Unveiling the hidden heart risk. How red meat consumption increases cardiovascular threats

The 2022 study, published in Arteriosclerosis, Thrombosis, and Vascular Biology, suggests that the human body processes red meat differently than other foods when it reaches the intestines.

The research team studied approximately 4000 individuals with an average age of 73. Their medical history, blood biomarkers, and eating habits were under analysis throughout the study.

Special attention was given to fasting blood samples. These were examined for several biomarkers associated with red meat consumption, namely TMAO, gamma-butyrobetaine, and crotonobetaine.

The obtained blood information was cross-referenced with the participants' dietary questionnaires, focusing on their consumption of animal food sources.

The study results show a significant higher risk of atherosclerotic cardiovascular disease in participants who consumed more red meat. On the other hand, the consumption of fish, poultry, and eggs did not result in a significant increase in cardiovascular disease risk.

But how exactly does the intake of red meat link to increased cardiovascular disease risk through the intestines? The involved biomarkers suggest that the interaction between red meat and the intestines may hold the answer.

In the participants' blood samples, scientists noted increases in metabolite levels, particularly TMAO, which are often associated with red meat consumption.

These metabolites, especially TMAO, are produced by gut bacteria during the digestion of red meat, rich in a compound called L-carnitine.

It is thought that an elevation in TMAO and other similar metabolites found in the participants' blood samples may contribute to the increased risk of cardiovascular disease.

According to the team, these gut-produced metabolites could affect blood sugar levels and cause inflammation in the body, explaining the connection between red meat consumption and cardiovascular problems.

Thus, blood sugar control and the level of inflammation could be more critical to heart health than previously believed.

Meng Wang, the study's co-author and a postdoctoral researcher at the Friedman School of Nutrition Science and Policy at Tufts University cites the need for more research to fully understand this relationship.

"We need more research to understand the potential health effects of L-carnitine and other substances in red meat, such as heme iron, which is associated with type 2 diabetes. We should avoid focusing solely on the risks of consuming saturated fats," Wang suggests.

However, should we be worried about red meat?

The current study implies that gut responses to red meat intake might provide clues about why its consumption is frequently linked with cardiovascular health problems.

Nonetheless, several aspects of this study limit and may have affected the findings. Firstly, participants self-reported their diets, thus introducing the possibility of cognitive or communicative errors.

Secondly, since this is an observational study, the findings do not pinpoint a clear cause-effect relationship between red meat consumption and cardiovascular diseases. Nor does it provide ways to directly alter the compounds produced by gut microbes.