Lean Beef in Mediterranean Diet Doesn’t Appear to Raise Heart Disease Risk, Penn State Study Finds
UNIVERSITY PARK, PA – May 16, 2025 - Incorporating lean beef into a Mediterranean-style diet may not increase heart disease risk, according to new research from Penn State. The study, published in the Journal of the American Heart association, challenges previous assumptions about red meat and cardiovascular health.
Researchers led by Petersen’s laboratory group investigated the impact of lean beef consumption on gut microbiota and metabolites related to heart health. Their findings suggest that, within a healthy dietary pattern, lean beef doesn’t necessarily elevate levels of trimethylamine N-oxide (TMAO), a compound linked to increased risk of heart disease. Actually, earlier research from the same team showed a Mediterranean diet with lean beef resulted in lower blood pressure compared to a typical American diet.
A review of existing studies, led by doctoral student Fatemeh Jafari, further complex the understanding of TMAO and red meat. The review revealed that roughly half of the studies examined found no increase in TMAO levels associated with beef consumption.
“The most crucial way to reduce risk is to establish healthy eating habits,” the researchers emphasized, advocating for increased intake of vegetables, fruits, and whole grains while limiting saturated fats.
However, they cautioned against misinterpreting the results. “This evidence does not mean you can necessarily eat a week’s worth of beef – such as, a single, 17.5-ounce steak – at one time and see the same results,” explained Petersen. the findings also do not apply to non-lean beef or processed meats like sausage or salami. The study population consisted of relatively young, healthy individuals, necessitating further research in older adults or those with pre-existing heart conditions.
The research was funded by the National Cattlemen’s Beef Association (through the Beef Checkoff) and Penn State.
Reference: DiMattia ZS, Zhao J, Hao F, et al. Effect of varying quantities of lean beef as part of a mediterranean‐style dietary pattern on gut microbiota and plasma, fecal, and urinary metabolites: a randomized crossover controlled feeding trial.J Am Heart Assoc. 2025;14(19):e041063. doi: 10.1161/JAHA.125.041063
