Ditching red meat in favour of vegan substitutes cuts heart disease risk, say scientists

Swapping red meat for certain plant-based meat alternatives can cut the risk of suffering heart disease, scientists have found.

American researchers who studied people eating both meat and meat substitutes discovered those who ate red meat at least twice a day had higher levels of a molecule that makes people susceptible to cardiovascular ill health.

A team at Stanford Medicine in California gathered a group of more than 30 people and assigned them to two different diets, each one for eight weeks. One diet involved at least two daily servings of meat – mostly red – and one meant at least two daily servings of plant-based meat.

The researchers then measured people’s levels of a molecule, trimethylamine N-oxide, or TMAO, which has been linked to cardiovascular disease risk.

People who ate the red-meat diet during the first eight-week phase had an increase in TMAO, while those who ate the plant-based diet first did not.

When the groups switched diets, those who changed from meat to plants had a drop in TMAO, which was expected. But those who switched from plant to meat did not have an increase in TMAO.

“It was pretty shocking; we had hypothesised that it wouldn’t matter what order the diets were in,” said Christopher Gardner, professor of medicine the Stanford Prevention Research Center.

He said it turns out that bacteria responsible for creating TMAO in the gut are thought to flourish in people whose diets are red-meat-heavy. But avoiding meat curbed the body’s capacity for making the dangerous molecule.

“So 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.

The study was funded by Beyond Meat, which makes plant-based meat alternatives, and products from the company were used in the experiment.

Many new meat alternatives, such as Beyond Meat, have relatively high levels of saturated fat and added sodium, and are considered highly processed foods. These factors have been shown to contribute to cardiovascular disease risk.

“There’s been this sort of backlash against these new meat alternatives,” said Prof Gardner, a vegetarian. “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?”

As well as the TMAO falling, participants’ levels of “bad” cholesterol dropped and they lost weight during the plant-based portion of the diet.

“The modest weight loss observed when participants substituted the plant-based meats in place of the red meats is an unexpected finding, since this was not a weight-loss study,” said Anthony Crimarco, lead author of the paper, which is published in the American Journal of Clinical Nutrition.