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Carnitine Makes Red Meat – and Energy Drinks – Lethal

Fascinating new study shows energy drinks containing carnitine can be as lethal as eating marbled red meat. While everyone has been blaming red meat marbling (read FAT) and cholesterol, it seems there is also something in red meat called carnitine that metabolizes into bad stuff when it hits your stomach. You can also watch a video on AOL EveryDay Health HERE.

By Amir Khan, Everyday Health Staff Writer

MONDAY, April 8, 2013 — Red meat is known to increase your risk for heart disease, but according to a new study, it’s not just the fat and cholesterol that’s the problem. Researchers found that a compound in red meat that’s also a common supplement in energy drinks may raise your risk for atherosclerosis — the hardening and clogging of the arteries, according to the study, and gut bacteria may be to blame.

Researchers from the Cleveland Clinic found that when gut bacteria metabolize the compound carnitine, they turn into trimethylamine-N-oxide (TMAO), which has been linked to atherosclerosis and heart disease. In addition, a diet high in carnitine stimulates the growth of more of that type of gut bacteria, creating a loop that can severely raise your risk, researchers said.

“The bacteria living in our digestive tracts are dictated by our long-term dietary patterns,” Stanley Hazen, M.D., Ph.D., study author and section head of preventive cardiology and rehabilitation in the Miller Family Heart and Vascular Institute at the Cleveland Clinic, said in a statement. “A diet high in carnitine actually shifts our gut microbe composition to those like carnitine, making meat eaters even more susceptible to forming TMAO and its artery-clogging effects.”

This process may explain why a vegetarian diet seems to have heart-health benefits, he added.

“Vegans and vegetarians have a significantly reduced capacity to synthesize TMAO from carnitine, which may explain the cardiovascular health benefits of these diets,” he said.

The researchers looked at the levels of carnitine and TMAO in 2,595 patients who were omnivores, vegans and vegetarians, and found that high levels of both carnitine and TMAO were predictors of heart disease and stroke. However, having high levels of only carnitine was not a predictor, indicating that the gut bacteria that metabolize the compound and turn it into TMAO may be to blame.

“This process is different in everyone, depending on the gut microbe metabolism of the individual,” Hazen said in a statement. “Carnitine metabolism suggests a new way to help explain why a diet rich in red meat promotes atherosclerosis.”

TMAO acts as an irritant, said Steven Zodkoy, DC, a nutrition specialist with the American Clinical Board of Nutritionist, which causes blood vessels to become inflamed and can lead to heart disease.

“If the blood vessels swell because of an irritiant, such as TMAO, and you combine that with high cholesterol, that’s where the heart disease is coming in,” he said.

In order to test how gut bacteria influenced heart disease risk, researchers fed carnitine to mice, and found that it doubled their risk of developing atherosclerosis. However, after the mice were given antibiotics designed to clear out their gut bacteria, a diet high in carnitine did not increase their risk.

Ultimately, researchers said the findings make it clear that red meat consumption should be limited, and that people taking carnitine supplements for a boost or drinking energy drinks containing it should stop.

“Carnitine is not an essential nutrient; our body naturally produces all we need,” Hazen said in the statement. “We need to examine the safety of chronically consuming carnitine supplements as we’ve shown that, under some conditions, it can foster the growth of bacteria that produce TMAO and potentially clog arteries.”

Zodkoy said it’s important for people to reduce their consumption of red meat in order to ward off heart disease.

“I’m a big fan of reducing red meat,” he said. “The proper portion is 4 ounces, but most people when they go out are getting a large 16-ounce steak. Red meat is an important part of the diet, but we overdo it.”

Last Updated: 04/08/2013 |

April 9, 2013 Posted by | Uncategorized | 1 Comment