Protect Your Heart, Limit Red Meat (Video)

Research unveils a ‘gut’ reason for eating less meat


Think twice before cutting into that juicy steak for dinner or downing an energy drink to get a late-afternoon buzz. And if you’re a regular “consumer,” you may want to rethink your diet completely.

Cleveland Clinic researchers found that when processed in the gut, carnitine (abundant in red meat and added to popular energy drinks) is metabolized to trimethylamine-N-oxide (TMAO), a compound linked to clogged arteries (atherosclerosis).

Watch to learn more about TMAO

Carnitine is not just in red meat; it is used in energy drinks and body building supplements.

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More meat, more risk

The more you indulge, the greater your risk, according to the research. That’s because bacteria living in the human digestive tract metabolize carnitine, turning it into an organic compound called trimethylalamine (TMA), which is rapidly converted to TMAO by the liver. A previous study dating back to 2011 has linked TMAO  to clogged arteries.

Meanwhile, a diet high in carnitine shifts our gut “biology” so meat eaters actually generate more TMAO and compound their risk of cardiovascular disease.

About the study

All this comes from a study at Cleveland Clinic led by Stanley Hazen, MD, PhD, Vice Chair of Translational Research for the Lerner Research Institute and Section Head of Preventive Cardiology & Rehabilitation.

The study compared carnitine and TMAO levels in omnivores, vegans and vegetarians. Carnitine levels were higher in omnivores. Those with meatless diets did not produce significant levels of TMAO. When Hazen’s team gave the meat eaters antibiotics to wipe out the gut bacteria, their levels of TMAO dropped, and no TMAO was made from ingested carnitine – therefore, they found that it is the gut bacteria that is required to produce the artery-clogging TMAO.

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An expert’s advice

Dr. Hazen says you don’t have to stop eating meat all together. His suggestion: “Limit that steak to an occasional treat, and make it a smaller portion, too.”

Also important to note: carnitine is not just in red meat; it is used in energy drinks and body building supplements.

Read about this breaking research in The New York Times or watch Dr. Hazen on NBC Nightly News.

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  • Hiller

    I watched this report with great interest on television. My questions would be:

    What is the history of the control group? How was the meat raised? How much was consumed?

    These questions are not to be contrary, but, being a chronic illness patient, I have found that I have better energy when I eat some red meat. So, I purchase and eat only lean, grass-fed and grass-finished beef. I only eat a 4 oz. or less portion with a high-vegetable meal. No sugar, only dairy being organic, no-fat Greek yogurt and no fats but coconut and olive oil. I also eat organic chicken and some fish. Plus no alcohol and no processed food, no GMO’s and 80% organic.

    Should I still be concerned? Or, is this focused on a group who does not eat in moderation or as with as much care?

  • Jeff Iversen
  • Curly

    What about L-Carnitine, 500 mg tablets once a day? Okay? Or discontinue?

    • The_Beating_Edge_Team

      You can read the study at Nature Medicine – . In the study – it was the l-carnitine that was the culprit that was linked to increased athereoclerosis. It was noted however that vegetarians produced less TMAO from l-carnitine than meat eaters in this study. More research is being done to provide more information around these questions. betsyRN

  • Christopher K. Young

    So am I also increasing my risk by taking probiotics?

    • The_Beating_Edge_Team

      This question has not been answered by this study. Dr. Hazen answered a similar question recently: “Is there evidence or is it likely that probiotics may also inhibit the production of intestinal bacteria that produce TMAO in the liver, thereby reducing the harmful effects of red meat consumption?”
      Dr. Hazen: We don’t have a probiotic that does this yet- of all we have screened – but we are hopeful, and pursuing finding a potential therapeutic approach to suppress TMAO production/ As of now – the best approach is cut back on animal products.