Meat and cancer risk

About meat

Meat is the flesh or any other edible portion of an animal that is consumed as food, including not just the muscles and fat, but also the tendons and ligaments . Meat can be broadly classified into the following categories:

  • Red Meat: Red meat refers to all livestock. Beef, pork, goat, and lamb are all examples.
  • Poultry: Also known as white meat, poultry comprises chicken and turkey.
  • Seafood: It comprises fish, crustaceans such as crab and lobster, and mollusks such as clams, oysters, scallops, and mussels.

Processed meat: Processed meat is meat that has been altered through salting, curing, fermenting, smoking, or other methods to maximize flavor or shelf life. The majority of processed meats comprise pork or beef, although they may also contain other red meats or poultry. Hot dogs (frankfurters), ham, sausages, corned beef, biltong or beef jerky, canned meat, and meat-based dishes and condiments are all examples of processed meat. Processed meat contains fewer essential elements and is higher in salt and fat than unprocessed meat. The association between processed meat and risk of cancer is clearly established. Processed meat has been identified as a carcinogen by experts. This means that it is now proven to cause cancer.

Meat, like other things, becomes unhealthy when consumed in large quantities. Red meat and processed meat have been proven to be particularly dangerous in terms of heart disease and cancer, although animal protein has many benefits when consumed in small amounts. Its principal benefit is, of course, protein, as well as vital amino acid and collagen reserves.

Red meat and processed meat are considered to be the most harmful type of meats that are linked to an increased risk of several types of cancer.

Assorted delicious grilled meat with vegetable over the coals on a barbecue

As of the most recent reports from the Global Burden of Disease Project, an independent academic research organization, processed meat diets cause around 34 000 cancer deaths globally each year. If the identified relationships between red meat and cancer are shown to be causal, the Global Burden of Disease Project estimates that red meat-rich diets may be accountable for 50 000 cancer deaths globally each year.

Processed meat is classified as group 1 carcinogen by IARC

When there is adequate proof of carcinogenicity in humans, this category is chosen. To put it another way, there is compelling evidence that the agent causes cancer. The assessment is mainly based on epidemiological studies that reveal the development of cancer in people who have been exposed to the substance. In the case of processed meat, this classification is based on epidemiological research that shows that consuming processed meat causes colorectal cancer.

The International Agency for Research on Cancer (IARC) working Group determined that consuming processed meats causes colorectal cancer. A link to stomach cancer was also discovered, but the evidence is inconsistent.

According to researchers, the risk increased with the amount of meat ingested. A review of data from eleven trials concluded that eating 50 grams of processed beef each day raises the risk of colorectal cancer by roughly 18%. Every 25g of processed meat consumed each day, about equivalent to a rasher of bacon or a slice of ham, increases the risk of cancer.

Red meat is categorized as group 2A carcinogen by IARC

Red meat is categorized as category 2A, which means it is probably carcinogenic to humans. In the instance of red meat, the classification is based on limited epidemiological evidence suggesting a link between consuming red meat and acquiring colorectal cancer, as well as considerable mechanistic evidence.

The clearest, but still limited, evidence for a link between red meat consumption and cancer is for colorectal cancer. There is additional evidence of relationships with pancreatic and prostate cancer as well.

The cancer risk associated with consuming red meat is more difficult to evaluate because the evidence that red meat causes cancer is weaker. However, if the link between red meat and colorectal cancer is confirmed to be causative, data from the same research suggest that the risk of colorectal cancer might rise by 17% for every 100 gram piece of red meat consumed daily.

How does processed meat and red meat promote cancer?

Compounds (present in meat, added during processing, or generated while cooking) can raise the risk of cancer by causing cell damage. Among these compounds are:

  1. Haem: This is a natural red pigment present in red meat and processed red meat. It has the potential to injure cells and cause bacteria in the body to create toxic substances. This can raise the risk of developing cancer.
  2. Nitrates and nitrites are two types of nitrates: These compounds are used to keep processed meat fresh for a longer period of time. Nitrites, when consumed, can be transformed into cancer-causing substances (N-nitroso compounds or NOCs). These compounds may be the reason why processed meats are more likely to cause cancer than fresh red meat.
  3. Polycyclic amines (PCAs) and heterocyclic amines (HCAs): When meat is subjected to high temperatures, such as grilling, or barbecuing, several carcinogenic compounds are generated. They have the potential to cause colon cell damage.

