The researchers crunched the numbers from 20 previous studies done worldwide, and found that eating processed meat was linked to a 42% higher risk of heart disease. And it was tied to a 19% higher risk of type 2 diabetes.
They say the risk rose to that level with about 2 ounces of lunch meat or 1 hot dog a day.
The researchers say the processed meats include any meat preserved by smoking, curing, or salting, or with the addition of preservative chemicals. That includes bacon, sausage, salami, hot dogs, or processed deli or luncheon meats.
On the flip side, the Harvard team didn't find any higher risk of heart disease or diabetes among those eating unprocessed red meat. That included beef, pork, or lamb. The study did not include poultry.
The Harvard scientists say the high levels of sodium can raise blood pressure, and the nitrates in the preservatives have been linked in animal studies with atherosclerosis (hardening of the arteries), and with reduced glucose tolerance, which is a precursor to diabetes.
