It is often tough to calculate the effect of eating meat on health because of the confounding effect lifestyle has on health.
Generally, vegetarians have healthier lifestyles than the rest of the population. They are more likely to be physically active, less overweight, and less likely to smoke. As vegetarians do not eat any kind of meat, including processed meat, their data will influence statistics on non-processed meat consumers.
It is only possible to view the outcomes of eating meat and processed meat in an extremely large study where these variables can be separated from other lifestyle choices, which the authors achieved in the current study.
Historically, processed meat, especially red meats - sausage, bacon, deli meats, and hot dogs - have been linked to a significantly higher risk of developing type 2 diabetes and heart disease.
Past research has also revealed that processed meat consumption has been linked to a higher risk of pancreatic cancer, as well an elevated risk of colorectal cancer.
Scientists working on this European-wide study have suggested that processed meats such as bacon, ham, burgers, meat pies and sausages could be responsible for one in thirty premature deaths.
Generally, a diet high in processed meat was associated with other unhealthy choices. Participants who consumed the least amount of fruits and vegetables were more likely to smoke. Males who had a diet high in meat were also more likely to drink alcohol.
The amount of processed meat consumed impacts on overall mortalityThe authors reported that increased risk of all cause mortality (premature death) rose with the amount of processed meat people consumed.
Although residual confounding cannot be ignored, this finding still holds, even after correcting for confounding variables.
A small amount of red meat was found to be advantageous due to its significant source of vitamins and nutrients. However, a high intake was associated with increased mortality, even when lifestyle factors were taken into account.
Prof Sabine Rohrmann, from the University of Zurich, and lead author of this study explained:
"Risks of dying earlier from cancer and cardiovascular disease also increased with the amount of processed meat eaten. Overall, we estimate that 3% of premature deaths each year could be prevented if people ate less than 20g processed meat per day."
The authors estimated that if people decreased their daily processed meat intake to under 20 grams - for example a matchbook-sized portion - per day, close to 3 percent of premature deaths in a year could be avoided.
They believe the implication of this study is moderation. For instance, processed meat should be a small side dish instead of the main piece of a meal. Processed meat in moderation, and of course, always eat your vegetables.
In an Abstract in the same journal, the authors concluded "The results of our analysis support a moderate positive association between processed meat consumption and mortality in particular due to cardiovascular diseases, but also cancer."
In a previous study carried out by scientists from the National Cancer Institute in Rockville, Maryland, it was found that people who ate the most red and processed meats had a greater overall risk of dying prematurely, especially from cancer and heart disease, compared to non-meat eaters and those who ate very little. They added that those who ate more white meat had a slightly lower risk of overall and cancer death. Their study was published in Archives of Internal Medicine (March 2009 issue).
Written by Kelly Fitzgerald