Swapping one portion of red meat for fish or nuts daily could cut the risk of early death by almost a fifth, research in the British Medical Journal suggests.
Scientists said the Harvard study showed the benefits of the “Med diet” - with eggs, nuts and fish more often chosen instead of meats.
The eight year study examined the dietary habits of more than 81,000 people in the US.
People were asked how much they had eaten of different types of foods including red and processed meats - such as ham, hot dogs and bacon - as well as nuts, fish, eggs, whole grains, legumes and chicken and turkey.
The results showed that swapping a daily portion of meat for fish cut the risk by 17 per cent over the eight-year period.
And those who increased their consumption of nuts, while cutting back on red and processed meats, saw a 19 per cent reduced risk of dying over the time.
Switching meat for whole grains cut risk by 12 per cent while opting for skinless poultry or vegetables was linked to a 10 per cent lower risk, while choosing eggs was linked to an eight per cent lower risk of early death.
The study also found that those who increased consumption of red and processed meat over the period by half a portion had a 10 per cent higher risk of dying in the subsequent eight-year period.
The increased risk for processed meat alone was 13 per cent and was 9 per cent for unprocessed red meat. One rasher of bacon counted as half a serving of processed meat, while half a serving of red meat was equivalent to one and half slices of roast beef.
Previous studies have shown that red and processed meat is linked to an increased risk of Type 2 diabetes, heart disease and bowel cancer.
The researchers, based in the US and China, concluded: "This association with mortality was observed with increased consumption of processed and unprocessed meat, but was stronger for processed meat.
"A decrease in total red meat consumption and a simultaneous increase in the consumption of nuts, fish, poultry without skin, dairy, eggs, whole grains, or vegetables over eight years was associated with a lower risk of death in the subsequent eight years.
"These findings suggest that a change in protein source or eating healthy plant based foods such as vegetables or whole grains can improve longevity."
Dr Giota Mitrou, director of research at the World Cancer Research Fund, said: "This new study reinforces our own evidence that eating red meat or processed meat increases the risk of cancer.
"We know that the choices people make are a result of the environments that they live in, so we call on the Government to take a bold step and introduce policies, such as subsidies on healthier food like fruit and vegetables, that empower people to make these healthier swaps by making our daily environments healthier.
"We recommend that people eat no more than three portions of red meat a week, as this provides a balance between the advantages of red meat as a source of essential nutrients and the disadvantages.
"However, we recommend that people eat little or no processed meat, such as bacon.”
Dr Ian Johnson, Nutrition researcher and Emeritus Fellow, Quadram Institute Bioscience, said: “The important new point is that adults seem to be able to significantly improve their chances of a longer healthier life by adjusting their diets toward what can be broadly described as a more ‘Mediterranean’ pattern.”