The ketogenic diet may be all the rage today, but new research published by Harvard T.H. Chan School of Public Health and Purdue University suggests that plant proteins are responsible for sustaining life and reducing the risk of developing heart disease.

The study was published in the journal Circulation earlier this year. Reportedly, it is the first meta-analysis of randomized controlled trials examining the health effects of red meat by substituting it for healthy plant proteins.

“Previous findings from randomized controlled trials evaluating the effects of red meat on cardiovascular disease risk factors have been inconsistent,” explained Marta Guasch-Ferré, research scientist in the Department of Nutrition and lead author of the study. “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.”

For the study, data from 36 randomized controlled trials which involved 1,803 participants was used. The researchers compared people who ate diets with red meat with people who ate more of other types of foods (including chicken, fish, carbohydrates, or plant proteins such as legumes, soy, or nuts). They looked at blood concentrations of cholesterol, lipoproteins, blood pressure, and triglycerides. All are risk factors for cardiovascular disease (CVD).

When the diets with red meat were compared with all other types of diets combined, there were no significant differences in total cholesterol, lipoproteins, or blood pressure. However, diets that were higher in red meat did lead to higher triglyceride concentrations than comparison diets. On the contrary, researchers found that diets higher in high-quality plant protein sources, such as legumes and nuts, resulted in lower levels of both total and LDL (“bad”) cholesterol when compared to diets rich in red meat.

Chiro Eco reports:

The results are consistent with long-term epidemiologic studies showing lower risks of heart attacks when nuts and other plant sources of protein are compared to red meat, the authors said. The findings also suggest that the inconsistencies found in prior studies regarding the effects of red meat on cardiovascular risk factors may be due, in part, to the composition of the comparison diet. They recommended that future studies take specific comparisons into account.

Meir Stampfer, professor of epidemiology and nutrition and senior author of the study, says that “Asking ‘Is red meat good or bad’ is useless.” He explained, “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 authors recommend adhering to healthy vegetarian and Mediterranean-style diets. Not only are both diets highly nutritious but they promote environmental sustainability.