Eating Meats and The Risk of Cancer

The World Health Organization (WHO) released a report this October linking processed meats and red med meats to an increased risk of certain cancers.

Is this a real threat? How much is too much? Should I avoid these meats altogether? These are questions and concerns that the majority of people including major news outlets have been trying to come to grips with.

Let’s everybody take a deep cleansing breathe! The answers to these questions seem to have been lost in the world-wind of misinformation and misunderstanding. The WHO is ultimately still unclear on the exact relationship between the consumption of these meats and developing cancer. To put all this in perspective here is what we need to know about the WHO’s report.

These findings came from the International Agency for Research on Cancer (IARC) an organization that researches the causes of human cancer and acts as an adviser to the WHO.

The IARC reviewed hundreds of studies and was able to conclude that the consumption of processed meats causes colorectal and stomach cancer. The consumption of red meat was also associated with colorectal,  pancreatic and prostate cancers.

“We’ve known for some time about the probable link between red meat and processed meat and colon cancer, it is now being backed by substantial evidence. This decision doesn’t mean you need to stop eating any red and processed meat. But if you eat lots of it you may want to think about cutting down. You could try having fish for your dinner rather than sausages, or choosing to have a bean salad for lunch over a BLT. ” (Professor Tim Key, Cancer Research UK’s epidemiologist at the University of Oxford)


What is Processed Meat?

Processed meat refers to meat that has been salted, cured, fermented, smoked or transformed through any other process to enhance flavor or improve preservation. Examples of processed meat include hot dogs, ham, sausages, pepperoni, bacon, turkey bacon, corned beef, beef jerky, salami, as well as any canned meat and meat-based preparations and sauces.

What is Red Meat?

Red meat is characterized as muscle meat including beef, veal, pork, lamb, mutton, horse and goat. Red meat is typically darker in color because of higher levels of protein, hemoglobin and myoglobin in blood and muscle.


What is The Risk?

The IARC classifies agents characterized as carcinogenic to humans into one of five groups:

Group 1: Carcinogenic to humans
Group 2A: Probably carcinogenic to humans
Group 2B: Possibly carcinogenic to humans
Group 3: Not classifiable
Group 4: Probably not carcinogenic

Although the report put processed meats into the Group 1 category along with substances like alcohol, asbestos and tobacco smoke it is important to understand that they do not all share the same level of risk hazard. The risk of smoking, for example, is quite greater than the risk associated with eating these meats.

Smoking is estimated to increase the risk of developing lung cancer by 25 times and causes a million deaths worldwide every year. Compare that to a person’s risk of colorectal cancer, which increases by a factor of about 1.1 or 1.2 for every 3.5 oz. serving of processed meat consumed per day which translates to about 34,000 deaths worldwide every year.

So why are processed meats in the same group as carcinogens like smoke? Because the IARC isn’t looking at risk, it’s looking at evidence. And they are saying that there is sufficient evidence to classify processed meats as a carcinogen. It’s akin to classifying someone as a criminal, but there being dramatically different degrees of how dangerous the criminal is.

As for red meat, the IARC classified it as “probably carcinogenic” to humans, placing it in Group 2A. This means that the evidence in humans is still somewhat limited, but there is sufficient evidence in experimental animals of the substance’s carcinogenic nature.

Researchers say that the risk of colorectal cancer increases by about 17% with each 3.5 oz. of red meat consumption.

What is The Link?

Researchers have found that processing meats can result in the formation of carcinogenic chemicals. The smoking process, for example, may lead to the formation of cancer-causing compounds called polycyclic aromatic hydrocarbons. Also, processing meat often involves using nitrogen-based preservatives to prevent bacterial growth and as coloring agents. Nitrates are particularly problematic, since the body converts them to nitrosamines, which are carcinogenic.

As for red meat, one theory revolves around heme iron. Plants contain only non-heme iron, while animal proteins have a mix of heme and non-heme iron. Beef contains the highest proportion of heme iron, with about 69% coming from the heme type. Pork is roughly 39% heme iron. A number of studies have shown that higher quantities of heme iron have been linked to an increased risk of colorectal cancer. Additional research has indicated that the process of digesting red meat could lead to the release of chemicals that produce genetic damage to colon cells in just a few weeks.

Cooking methods may also play a role. High-temperature methods, such as grilling, pan-frying, broiling or barbecuing, can form more cancer-causing compounds, such as heterocyclic amines, or polycyclic aromatic hydrocarbons, which are also found in air pollution.

Now What?

While the panel did not offer specific guidelines on processed meat or red meat consumption, its conclusions add support for individuals to monitor and limit their intake. Because even if the risk of developing colorectal cancer due to meat consumption may be relatively small, the risk does increase with the amount of meat consumed. This is particularly pressing since the global consumption of meat has nearly doubled in the past several decades.

To limit your intake, the USDA recommends substituting red meat and processed meat with seafood by increasing seafood consumption to eight ounces per week. Plant-based proteins offer a healthy alternative. Plant-based foods have substantially more antioxidants, fiber and minerals than animal-based foods and significantly less cholesterol and saturated fat. Plant-based foods also tend to be alkaline-forming, which can help your body combat inflammation, reduce stress and protect bone health.