Choose plants over red meat to keep your heart healthy. That is the recommendation of a new study that found diets with high-quality plant protein sources could help reduce cardiovascular disease risk factors, mainly lowering risks of heart attacks. 

The findings, published in the journal Circulation, come from the first meta-analysis of trials that examined the health effects of red meat compared to other types of food. The researchers said that plant alternatives, such as legumes, soy and nuts, could provide better benefits to the heart by reducing levels of bad cholesterol.

"Previous findings from randomized controlled trials evaluating the effects of red meat on cardiovascular disease risk factors have been inconsistent,” Marta Guasch-Ferré, lead author of the study, said in a statement posted on EurekAlert. “But our new study, which makes specific comparisons between diets high in red meat versus diets high in other types of foods, shows that substituting red meat with high-quality protein sources lead to more favorable changes in cardiovascular risk factors."

The research team from Harvard T.H. Chan School of Public Health and Purdue University analyzed data from 36 randomized controlled trials that involved 1,803 participants. They divided the participants into groups that either ate diets with red meat or more of other types of foods, like chicken, fish, carbohydrates or plant proteins.

The researchers focused on their blood concentrations of cholesterol, triglycerides, lipoproteins and blood pressure that are all known as contributing to heart problems. 

Results show that the people who consumed more red meat had higher tryglyceride concentrations than the other groups, especially those who ate plant alternatives. This finding backs previous research that suggested nuts and other plant sources of protein provide lower risks of heart attacks.

"Asking 'is red meat good or bad?' is useless," Meir Stampfer, a professor of epidemiology and nutrition and senior author of the study, said. "It has to be 'compared to what?' If you replace burgers with cookies or fries, you don't get healthier. But if you replace red meat with healthy plant protein sources, like nuts and beans, you get a health benefit."

The researchers recommended that following healthy vegetarian and Mediterranean-style diets as both approach could better health benefits and promote environmental sustainability.

They also noted further studies are needed to see the direct impacts of red meat on the body as well as other type of diets.