic), for the years of nasty habits, such as imbalanced eating and drinking, suddenly arrive.

Get a grip on yourself if you want to see good days!

So, tell me, what are you making for dinner tonight?


To save the planet, to save our health, and to save the animals, there is only one thing we can do. IF WE HAVE A CHOICE, AND MOST OF US DO HAVE, WE MUST STOP EATING MEAT ALTOGETHER! We strongly believe that the highest possible standards for animal welfare at industrial dairy farms should be introduced and mandatory both for producers and governments. Furthermore, the consumers should be made aware of animal maltreatment such as, for example, placing animals in cages so small that they cannot turn around, causing muscle atrophy, in order to make their meat softer for consumption. These pressing issues should be addressed urgently to directly impact consumer buying decisions; they should be encouraged to stop buying from suppliers who do not follow animal welfare assurance standards, in order to halt cruelty and other widespread malpractices across the globe. Not only is dairy farming cruel in most of its settings, but it has also the potential to badly damage the environment, increase global warming, impact soil acidification, and cause hyperthropication. The discharge of nitrates and fertilizers into the surface waters, sewage, and further into an aquatic system, cause excessive proliferation of algae and planktons (nitrates stimulate the growth of those organisms). This further leads to a reduction of oxygen in water, necessary for numerous organisms to survive. Additionally, exposure to organic dust, endotoxins, and gases can cause serious respiratory health disorders in farmers and workers. We strongly believe that consumers would pay a higher price for premium, organic dairy products coming from small dairy farmers, if only they were able to make more informed decisions. To reduce these environmental burdens, we should decrease production, financing, and the consumption of low-cost, unhealthy products obtained from abused and miserable animals at large industrial farms.

Tags: DigestibilityFactorsProteins