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. 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. As an 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 diseases 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 various chronic diseases. Eating processed meat is associated with 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 cannot prove that the processed meat caused them. Even so, the evidence is convincing because the links are strong and consistent. Additionally, all of this is supported by studies in 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.
A new study finds that eating even small amounts of processed meat can increase the risk of heart disease and death. Researchers from McMaster University and Hamilton Health Sciences in Canada have found that eating as little as 6 ounces of processed meat per week could significantly increase the risk of heart disease and death. That’s the equivalent of eating just two sausages in a week.
“We found consumption of 150 grams [just over 5 ounces] or more of processed meat per week was associated with a 46 percent higher chance of cardiovascular disease and 51 percent higher chance of death compared with those who did not consume processed meat,” said co-author Mahshid Dehghan, PhD, investigator of global health at the David Braley Cardiac, Vascular, and Stroke Research Institute.
The new study was recently published in the American Journal of Clinical Nutrition. Dehghan and team analyzed the diets and health outcomes of 134,297 people from 21 countries. Researchers tracked their meat consumption and rates of cardiovascular disease. After following study participants for almost 10 years, the researchers found that eating 150 grams (just over 5 ounces) or more of processed meat a week was associated with an almost 50 percent increased risk of cardiovascular disease and more than 50 percent higher risk of death from all causes than those who ate no processed meat.
“The main limitation of this study was that we were unable to include method of cooking for each country,” Dehghan said. “We acknowledge that this limitation might attenuate the association between unprocessed red meat and poultry and health outcomes.”
Surprisingly, researchers discovered that eating moderate levels of unprocessed meat, like beef, pork or poultry had a neutral effect on health. “Observational studies can help determine links and associations but cannot determine causation,” said Lisa K. Diewald, MS, RD, LDN, program manager at the MacDonald Center for Obesity Prevention and Education at Villanova University College of Nursing.
She explained that an observational study that addresses diet and health risk, like this one, typically relies on food frequency questionnaires (FFQ), which may be prone to errors from participants either overestimating or underestimating their consumption. “However, the large sample size in this study is helpful in mitigating this risk,” Diewald said. “In addition to the large sample size, the study’s staff was well-trained staff in the use of the FFQ, so the results may be looked on as more reliable.”