© Catherine Karnow/Corbis Budapest, Hungary --- Typical Hungarian sausages, hams, bacon, meats at Nagy Vasarcsarnok, the Central Market. --- Image by Â© Catherine Karnow/Corbis

Many studies have suggested that eating red meat can be harmful to your health — increasing the risk of death from cancer or heart disease — yet new research published this week in the journal Circulation suggests that the negative health effects may be limited to processed meats.

Researchers at the Harvard School of Public Health sifted through more than 1,600 studies, ultimately identifying 20 that investigated the link between meat consumption and disease risk in more than 1.2 million people. They found that, while eating processed meats such as cold cuts, sausage and bacon was associated with a 42% higher risk of heart disease, they didn’t identify any increased risk from eating unprocessed beef, pork or lamb.

Study authors say that this is the first major analysis of international data examining the impact of both processed and unprocessed meat consumption — and distinguishing between the impact of the two — on risk for both heart disease and diabetes. According to the analysis, individuals who regularly consumed processed meats had a 19% higher risk for developing type 2 diabetes on average, but again, researchers noted no elevated risk for the condition among those who ate unprocessed red meats.

The team of researchers, led by epidemiologist Renata Micha, defined processed meat as any lamb, beef or pork (but not chicken) that had been treated or preserved by smoking, salting or addition of other chemicals. They found that, people who consumed an average of 1.8 ounce (50 gram) serving of processed meat each day — the amount of meat in a hot dog or a couple slices of deli meat — faced 42% higher risk for developing heart disease and a 19% higher risk for type 2 diabetes.

The amount of saturated fat and cholesterol in processed meats is comparable to that in unprocessed meats, the researchers say, but the amount of preservatives — and sodium in particular — is significantly higher for processed meats. While previous studies have linked red meat consumption to increased risk for cardiovascular disease and certain types of cancer, authors of this new study point out that previous research has not distinguished between processed and unprocessed meats.

Based on these findings, the researchers argue that Americans should be encouraged to eat less processed meat — specifically trying to limit consumption to one serving or less per week.

These findings may add momentum to national salt reduction initiatives — including efforts by the U.S. Food and Drug Administration to devise a strategy for limiting salt content in food products. The findings may also prompt further research into the health effects of certain preservatives: this past January, an initial inquiry by the European Food Safety Authority suggested that chemicals used to “add smokey flavor” may pose health risks, for example.

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