Red meat consumption can increase the risk of heart disease by altering the gut microbiome
The finding has uncovered a new target for possible treatments to combat heart disease.
New research in the US suggests the consumption of red meat may be a primary driver of atherosclerotic cardiovascular disease or ASCVD, which is responsible for over 15 per cent of all deaths globally – making it officially the most common cause of death in the world.
ASCVD can kill you in a variety of ways, including heart attack, coronary heart disease, cardiac arrest and stroke, but its root causes have long been the subject of debate. Various factors have been posited for ASCVD risk, including salt and fat consumption, cholesterol levels and red meat intake, but conclusive evidence has proved hard to come by.
The new study, the results of which were published this week in the journal Arteriosclerosis, Thrombosis, and Vascular Biology, was carried out by a team from the Tufts University’s Friedman School of Nutrition Science and Policy and the Cleveland Clinic Lerner Research Institute, drawing on data gathered by the National Institute of Health’s 12-year Cardiovascular Health Study.
The latter involved a cohort of nearly 4,000 US adults over the age of 65 recording their dietary intake while having their blood checked regularly for levels of particular biomarkers linked to the human gut microbiome. The Tufts/Lerner research took that data and compared it with the long-term health outcomes of the study participants over 12 and a half years.
They found that patients who consumed more red meat – whether processed or unprocessed – were more likely to go on to develop ASCVD, with those that ate 1.1 servings per day having a 22 per cent increase in risk than those that ate no meat when averaged out.
They also found that risk is mediated by a variety of other factors, including blood levels of glucose and insulin, and that about 10 per cent of it can be attributed to levels of a particular compound called triymethylamine N-oxide or TMAO. TMAO is a metabolite produced by gut bacteria from nutrients abundant in red meat, most notably the metabolic compound L-carnitine.
No similar link could be found for subjects whose diet was high in poultry, fish or eggs.
“These findings help answer long-standing questions on mechanisms linking meats to risk of cardiovascular diseases,” said co-author Meng Wang, a post-doctoral fellow at the Friedman School.
“The interactions between red meat, our gut microbiome and the bioactive metabolites they generate seem to be an important pathway for risk, which creates a new target for possible interventions to reduce heart disease.”
It is hoped that the study may lead to new dietary-based approaches to preventing ASCVD in older patients, who are more likely to develop ASCVD.
Further research is needed to find out whether the link they found holds true across different age groups and populations, or whether it is specific to older adults in the western world, the team add.
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Russell Deeks is a freelance writer with nearly 30 years’ journalism experience, working across the fields of music, technology and science – which, he says, cross over more often than you might think. Despite the drawback of holding a degree in English & American Literature, he has been a regular contributor to BBC Science Focus since 2006.