Carnitine, found naturally in red meat and not-so-naturally in a wide range of popular dietary supplements, has been linked to atherosclerosis, the deadly disease popularly known as “hardening of the arteries.” A disturbing study from doctors at Cleveland Clinic and elsewhere, published Sunday in Nature Medicine, has tracked the way that gut bacteria metabolizes L-carnitine. The researchers proved that when the bacteria digest the carnitine, they produce a waste product called trimethylamine-N-oxide (TMAO).
The jaw-breaking name of the chemical is bad enough. But the real problem is that TMAO promotes hardening of the arteries.
Because carnitine is naturally found in red meat, then it suddenly makes sense that omnivores have a higher rate of the disease than vegans or vegetarians. The researchers looked at mice and people who ate the different diets, and they found that people who ate meat also had more TMAO in their system. A review of the records of almost 2,600 patients showed that the higher the level of TMAO in their bloodstream, the more likely they were to have a heart attack or stroke.
Believe you me, I’m as disappointed as you are.
According to a Wall Street Journal interview with the study’s lead author, Dr. Stanley Hazan, there’s no good reason to add extra carnitine to the diet. In fact, he feels that it might be dangerous to consume more than you would eat naturally. The trouble is, l-carnitine has become a popular supplement because it’s believed to give energy and enhance a body-building routine.
About 250 milligrams of carnitine is found in an average serving of an energy drink — roughly the same or a tad more than an eight ounce steak. What if you drink one, two, or more energy drinks a day on top of a normal meat-eating diet?
“I worry about what happens in 10, 20 or 30 years of consumption,” Hazen said.
I was only a dabbler with weights anyway, but I’m glad I went back to coffee for my preferred energy drink. In light of the new research, you may want to re-consider if you’re using carnitine.
[red meat photo by Ewan Munro via Wikipedia Commons]