We’ve all heard it hundreds of times — cut back on red meat to guard against heart disease. But a recent analysis of data from 20 studies involving a total of more than 1.2 million people from 10 different countries who were followed for up to 18 years suggests that this advice is too broad.

Surprisingly, researchers found that eating unprocessed beef, pork or lamb was not associated with increased risk for either heart disease or diabetes. However, eating even a moderate amount of processed meats (those preserved by smoking, curing, salting or adding chemical preservatives, such as nitrates) — such as bacon, salami, sausage, hot dogs, many deli meats and perhaps processed poultry — was another story. Average daily consumption of one 1.8-ounce (50-gram) serving of processed meat (about one to two slices of deli meat or one hot dog) was associated with a 42% increase in heart disease risk and a 19% increase in diabetes risk.

The saturated fat and cholesterol in meat typically are the focus of recommendations to cut back on red meat… yet researchers found that unprocessed and processed meats actually contained similar amounts of saturated fat and cholesterol. Where meat products differed: The processed meats contained about four times as much sodium and about 50% more nitrates (since nitrates also naturally occur in meat) than unprocessed red meat — which suggests that these ingredients may be the true culprits to avoid when it comes to guarding against heart disease and diabetes.