12 January - 20 June 2016

Compound found in red meat may be the link to increased risk of CVD

10 April 13

A study published in the journal Nature Medicine by Hazen et al. has added to the debate on why high meat consumption is linked to cardiovascular disease risk.  It has been previously suggested that saturated fats and cholesterol, which are found in meat, are the cause of increased risk, however a recent meta-analysis of prospective cohort studies found no association between dietary saturated fat intake and CVD.  Previous research has indicated that microbiota of humans is linked to intestinal health, immune function, bioactivation of nutrients and vitamins and also is involved in complex disease phenotypes such as obesity and insulin resistance.  L-carnitine is abundant in red meat and is a substance that helps the body turn fat into energy.  It is available as a supplement and also used as an ingredient in energy drinks, however the study states that our body naturally produces all we need.  Hazen et al found that bacteria living in the human digestive tract metabolise the compound carnitine, turning it into trimethylamine-N-oxide (TMAO), a metabolite which the researchers previously linked in a 2011 study to the promotion of atherosclerosis in humans.  Hazen et al investigated carnitine and TMAO levels of omnivores, vegans and vegetarians.  Following ingestion of L-carnitine at the same amounts, omnivore participants produced more TMAO than did vegans or vegetarians.  Hazen et al. also found that the bacterial taxa in human faeces were associated with both blood TMAO levels and dietary status.  The authors indicate that the bacteria present in our digestive traces are therefore influenced by long term dietary patterns. They note that a diet high in carnitine changes gut microbe composition to one that likes carnitine.  Vegans and vegetarians have a significantly reduced capacity to synthesize TMAO from carnitine.  From examining clinical data of 2,595 patients undergoing elective cardiac evaluations, Hazen et al found that increased carnitine levels in patients predicted increased risks for cardiovascular disease and major cardiac events like heart attack, stroke and death, but only in subjects with concurrently high TMAO levels.  They also examined the cardiac effects of a carnitine-enhanced diet in normal mice compared to mice with suppressed levels of gut microbes, and discovered that TMAO alters cholesterol metabolism at multiple levels, explaining how it enhances atherosclerosis.

share this article
RSSL endeavours to check the veracity of news stories cited in this free e-mail bulletin by referring to the primary source, but cannot be held responsible for inaccuracies in the articles so published. RSSL provides links to other World Wide Web sites as a convenience to users, but cannot be held responsible for the content or availability of these sites. This document may be copied and distributed provided the source is cited as RSSL's Food e-News and the information so distributed is not used for profit.

Previous editions

Load more editions

Make an Enquiry