Researchers have discovered that eating red meat - any at all - appears to dramatically increase the risk of heart disease and cancer.
The Harvard University team followed the health of 37,698 men and 83,644 women - all disease-free at the start - over a period of up to 28 years.
During this period, there were 23,926 deaths: 5,910 from cardio-vascular disease and 9,464 from cancer. And, say the researchers, there was a strong link with the amount of red meat consumed.
A single daily serving, about the size of a deck of cards, appeared to raise the risk of death by 13 percent; a daily serving of processed meat, such as a single hot dog or two slices of bacon, upped the risk of death by 20 percent.
Every extra daily serving increases the risk by the same amount.
"We found that a higher intake of red meat was associated with a significantly elevated risk of total, CVD and cancer mortality, and this association was observed for unprocessed and processed red meat, with a relatively greater risk for processed red meat," say the authors.
"Substitution of fish, poultry, nuts, legumes, low-fat dairy products and whole grains for red meat was associated with a significantly lower risk of mortality."
The greater danger is of heart disease. The risk of this rose by 16 percent fo each extra serving of red meat - 21 percent, in the case of the processed stuff. The cancer risk was increased by 10 percent for red meat, and 16 percent for processed.
The authors estimate that 9.3 percent of deaths in men during follow-up and 7.6 percent in women could have been prevented if all the participants had consumed less than half a serving per day of red meat.
"This study provides clear evidence that regular consumption of red meat, especially processed meat, contributes substantially to premature death," says professor of nutrition and epidemiology Frank Hu.
"On the other hand, choosing more healthful sources of protein in place of red meat can confer significant health benefits by reducing chronic disease morbidity and mortality."