Lead author An Pan, a research fellow, senior author Frank Hu, a professor of nutrition, both of the Harvard School of Public Health in Boston and colleagues observed 37,698 men from the Health Professionals Follow-up Study for up to 22 years and 83,644 women in the Nurses' Health Study for up to 28 years. The subjects wee free of cardiovascular disease and cancer at the beginning of the study. Study participants completed questionnaires on food consumption every four years.
"This study provides clear evidence that regular consumption of red meat, especially processed meat, contributes substantially to premature death," said Hu and Pan said in a statement.
The study published in the Archives of Internal Medicine found a combined 23,926 deaths were documented in the two studies, of which 5,910 were from cardiovascular disease and 9,464 from cancer.
One daily serving of unprocessed red meat -- about the size of a deck of cards -- was associated with a 13 percent increased risk of mortality, and one daily serving of processed red meat -- one hot dog or two slices of bacon -- was associated with a 20 percent increased risk.
However, replacing a serving of red meat with fish reduced the mortality risk by 7 percent, 14 percent for poultry, 19 percent for nuts, 10 percent for legumes, 10 percent for low-fat dairy products and 14 percent for whole grains.