Red meat and colon cancer

Although the statistics differ, studies that have been conducted all around the world imply that a high meat consumption is associated with an elevated risk of colon cancer. Fresh meat seems to be guilty in some studies; processed, cured, or salted meat seems to be responsible in others — but in all cases, the concern is limited to red meat, not chicken. A  European study followed 478,000 men and women who were cancer-free at the start of the research. During the approximately five-year study period, 1,329 patients were diagnosed with colon cancer. People who consumed the most red meat (approximately 5 ounces or more per day) were around one-third more likely to get colon cancer than those who ate the least red meat (less than an ounce a day on average).

A survey sponsored by the American Cancer Society in the United States provided critical knowledge about the effects of long-term meat consumption. There were 148,610 participants between the ages of 50 and 74 who participated in the study. When the research started in 1982, all participants mentioned their dietary patterns and health practices, and then again 10 to 11 years later. Consumption of red and processed meats was associated with a significant increase in the risk of cancer in the lower colon and rectum at both times.

Some researchers have also indicated a moderate to high link between red meat diet and prostate cancer risk. Two studies offer some insights.  One study found that eating a lot of red meat, especially processed meat, doubled the risk of prostate cancer in African American men but not in white men. Another study discovered that properly processed meat appears to raise cancer risk by 40%. As a result, for both the prostate and the colon, it may be advisable to limit red meat consumption, particularly processed, grilled, and barbecued meats. Red meat has also been related to stomach cancer, bladder cancer, and breast cancer in other studies as well.

How to consume less red and processed meat?

  1. Instead of red meat, consume tofu, lentils, nuts, poultry, fish, or eggs. 
  2. Reduce your intake of red meat and fill at least half of your dinner plate with a variety of colorful veggies. 
  3. Increase the amount of vegetables and legumes in your recipes, such as including carrot, celery, mushrooms, peas, chickpeas, and lentils in gravies and curries. 
  4. Try a vegetable-based spaghetti, risotto, frittata, soup, or curry. 
  5. Include fish or chicken in curries, casseroles, pastas, salads, and sandwiches. 
  6. Swap processed meats like ham, bacon, prosciutto, or pepperoni with chicken, canned tuna, mushrooms, eggplant, tomato, capsicum, baked beans, or cheese.
  7. Instead of pepperoni or bacon, use chicken or vegetable toppings for your pizza.
  8. Prefer vegan meats. Use soy chorizo in burritos or seitan in stir-fries, for instance. Add vegetables as they give colour, texture, and essential micronutrients.
  9. Instead of processed breakfast meats like bacon or sausage, try eggs and yogurt. 
  10.  Prefer beans and lentils as they add texture, flavor and protein to soups and stews.


In conclusion, red and processed meat consumption appeared to be associated with a higher risk of colon and rectal cancer, as well as other cancers but with limited evidence. Current dietary standards encourage choosing lean, low-fat, or fat-free meats, implying that red meat as well as processed meat should be consumed in minimal amounts. 

Consuming more plant foods has been shown to reduce your chance of developing a variety of chronic diseases, including type 2 diabetes, high blood pressure, heart disease, as well as cancer. A plant-based diet can also help you maintain a healthy weight since it reduces saturated fats from meat. Cutting down on meat can help you reduce your risk of cancer. A plant-based diet, also known as vegetarian diet, is recommended by the American Institute for Cancer Research. Plant-based foods should make up at least two-thirds of your plate. This is because of the presence of phytochemicals in plant-based diets, which are nutrients required by your immune system to combat diseases such as cancer. Plant-based diets also contain more fiber, which have been proven to help reduce your risk of cancer. Fiber not only keeps you fuller for longer, but it also lowers your cholesterol, stabilizes your blood sugar levels, and helps you manage your bowels. Meat simply does not do that.