Marco: please provide original PubMed citations.
Thanks - Dr U
Marco: please provide original PubMed citations.
Thanks - Dr U
Sorry, regarding the carnitine/theoretical risk, I know of no actual papers that directly refute the study, however, the study itself I feel is flawed for many reasons, to name a few:
1) The researchers based many of their conclusions about TMAO on research done in mice, so, we don't really know whether or not TMAO actually causes CVD in humans.
2) The human component of their study consisted of only six people: one vegan and five meat-eaters. Six people is not even close to being enough subjects to draw conclusions.
3) Any study that says that TMAO causes CVD needs to deal with the fact that a person eating animal flesh of any kind is going get a lot more naturally-occuring carnitine than when you take a few hundred mg's of carnitine.
In addition, a Mayo Clinic meta-analysis was released that looked at 3,600 patients and found huge CV benefits in those who supplemented with L-carnitine (one of the main reasons I use it). The study represented the largest, most powerful scientific review of carnitine's CV benefits to date:
https://www.ncbi.nlm.nih.gov/pubmed/23597877
The Mayo Clinic study found carnitine supplementation was associated with a 27% reduction in all-cause mortality, a 65% reduction in ventricular arrhythmias, and a 40% reduction in angina symptoms in patients who had experienced a heart attack. The media was quick to bypass this study, however.
Does that mean it's all b.s. and there's no risk? Nope. However, I think there are, as with many things of controversial nature, modulating and offsetting factors, i.e. one's gut microbiome:
Probiotic intervention can attenuate TMAO:
https://www.ncbi.nlm.nih.gov/pubmed/28511293
For me, it comes down to the risk vs benefits, and the benefits, both from my first-hand experience and that of the well-documented research, outweigh the theoretical risk. The carnitine/thyroid conflict, however, is another matter altogether that I guess until I do my own n-1 experiment, remains to be seen.
On a side note, carnitine is not the only player being demonized in the TMAO scourge; choline and betaine, two other highly beneficial nutrients, are just as "guilty". If such is the case, then why aren't all the meat and egg eating mammals for the last million years, including humans, dropping dead of MIs and ischemic events?
Correlation is not causation.
