In a recently concluded study at Stanford Medicine, the researchers have found leaving red meat for certain plant-based meat alternatives can improve some cardiovascular risk factors.
The small study was funded by an unrestricted gift from Beyond Meat, which makes plant-based meat alternatives, and used products from the company in comparing the health effects of meat with plant-based alternatives.
Beyond Meat was not involved in designing or conducting the study and did not participate in data analysis.
It may seem obvious that a patty made of plants is a healthier option than a hamburger. But many of the new meat alternatives, such as Beyond Meat, have relatively high levels of saturated fat and added sodium and are considered highly processed foods, meaning they are made with food isolates and extracts as opposed to whole beans or chopped mushrooms.
All of these factors have been shown to contribute to cardiovascular disease risk, said Christopher Gardner, PhD, professor of medicine at the Stanford Prevention Research Center.
“There’s been this sort of backlash against these new meat alternatives,” Gardner said.
“The question is, if you’re adding sodium and coconut oil, which is high in saturated fat, and using processed ingredients, is the product still actually healthy?”
To find out, Gardner and his team gathered a group of more than 30 individuals and assigned them to two different diets, each one for eight weeks.
One diet called for at least two daily servings of meat — the options available were primarily red meat — and one called for at least two daily servings of plant-based meat.
In particular, the researchers measured the levels of a molecule, trimethylamine N-oxide, or TMAO, in the body; TMAO has been linked to cardiovascular disease risk. They found that TMAO levels were lower when study participants were eating plant-based meat.
A paper describing the results of the study will be published Aug. 11 in the American Journal of Clinical Nutrition. Gardner is the senior author of the paper. Postdoctoral scholar Anthony Crimarco, PhD, is the lead author.
Gardner, a longtime vegetarian, is a staunch proponent of eating whole foods, with a particular emphasis on vegetables.
As nearly all plant-based meats are fairly high in saturated fats and classified as highly processed foods — Beyond Meat included — Gardner wanted to study how they affect the body compared with red meat.
He and his team conducted a study that enrolled 36 participants for 16 weeks of dietary experimentation.
Gardner designed the research as a crossover study, meaning participants acted as their own controls.
For eight weeks, half of the participants ate the plant-based diet, while the other half ate the meat-based diet consisting of primarily red meat, although some participants ate a small amount of chicken. Then they switched. Regardless of which diet participants were on, both groups had on average two servings of meat or plant-based alternatives per day, carefully tracking their meals in journals and working with members of Gardner’s team to record their eating habits.
The team took precautions to eliminate bias throughout the study, including working with a third party at Stanford, the Quantitative Sciences Unit, to analyze the data once all participants had finished their 16-week dietary interventions.
“The QSU helped us draw up a statistical analysis plan, which we published online before the study was completed,” Gardner said. “That way our plan was public, and we were accountable for the specific primary and secondary outcomes that we had initially said we wanted to go after — namely, the participants’ levels of TMAO, blood cholesterol, blood pressure and weight.”