Heart Disease and the chemical TMAO connection – Part 2
Now that the hype around this research has died down I thought it was a good idea for a more in depth look at it.
“This study provides another piece in the jigsaw puzzle showing the links between atherosclerosis and diet and lifestyle. The study is comprehensive and demonstrates a mechanism that may help to explain the observed associations between the consumption of red meat and the risk of CVD. This does not mean that we need to change current dietary recommendations because the advice is to limit the intake of red meat anyway…”
Nutrition expert Professor Brian Ratcliffe, Robert Gordon University in Scotland.
“This is certainly an interesting discovery and sheds some light on why red meat might have an impact on heart health. These scientists have served up a good reminder for us to think about alternative sources of protein if we regularly eat a lot of red or processed meats”
Victoria Taylor, senior dietitian at the British Heart Foundation.
The researchers said “We demonstrate here that metabolism by intestinal microbiota of dietary l-carnitine; a trimethylamine abundant in red meat, also produces TMAO and accelerates atherosclerosis. Omnivorous human subjects produced more TMAO than did vegetarians following ingestion of l-carnitine through a microbiota-dependent mechanism. The presence of specific bacterial taxa in human feces was associated with both plasma TMAO concentration and dietary status. Plasma l-carnitine levels in subjects undergoing cardiac evaluation predicted increased risks for both prevalent cardiovascular disease and incident major adverse cardiac events (myocardial infarction, stroke or death), but only among subjects with concurrently high TMAO levels”.
Meat = Carnitine = TMAO = Heart Disease?
The latest research has uncovered yet another reason behind the direct link from meat to heart disease. These doctors found a little-studied chemical that is created by the body’s bacteria after you eat meat. The liver immediately converts this chemical into a chemical called TMAO. TMAO then goes into the blood and directly creates atherosclerosis; the #2 cause of heart disease death in the world. The researchers analyzed blood from more than 2,500 people, looking to see what predicted heart attacks (independent of smoking, high cholesterol and blood pressure), and found the effect was driven solely by TMAO.
The researchers found that TMAO caused heart disease in mice and then after checking human blood samples, found that TMAO levels also predict heart attack risk in humans. TMAO basically enables cholesterol to get into artery walls and also prevents the body from excreting excess cholesterol; creating atherosclerosis. The simple rule is; the more meat eaten, the higher the levels of TMAO in the blood, the more likely you are to create atherosclerosis = heart disease = early death. In a 2011 study, choline (found in high amounts in meat), was shown to produce trimethylamine, and then processed in the liver to create TMAO, raising atherosclerosis. This study also found heart disease is influenced by how the micro-organisms in digestive tracts metabolize lecithin, a compound with a structure similar to carnitine.