How swapping plant-based products for meat may improve cardiovascular health: New study

Scientists at Stanford Medicine concluded lower levels of LDL cholesterol.

August 13, 2020, 4:02 PM

As more consumers turn to plant-based meat alternatives, a new study that swapped Beyond Meat for beef, pork and chicken found that the non-animal protein products lowered some cardiovascular risk factors.

The small study published Tuesday in the American Journal of Clinical Nutrition conducted by Stanford Medicine found that when participants swapped their protein from animal to plant-based meat participants saw a drop in LDL cholesterol, reduced TMAO levels and in some cases, lost an average of two pounds.

PHOTO: Female scientist analyzing medical sample in test tube. Young researcher is wearing lab coat. She is concentrating while working in laboratory.
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"Among generally healthy adults, contrasting Plant with Animal intake, while keeping all other dietary components similar, the Plant products improved several cardiovascular disease risk factors, including TMAO; there were no adverse effects on risk factors from the Plant products," the scientists concluded from the 36 participants.

The researchers conducted this as a 16-week crossover study, which splits participants into two groups for dietary interventions.

Half of the participants ate at least two servings of plant-based alternative meat per week and half ate at least two servings of animal meat per week. After eight weeks, the people eating the plant-based "meat" started eating real meat for eight weeks, and the people eating real meat started eating plant-based "meat" for eight weeks.

This study did not include a washout period, which would ordinarily provide a small break in between the intervention switch in which participants go back to eating like normal for a bit.

Participants' levels of LDL cholesterol, sometimes referred to simply as "bad" cholesterol, dropped on average 10.8 milligrams per deciliter, which researchers found to be statistically significant.

PHOTO: Closeup of two uncooked vegan burger patties.
Closeup of two uncooked vegan burger patties.
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The lead researcher Christopher Gardner, Ph.D., professor of medicine at the Stanford Prevention Research Center, said one of the main outcomes they looked to track was the levels of a molecule, trimethylamine N-oxide, or TMAO. TMAO has been linked to cardiovascular disease and Gardner called it "an emerging risk factor."

The scientists found that TMAO levels were lower when participants were eating the plant-based meat diets.

"For the participants who had the plant-based diet first, during which they ate no meat, we basically made them vegetarians, and in so doing, may have inadvertently blunted their ability to make TMAO," he said. "Whether this type of approach could be used as a strategy for decreasing cardiovascular disease risk remains to be seen."

Additional findings from the study included that participants lost two pounds, on average, during the plant-based portion of the study. They also found similar sodium intake and blood pressure levels between the animal-based and plant-based phases of the study, which they say debunks the myth that consuming plant-based meats results in higher sodium intake.

The real meat used during the meat intervention was a combination of beef, pork and chicken products. The beef product used 80% lean and 20% fat ground beef; while that is a common red meat product for most Americans, the meat itself had noticeably higher saturated fat per serving than did the plant-based "meat."

ABC News medical unit resident Nate Wood, MD, explained that a comparison using 90-95% lean ground beef or other lean meat products may have provided different results for saturated fat that likely would not have been present.

The "swap meat study" was funded by an unrestricted gift from Beyond Meat and researchers used the company's products to compare the health effects of meat with plant-based alternatives, however Stanford Medicine said in a press release said that Beyond Meat was not involved in designing or conducting the study and did not participate in data analysis.

Additional funding for the research was provided by the National Institutes of Health.