carnitine in meat and energy drinks
Carnitine in Meat and Energy Drinks

This week a study from the Mayo Clinic shows that giving carnitine 
to people who have just had a heart attack is associated with fewer 
deaths or irregular heartbeats, and less chest pain (Mayo Clinic 
Proceedings, published online April 12, 2013). Carnitine is found 
in meat and many energy and sports supplements and drinks.

Last week, a study from the Cleveland Clinic showed that carnitine 
can be converted in the intestines to TMAO, a chemical that causes 
heart attacks by punching holes in arteries to cause plaques to form 
in them (Nature Medicine, published online April, 2013).

No Conflict 
No conflict exists between the two studies. One shows that taking 
carnitine causes a specific type of bacteria in the intestines to 
convert carnitine to TMAO, which may increase risk for a future 
heart attack. The other study shows that carnitine can help to 
repair heart muscle damaged by a heart attack.

Athletes have known for many years that carnitine helps to clear 
breakdown products of metabolism from accumulating in skeletal 
muscles to delay recovery, so they take carnitine to help their 
skeletal muscles heal faster from hard exercise. In a like manner, 
carnitine may help heart muscle to heal faster when it is damaged 
by a heart attack.

This Week's Study 
The authors reviewed 13 controlled trials of carnitine given to 
3,629 heart attack patients. They had 250 deaths, 220 cases of 
new heart failure, and 38 recurrent heart attacks. Carnitine was 
associated with:
27 percent reduction in sudden death, 
65 percent reduction in irregular heartbeats (ventricular arrythmia),
40 percent reduction in the development of chest pain (angina),
reduction in size of the part of the heart muscle that is damaged 
(infarct size).

How Could Carnitine Treat a Heart Attack? 
When heart muscle is deprived of oxygen during a heart attack, 
toxic fatty acids accumulate in the dying muscle tissue to cause 
further damage, and carnitine levels drop precipitously. Carnitine 
helps to move these fatty acids into the mitochondria where they 
can be burned for energy. This helps to increase the circulation 
of blood, which increases oxygen supply to the oxygen-starved, 
damaged part of the heart muscle.

My Recommendations 
Since research data show that eating red meat is associated with 
increased risk for heart attacks, I believe that you should restrict 
your intake of red meat. I also feel that you are probably better 
off not taking supplements or energy drinks that contain carnitine. 
We have data that carnitine can be converted to TMAO by bacteria in 
your intestines, and TMAO can damage arteries to increase risk for 
a heart attack. If you have the misfortune to suffer a heart attack, 
your treatment may include taking carnitine to help repair the damage.