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Two new studies were published this week that put the heart-health benefits of eating less red meat and more plant-based proteins in the spotlight.

The first study from the Harvard T.H. Chan School of Public Health and Purdue University, “Meta-Analysis of Randomized Controlled Trials of Red Meat Consumption in Comparison With Various Comparison Diets on Cardiovascular Risk Factors,” was published April 8 in the journal Circulation.

Marta Guasch-Ferré, who is a research scientist in the Department of at Harvard T.H. Chan School of Public Health and holds a Ph.D. in nutritional epidemiology, was the study’s lead author.

According to Guasch-Ferré and her colleagues—who analyzed data from 36 randomized controlled trials involving 1,803 participants—this is the first meta-analysis of randomized controlled trials to specifically examine the impact that substituting healthy plant-based proteins for red meat has on cardiovascular disease (CVD) risk factors.

"Previous findings from randomized controlled trials evaluating the effects of red meat on cardiovascular disease risk factors have been inconsistent. 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," Guasch-Ferré said in a statement.

In the paper’s conclusion, the authors write:

“Findings from the present systematic review and meta-analysis showed that total red meat intake did not differentially influence blood lipids and apolipoproteins, with the exception of triglycerides, when all comparison diets were analyzed together. In comparison with red meat, consumption of high-quality plant protein sources (i.e., soy, nuts, and legumes) leads to more favorable changes in blood concentrations of total cholesterol and LDL-C.”

Harvard’s Meir Stampfer, who is a professor of epidemiology and nutrition, was the study’s senior author. In a statement, Stampfer said, "Asking 'Is red meat good or bad?' is useless. 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."

Researchers from the University of Eastern Finland conducted the second new study on the heart-health benefits of eating more plant-based proteins and less dietary protein from animals. This paper, “Dietary Proteins and Protein Sources and Risk of Death: The Kuopio Ischaemic Heart Disease Risk Factor Study,” was published April 9 in The American Journal of Clinical Nutrition.

For this study, the researchers used statistical date from the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) that tracked the dietary habits of 2,641 Finnish men, aged 42–60 years old at baseline between 1984–1989. For their most recent analysis, the researchers examined mortality rates and causes of death two decades later.

The Finnish researchers found that study participants who consumed more red meat as a percentage of their total protein consumption were at higher risk of CVD and death than study participants who ate a diet with a more balanced ratio of animal and plant-based proteins.

In the study conclusion, the authors write: "[A] higher ratio of animal to plant protein in diet and higher meat intake were associated with increased mortality risk. Higher total protein intake appeared to be associated with mortality mainly among those with a predisposing disease."

There was a caveat: In a statement, first author Heli Virtanen from the University of Eastern Finland said, "However, these findings should not be generalized to older people who are at a greater risk of malnutrition and whose intake of protein often remains below the recommended amount."

Author's Note: "I Like Mine with Lettuce and Tomato, Heaven on Earth with an Onion Slice"

"To safeguard one’s health at the cost of too strict a diet is a tiresome illness indeed." —François de La Rochefoucauld (Reflexions Ou Sentences Et Maximes Morales)

As a public health advocate, I feel obligated to report on these two recent studies that just "put red meat back in the hot seat." That said, I tend to take most new dietary research and recommendations with a grain of salt. Food fads will always come and go. Before making any radical changes to your diet, please use common sense and consult with your primary care physician.

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Anecdotally, I know from first-hand experience that any time I start depriving myself of so-called "forbidden" foods that it sets off a vicious cycle of craving and binging. Therefore, I try to listen to my body and focus more on portions and moderation than any dietary extremes. For example, I love cheeseburgers and filet mignon. If left to my own devices, I might eat red meat every night of the week. But, because I do believe that eating too much red meat might increase my CVD risk, I consume these sources of animal protein in moderation.

"Cheeseburger in Paradise" is a tongue-in-cheek classic '70s song by Jimmy Buffet that sums up some of the psychological pitfalls of trying to stop eating red meat, cold turkey, that I've experienced personally. Buffet sings, "Tried to amend my carnivorous habits, made it nearly seventy days. Losin' weight without speed, eatin' sunflower seeds, drinkin' lots of carrot juice... But at night, I'd have these wonderful of some kind of sensuous treat. Not zucchini, fettuccini, or bulgur wheat, but a big warm bun and a huge hunk of meat!"

Over a decade ago, when I wrote a chapter on nutrition for The Athlete's Way, I summed up my about diet:

"Experts are convinced that making the right dietary choices can improve health and protect us from certain diseases. Unfortunately, no one can seem to agree on what the exact choices should be for every circumstance. When it comes to what people should eat, there are lots of opinions and little certainty. Nutrition is a potentially confusing and often misunderstood field. Therefore, the nutrition prescriptive set forth in this chapter is: Use common sense, eat intuitively, keep track of calories in/calories out, stay hydrated, and eat a variety of foods. You also want to avoid food fads. Don’t make dietary choices based on newspaper headlines, and avoid making any foods taboo. That’s it in a nutshell. Food should be a source of joy, not ."

Although I wrote the above passage eons ago, I still think it's "timeless" diet advice in many ways.

Based on the latest research studies mentioned in this post, back on red meat appears to reduce cardiovascular disease risk. Nevertheless, beyond reporting on the most recent findings by Guasch-Ferré et al. (2019) and Virtanen et al. (2019) I don't have any specific prescriptive dietary advice about ideal ratios of animal protein vs. plant-based protein.