Processed meat is generally considered unhealthy.
Numerous studies have linked it with diseases like cancer and heart disease.
No doubt processed meat contains many harmful chemicals that are not present in fresh meat.
This article takes a detailed look at the health effects of processed meat.
What is processed meat?
Processed meat is meat that has been preserved by curing, salting, smoking, drying, or canning.
Food products categorized as processed meat include:
- Sausages, hot dogs, salami.
- Ham, cured bacon.
- Salted and cured meat, corned beef.
- Smoked meat.
- Dried meat, beef jerky.
- Canned meat.
On the other hand, meat that has been frozen or undergone mechanical processing like cutting and slicing is still considered unprocessed.
Summary: All meat that has been smoked, salted, cured, dried, or canned is considered processed. This includes sausages, hot dogs, salami, ham, and cured bacon.
Eating processed meat is associated with an unhealthy lifestyle
Processed meat has consistently been linked with harmful effects on health.
This is a fact that health-conscious people have been aware of for decades.
For this reason, eating high amounts of processed meat is more common among people with unhealthy lifestyle habits.
For example, smoking is more common among those who eat lots of processed meat. Their intake of fruit and vegetables is also much lower.
It is possible that the links found between processed meat and disease are partly because people who eat processed meat tend to do other things that are not associated with good health.
Most observational studies on processed meat and health outcomes try to correct these factors.
Nevertheless, studies consistently find strong links between processed meat consumption and chronic diseases.
Summary: People who are not health-conscious tend to eat more processed meat. This may partly explain some associations in studies investigating processed meat consumption and disease.
Processed meat is linked with chronic disease
Eating processed meat is associated with an increased risk of many chronic diseases.
These include:
- High blood pressure (hypertension).
- Heart disease.
- Chronic obstructive pulmonary disease (COPD).
- Bowel and stomach cancer.
Studies on processed meat consumption in humans are all observational in nature.
They show that people who eat processed meat are more likely to get these diseases, but they can not prove that processed meat causes them.
The evidence is convincing because the links are solid and consistent.
Additionally, all of this is supported by studies on animals. For example, studies in rats show that eating processed meat raises the risk of bowel cancer.
One thing is clear; processed meat contains harmful chemical compounds that may increase the risk of chronic disease. The most widely studied compounds are discussed here below.
Summary: Eating high amounts of processed meat over a long period may increase the risk of many chronic diseases, such as heart disease and cancer.
Nitrite, N-nitroso compounds and nitrosamines
N-nitroso compounds are cancer-causing substances believed to be responsible for some of the adverse effects of processed meat consumption.
They are formed from nitrite (sodium nitrite) that is added to processed meat products.
Sodium nitrite is used as an additive for 3 reasons:
- To preserve the red/pink color of meat.
- To improve the flavor by suppressing fat oxidation (rancidification).
- To prevent the growth of bacteria, improve flavor, and cut the risk of food poisoning.
Nitrite and related compounds, such as nitrate, are also found in other foods. For example, some vegetables find nitrate in relatively high levels and may even be beneficial for health.
However, not all nitrite is the same. Nitrite in processed meat can turn into harmful N-nitroso compounds, the most widely studied of which are nitrosamines.
Suggested read: Meat: Good or bad?
Processed meat is the primary dietary source of nitrosamines. Other sources include contaminated drinking water, tobacco smoke, and salted and pickled foods.
Nitrosamines are mainly formed when processed meat products are exposed to high heat (above 266°F or 130°C), such as when frying bacon or grilling sausages.
Animal studies indicate that nitrosamines may play a significant role in forming bowel cancer.
This is supported by human observational studies, indicating that nitrosamines may increase the risk of stomach and bowel cancer.
Summary: Processed meat that is fried or grilled may contain relatively high levels of nitrosamines. Studies suggest that these compounds may increase cancer risk in the stomach and bowel.
Polycyclic aromatic hydrocarbons (PAHs)
Meat smoking is one of the oldest preservation methods, often used with salting or drying.
It leads to the formation of various potentially harmful substances. These include polycyclic aromatic hydrocarbons (PAHs).
PAHs are a large class of substances that form when organic matter burns.
They are transferred into the air with smoke and accumulate on the surface of smoked meat products and meat that is barbecued, grilled, or roasted over an open fire.
They can be formed from the following:
- Burning wood or charcoal.
- Dripping fat that burns on a hot surface.
- Burnt or charred meat.
For this reason, smoked meat products can be high in PAHs.
It is believed that PAHs may contribute to some of the adverse health effects of processed meat.
Numerous studies in animals have shown that some PAHs can cause cancer.
Summary: Smoked meat products may contain high amounts of polycyclic aromatic hydrocarbons (PAHs). These compounds have been shown to cause cancer in animals.
Heterocyclic amines (HCAs)
Heterocyclic amines (HCAs) are a class of chemical compounds that form when meat or fish is cooked under high temperatures, such as frying or grilling.
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They are not restricted to processed meat, but significant amounts can be found in sausages, fried bacon, and meat burgers.
HCAs cause cancer when given to animals in high amounts. Generally, these amounts are much higher than those typically in the human diet.
Nevertheless, numerous human observational studies indicate that eating well-done meat may increase the risk of colon, breast, and prostate cancer.
The level of HCAs can be minimized by using gentle cooking methods, such as frying under low heat and steaming. Avoid eating charred, blackened meat.
Summary: Some processed meat products may contain heterocyclic amines (HCAs), carcinogenic compounds also found in well-done meat and fish.
Sodium chloride
Processed meat products are usually high in sodium chloride, also known as table salt.
Salt has been added to food products for thousands of years as a preservative. However, it is most often used to improve the taste.
Although processed meat is far from being the only food that is high in salt, it may contribute significantly to the salt intake of many people.
Excessive salt consumption may play a role in hypertension and heart disease, especially in those with a salt-sensitive hypertension condition.
In addition, several observational studies indicate that diets high in salt may increase the risk of stomach cancer.
This is supported by studies showing that a high-salt diet may increase the growth of Helicobacter pylori. This bacterium causes stomach ulcers, an essential risk factor for stomach cancer.
Adding salt to whole foods to improve the flavor is fine, but eating massive amounts of processed foods may cause harm.
Summary: Processed meat products contain large amounts of salt, which may contribute to some health problems.
Summary
Processed meat contains various chemical compounds that are not present in fresh meat. Many of these compounds are harmful to health.
Suggested read: Are nitrates and nitrites in foods harmful?
For this reason, eating a lot of processed meat products for a long period (years or decades) may increase the risk of chronic disease, especially cancer.
However, eating them occasionally is fine. Just make sure not to let them dominate your diet and avoid eating them daily.
At the end of the day, you should limit your intake of processed foods and base your diet on fresh whole foods.
