WEDNESDAY, March 6 (HealthDay News) -- Grilled hot dogs and sausages may be tasty treats at ball games and picnics, but a new study of nearly 450,000 people finds that eating too much processed meat might shave years off your life.

Those who ate the most processed meat increased their risk of dying early by 44 percent. In broader terms, if people ate less processed meat, the number of premature deaths overall would drop by almost 3 percent, Swiss researchers reported.

"Our recommendation is to limit processed meat intake to less than an ounce a day," said study author Sabine Rohrmann, head of the division of cancer epidemiology and prevention at the Institute of Social and Preventive Medicine at the University of Zurich.

The researchers could only show an association between eating processed meat and an increased risk of dying early, and not a cause-and-effect link. There are, however, some reasons to believe the association may be real, the scientists said.

"We know of some potential mechanisms that probably all contribute," Rohrmann said. "Meat is rich in cholesterol and saturated fat, which may be the link with coronary heart disease."

Processed meat is also treated with nitrates to improve durability, color and taste. "However, it also causes the formation of carcinogens. These are linked to the risk of colorectal and stomach cancer," Rohrmann said.

In addition, high iron intake from meat may lead to an increased risk for cancer, she said.

Another expert noted that previous research supports the link between processed meat and health problems.

"A wide array of studies have linked meat intake to higher rates of chronic disease," said Dr. David Katz, director of the Yale University Prevention Research Center in New Haven, Conn.

Eating relatively more meat likely means eating fewer plant foods, which protect against chronic disease, he said.

"The case for us eating mostly plants is strong," Katz said. "But those inclined can eat meat without harming their health, provided they choose wisely and steer clear of bologna."

For the study, which was published online March 6 in the journal BMC Medicine, Rohrmann and an international team of investigators collected data on nearly 450,000 men and women. At the start of the study, none of the participants had had cancer, a heart attack or stroke. The researchers also collected data on diet, smoking, exercise and weight.

By the middle of 2009, more than 26,000 of those in the study had died.

"Mortality is increased when we compare those participants who eat more than 40 grams per day of processed meat to those who have 10 to 20 grams per day," Rohrmann said.

The higher the consumption, the higher the risk. "For the highest consumption group (those who consume at least 160 grams of processed meat per day) mortality was 44 percent higher compared with those who eat little meat (10 to 20 grams a day)," she said.

"Since meat is also rich in certain minerals and vitamins, we do not recommend not to eat meat anymore, but to reduce the intake of processed meats and to limit the intake of red meat to about 300 to 600 grams per week as recommended by other nutrition groups," Rohrmann said.

In addition, eating a lot of processed meat went along with other unhealthy choices. Those who ate the most processed meat ate the fewest fruits and vegetables and were more likely to smoke. Also, men who ate a lot of meat tended to drink a lot, the researchers found.

One expert pointed out that it might be hard to change bad habits in the United States.

"A side of sausage, a BLT or a ham sandwich are the daily norm for many Americans," said Samantha Heller, a clinical nutritionist at the NYU Center for Musculoskeletal Care, in New York City. "Limiting consumption of processed meat to less than an ounce a day, as the researchers of this study suggest, will be a difficult recommendation to put in place unless we can educate the public about the health concerns associated with eating processed meats regularly."

Health professionals, educators and food companies need to make efforts to change the culture of food in the United States so that healthy, plant-based eating becomes the daily norm, Heller said.

The American Meat Institute took issue with the findings.

"While we have significant concerns about the study's methodology and results, if one chooses to accept the study's conclusions Americans can rest assured that their processed meat consumption is, on average, at the approximate level recommended by these researchers and can feel confident that red meat consumed as part of healthy balanced diet offers good nutrition and no increased risk of mortality," American Meat Institute Foundation Chief Scientist Betsy Booren said in a statement.

More information

For more on a healthy diet, visit the U.S. Department of Agriculture.