For years, the healthiness of red meat has been debated.
While several studies have pointed to the cons of consuming beef, new research has found that when lean beef is eaten with a Mediterranean diet, it may help lower risk factors for heart disease. Those risk factors included LDL cholesterol — high levels of which can lead to cholesterol build up in the arteries.
“When you create a healthy diet built on fruits, vegetables, and other plant-based foods, it leaves room for moderate amounts of other foods like lean beef,” said Jennifer Fleming, assistant teaching professor of nutrition at Penn State. “There are still important nutrients in beef that you can benefit from by eating lean cuts like the loin or round, or 93% lean ground beef.”
“This study highlights the importance of including lean beef in a Mediterranean dietary pattern that can yield heart-healthy benefits,” added David J. Baer, research leader at the United States Department of Agriculture – Agricultural Research Service, who served as a co-principal investigator on the study.
The findings were published in the American Journal of Clinical Nutrition earlier this month and involved 59 participants in a randomized controlled study.
For four weeks each, all participants ate each diet, which had different amounts of lean beef in combination with the Mediterranean diet. There was a one-week break between each diet period. Researchers also drew blood samples at the study’s onset and following each diet period.
Levels of beef varied in each diet, but the Mediterranean diet plan contained 41% calories from fat, 42% from carbohydrates and 17% from protein. The control average American diet was used along with a diet that had 0.5 ounces of beef a day — this matches the recommended amounts in the Mediterranean diet pyramid. Another diet had 2.5 ounces a day or the amount a typical American eats in one day. A third diet had 5.5 ounces a day. This amount has been linked to specific heart health benefits in prior research.
The beef consumed in these diet periods were either lean or extra lean. All diet periods included a main fat source of olive oil, three to six servings of fruits and at least six daily servings of vegetables.
Fleming and the team were able to use nuclear magnetic resonance technology to measure the number and size of lipoprotein particles, which are part of LDL cholesterol. According to Fleming, this was one of the first randomized controlled trials of the Mediterranean diet that used that method.
“This is important because there is growing evidence to suggest that LDL particle number is more strongly associated with cardiovascular disease risk than total blood LDL concentrations alone,” Fleming said. She added that the team could also identify changes in specific human proteins, “which are also associated with increased CVD risk.”
After analyzing the data, researchers saw lower LDL cholesterol in all participants after the Mediterranean diet periods compared to the typical American diet. Still, the total number of LDL particles was only markedly reduced in the diet periods that included 0.5 or 2.5 ounces of beef a day compared to the typical American diet.
“Our study helped illustrate the benefits associated with a healthy Mediterranean dietary pattern that embodies balance, variety and the inclusion of nutrient-rich components, which can include low to moderate amounts of lean beef,” Fleming said.
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