March 12, 2012 -- People who eat less red meat may live longer than people who regularly eat burgers, steaks, and processed foods like bacon, hot dogs, and sausage, a new study shows.
For the study, Harvard researchers delved into the diets of more than 120,000 men and women who are taking part in the long-running Health Professionals Follow-up Study and the Nurses’ Health Study.
Every four years, people in the study were asked detailed questions about their eating habits. They were also asked about other health determinants like smoking and drinking, exercise, and body weight.
Men were in their early 50s, on average, when the study started. Women were in their mid-40s.
During the next 20 years, researchers found that people who ate the most red meat were more likely to die, and die of cancer or heart disease, compared to people who reported eating the fewest daily servings of beef, pork, and lamb.
Researchers estimate that a single daily 3-ounce serving of unprocessed red meat, which is about the size of a deck of playing cards, raises the risk of dying of heart disease by about 18% and raises the risk of dying of cancer by 10%.
Processed meats appear to be even more hazardous. A single daily serving of processed meats like bacon (two slices), sausage, or hot dogs (1 piece), raised the risk of dying of heart disease by 21% and dying of cancer by 16%.
“Processed red meat is definitely more harmful than fresh or unprocessed red meat,” says researcher An Pan, PhD, a research fellow in the department of nutrition at the Harvard School of Public Health, in Boston.
Replacing red meat with leaner proteins like fish, chicken, nuts, low-fat dairy, whole grains, or beans may lower the risk of early death by 7% to 19%, the study shows.
“Substituting almost any other food for red meat reduces risk, sometimes substantially,” Marion Nestle, PhD, MPH, a professor of nutrition, food studies, and public health at New York University, says in an email.
“This is a call for a more varied diet that substitutes other foods for red meats, especially nuts,” says Nestle, who was not involved in the research.
Other experts agree.
“These lifestyle and diet changes really do make a difference,” says Dean Ornish, MD, founder and president of the nonprofit Preventive Medicine Research Institute in Sausalito, Calif. He is also clinical professor of medicine at the University of California, San Francisco.
“I think everybody would be better off if they consumed a plant-based diet. But even modest changes -- substituting chicken for beef, for example, or fish for chicken -- also play an important role in reducing risk,” says Ornish, who wrote a commentary on the study but was not involved in the research.
The study and commentary are published in the Archives of Internal Medicine.