A new study says the more red meat you eat, the greater your risk of death, and that substituting other types of protein lowers mortality risk.

The study, by researchers at Harvard School of Public Health, published online Monday in the Archives of Internal Medicine, involved 37,698 men from 1986 to 2008 and 83,644 women from 1980 to 2008 who were free of cardiovascular disease and cancer at the start. Participants regularly filled out questionnaires about their diets.

There were 23,926 deaths in the group – 5,910 from cardiovascular disease and 9,464 from cancer.

The study found that each daily serving of red meat was associated with a 12 percent increased risk of death, and that processed meats such as bacon were associated with a 20 percent increased risk of death – even after controlling for the fact that people who eat the most of these kinds of meat are typically less physically active, more likely to smoke and have a higher body mass index. 

Substituting one serving per day of other foods (including fish, poultry, nuts, legumes, low-fat dairy, and whole grains) for a daily serving of red meat was associated with a 7 percent to 19 percent lower mortality risk.

The conclusion in the study’s abstract states, “Red meat consumption is associated with an increased risk of total, CVD, and cancer mortality. Substitution of other healthy protein sources for red meat is associated with a lower mortality risk.”

The American Meat Institute, in a statement, criticized the study for using “notoriously unreliable self-reporting” about diet histories and “obtuse methods” to analyze the data.

Betsy Booren, AMI Foundation Director of Scientific Affairs, wrote, “Red and processed meat continues to be a healthy part of a balanced diet and nutrition decisions should be based on the total body of evidence, not on single studies that include weak and inconsistent evidence and stand in contrast to other research and to the Dietary Guidelines for Americans, 2010.” 

Booren said “all of these studies” about risks associated with red meat “struggle to disentangle other lifestyle and dietary habits from meat and processed meat and admit that they can’t do it well enough to use their conclusions to accurately recommend people change their dietary habits.” She said evidence has shown, and common sense suggests, that a balanced diet and a healthy body weight are the keys to good health.