Just a few days ago there were multiple news reports about a study in Nature Medicine by researchers at the Cleveland Clinic that suggested that there was supposedly one more reason not to eat red meat it contains high levels of the amino acid L-carnitine, which is metabolized by bacteria in the gut to give trimethylamine-N-oxide (TMAO), a substance that could play a part in atherosclerosis.
Well, sometimes science is like the weather. You wait a day and it changes.
Today, a report of a meta-analysis of 13 controlled studies reported in the Mayo Clinic Proceedings arrived at the exact opposite conclusion that supplemental L-carnitine provides significant cardioprotective properties to patients that had previously had heart attacks.
The analysis reviewed 13 studies containing over 3,600 patients that were published between 1989 and 2007, and it revealed some rather startling findings.
When compared to patients taking a placebo, those taking L-carnitine had a 27% reduction in all cause mortality, including a 65% reduction of ventricular arrhythmias (the most serious kind) and a 40% reduction in angina. All results were statistically significant.
So, whom do you believe?
ACSH s Dr. Josh Bloom thinks this is a no-brainer: The Cleveland Clinic study measured the effects of TMAO in mice, and used limited epidemiological evidence to link this to humans, including a fair amount of speculation. He continues, On the other hand, the Mayo Clinic Proceedings study has actually discovered a very well-defined benefit for heart attack patients, with very good statistics to back up their findings.
