Researchers examined data pooled from 13 previously published studies that had a total of more than 1.4 million participants without heart disease, including more than 32,000 people who later went on to develop ischemic heart disease. Compared with people with the lowest daily red meat consumption — up to 25 g (0.9 oz) — people with the highest daily red meat intake — 25 to 141 g (5 oz) — were 12 percent more likely to develop ischemic heart disease. Similarly, people with the highest daily processed meat consumption — up to 10 g (0.4 oz) – were 11 percent more likely to develop ischemic heart disease than people with the lowest daily processed meat consumption — 9 to 78 g (2.8 oz). However, there wasn’t a significant difference in the risk of ischemic heart disease based on how much poultry people ate each day. There also wasn’t a meaningful increase in the risk of ischemic heart disease with each additional 50 g a day of poultry intake. “Reducing red and processed meats will lower the risk of ischemic heart disease,” says Rod Jackson, MBChB, PhD, a professor of epidemiology at the University of Auckland in New Zealand, who wasn’t involved in the study. Poultry doesn’t have the same risk because it doesn’t have the same amount of saturated fat that is typically found in red and processed meat, Dr. Jackson says. “Saturated fat is the major dietary cause of ischemic heart disease,” Jackson adds.
Limitations of the Study
There are several caveats to the study findings. For starters, most of the smaller studies included in the analysis used food frequency questionnaires to assess meat intake, which don’t always provide a reliable picture of how people eat. Another limitation of the analysis is that many of the smaller studies only assessed dietary habits at a single point in time, and it’s possible that people’s eating habits changed in ways that might have influenced their risk of developing heart disease. In addition, it’s not clear from the study how people prepared their food or what cuts of meat they ate, both of which might influence their risk of developing ischemic heart disease, Jackson says. For example, choosing lean cuts of red meat and trimming any visible fat may help reduce the risk of ischemic heart disease associated with this food, Jackson says. It can be more difficult to remove fat from certain processed meats, but with products like bacon where fat is visible it can be trimmed, Jackson adds. “You don’t need to eliminate red and processed meat from your diet, particularly if you remove the visible fat,” Jackson says. “However, limiting meat to once or twice a week is a good plan.”
Some Earlier Studies Link Meat to Heart Disease but Others Don’t
The latest study on the connection between red and processed meat and ischemic heart disease comes on the heels of several previous reviews that have arrived at conflicting conclusions. For example, one previous research review, published in May 2010 in Circulation, found no association between red meat and the risk of developing or dying from ischemic heart disease. Another review, published in June 2014 in the British Journal of Nutrition, found no association between red or processed meat and the risk of dying from ischemic heart disease. More recently, however, one review published in 2019 in Critical Reviews in Food Science and Nutrition and another review published in November 2019 in the Annals of Internal Medicine both found red meat and processed associated with an increased risk of developing ischemic heart disease. The results from the latest offer another piece of evidence suggesting that red and processed meat may indeed lead to a higher risk of ischemic heart disease, says coauthor Anika Knüppel, PhD, a nutritional epidemiologist at the University of Oxford in England. “Whether one person gets ischemic heart disease or not will depend on various factors, such as genetics, family history and lifestyle factors — red and processed meat intake is one such factor,” Dr. Knüppel says. Still, the latest study results suggest “limiting processed meat to a minimum sounds like a good approach,” Knüppel adds.
Heart-Healthy Diet Approaches
Limiting red and processed meat is part of a heart-healthy diet, according to 2019 recommendations from the American Heart Association (AHA). Two dietary patterns that are endorsed by the AHA: the Mediterranean diet and the DASH (Dietary Approaches to Stop Hypertension) diet. Both emphasize consumption of fruits, vegetables, whole grains, vegetable oils, nuts, fish, and poultry, as well as limiting red meat, sugars, and salt. To prevent ischemic heart disease, “it is also important to have appropriate portion size control and balance caloric intake and physical activity to maintain a healthy weight,” says Frank Hu, MD, PhD, professor and chair of the department of nutrition at the Harvard T.H. Chan School of Public Health in Boston. People who already have ischemic heart disease may help heart attacks and improve their survival odds if they modify their eating habits to adopt a more heart-healthy diet, Dr. Hu says. “Cut back on red and processed meat consumption and replace it with healthier protein sources such as poultry, fish, nuts, and legumes,” Hu advises.
