Eating a portion of processed red meat daily can increase a person's risk of dying young by up to 20 per cent, says a long-running US study of more than 120,000 people.
While the research by Harvard University experts offers more evidence that eating red meat increases the risk of heart disease and cancer, it also counsels that substituting fish and poultry may lower early death risk.
"This study provides clear evidence that regular consumption of red meat, especially processed meat, contributes substantially to premature death," said Frank Hu, senior author of the study in the Archives of Internal Medicine.
Researchers gleaned their data from a study of 37,698 men who were followed for 22 years and 83,644 women who were tracked for 28 years.
Subjects answered surveys about their eating habits every four years.
Those who ate a card-deck-sized serving of unprocessed red meat each day on average saw a 13 per cent higher risk of dying than those who did not eat red meat as frequently.
And if the red meat was processed, like in a hot dog or two slices of bacon, that risk jumped to 20 per cent.
However, substituting nuts for red meat lowered total mortality risk by 19 per cent, while poultry or whole grains lowered the risk by 14 per cent and fish did so by seven per cent.
The authors said between seven and nine per cent of all deaths in the study "could be prevented if all the participants consumed fewer than 0.5 servings per day of total red meat".
Processed red meat has been shown to contain ingredients such as saturated fat, sodium, nitrites and some carcinogens that are linked to many chronic ailments including heart disease and cancer.
"More than 75 per cent of the $US2.6 trillion (NZ$3.2 trillion) in annual US health care costs are from chronic disease," said an accompanying commentary by Dean Ornish, a physician and dietary expert at the University of California, San Francisco.
"Eating less red meat is likely to reduce morbidity from these illnesses, thereby reducing health care costs."
Beef and Lamb NZ said Kiwis eat red meat within national and international guidelines.
"The methods used to try and predict risk of death from cancer and heart disease in this study are known to be inaccurate and unreliable," said Fiona Carruthers, the nutrition manager at the organisation.
"The researchers themselves acknowledge the limitations of how they measured the amount of specific foods eaten, including red meat.
"As well as the questionable assessment methods, this type of study can only show an association between red meat and health outcomes, not that one causes the other. There are a number of risk factors for cancer and heart disease; obesity remains the most prevalent. Singling out one food in a condition influenced by such a wide range of factors is misleading."
A separate study, also led by Hu but published in the American Heart Association journal Circulation, found that men who drank sugar-sweetened beverages daily faced a 20 per cent higher risk of heart disease than men who did not.
The study tracked more than 42,000 men, most of them Caucasian, over 22 years. It found higher heart risks, and higher levels of inflammation and harmful lipids known as triglycerides in daily sweet-drinkers.
The effects were not seen in men who drank as many as two sugar-sweetened beverages per week.
According to Hu, the research "provides strong justification for reducing sugary beverage consumption among patients, and more importantly, in the general population".
Heart disease is the biggest killer in the United States and top risk factors include obesity, smoking, lack of exercise, diabetes and poor eating habits.