Though it was once common to claim that red meat caused heart disease, those turned out to be flawed epidemiological conclusions based on observational studies and things like food diaries. 

A new study finds red meat metabolite levels high in acute heart failure patients, and seeks to re-establish the link between red meat and heart disease using biological markers. Patients with acute heart failure often have high levels of the metabolite trimethylamine N-oxide (TMAO) and red meat is a dietary source. Red meat is a source of L-carnitine which is broken down by gut bacteria to form TMAO. Some papers have linked TMAO with mortality risk in chronic heart failure but no association in acute heart failure has been established.

A team led by Professor Toru Suzuki from the University of Leicester’s Department of Cardiovascular Sciences measured circulating TMAO levels in approximately 1,000 patients admitted to University Hospitals of Leicester NHS Trust with acute heart failure. They also suggest involvement of the gut microbiota and diet in outcomes of acute heart failure, which throws the conclusions into chaos, since microbiota is not linked to anything at all but selling expensive yogurt.

Nonetheless, the authors created an association between circulating levels of a metabolite of this process with prognosis of acute heart failure.

Professor Suzuki said: “Patients with acute heart failure showed higher levels of the oxidised metabolite TMAO in those that died or had a repeat admission to hospital with heart failure within the first year.

Citation: Trimethylamine N-oxide and prognosis in acute heart failure, Heart, DOI: 10.1136/heartjnl-2015-308826