Monday, April 08, 2013

Will this get you to cut back on red meat?

A compound abundant in red meat and added as a supplement to popular energy drinks has been found to promote atherosclerosis, according to Cleveland Clinic research published online this week in the journal Nature Medicine.

The study shows that bacteria living in the human digestive tract metabolize the compound carnitine, turning it into trimethylamine-N-oxide (TMAO), a metabolite the researchers previously linked in a 2011 study to the promotion of atherosclerosis in humans. Further, the research finds that a diet high in carnitine promotes the growth of the bacteria that metabolize carnitine, compounding the problem by producing even more of the artery-clogging TMAO.

The study tested the carnitine and TMAO levels of omnivores, vegans and vegetarians. They also examined the cardiac effects of a carnitine-enhanced diet in normal mice compared to mice with suppressed levels of gut microbes, and discovered that TMAO alters cholesterol metabolism at multiple levels, explaining how it enhances atherosclerosis.
The researchers found that increased carnitine levels in patients predicted increased risks for cardiovascular disease and major cardiac events like heart attack, stroke and death, but only in subjects with concurrently high TMAO levels. Additionally, they found specific gut microbe types in subjects associated with both plasma TMAO levels and dietary patterns, and that baseline TMAO levels were significantly lower among vegans and vegetarians than omnivores. 

Remarkably, vegans and vegetarians, even after consuming a large amount of carnitine, did not produce significant levels of the microbe product TMAO, whereas omnivores consuming the same amount of carnitine did.

Steve:  I am always amazed when the media, even with the reputation of the New York Times and Wall Street Journal, cover a study that was performed on six men and women and mice. If the study found that carnitine in red meat lowered cardiac risk in six men and women, do you think the media would give a second look?

Let's not get away from the obvious. Our gut bacteria, or what is now known as our microbiome, plays a very prominent role in our health. In fact, when we are able to map our microbiome, epigenome, and genome, and see how they all work together, we will really be onto something.

Do vegetarians and vegans have different microbiomes than omnivores? Most likely. Is one more beneficial than the other? The answer is we do not know. 

This study did not directly examine carnitine-rich energy drinks or carnitine supplements. That said, we could do without energy drinks. In our opinion, carnitine supplements, while safe, have failed more than helped in the few clients we know that have taken it. The only reason to take it supplementally is if you suspect or know genetically that you do not produce enough carnitine.

As far as carnitine being a bad thing, let's put it this way: carnitine turns fat into energy. Your body makes it in the liver and kidneys and stores it in the skeletal muscles, heart, brain, and sperm. So if your not into taking fat and turning it into energy, than take the next drug Big Pharma comes up with to block carnitine production.

Let's not just single out red meat. Let's also add dairy products, fish, poultry, tempeh, wheat, asparagus, avocados, and peanut butter to list of foods rich in carnitine.

We have discussed red meat ad nauseam. Consuming it, grass-fed twice weekly, is not only okay, but it is healthy, as long as it is cooked without charring :)

You know what the most interesting part of this study was for me? The researchers completely wiped away the gut bacteria of the five meat eaters with what??? An antibiotic. I don't think I have ever seen this method used in a study before. I wonder if they told these subjects that it would take a year, if ever, to achieve a balanced microbiome. 

Would you be surprised if Big Pharma came up with an OTC antibiotic that could be taken, like Lactaid, right before eating beef, so consumers can still eat it without the risk? 

Finally, a study published April 15th in Mayo Clinic Proceedings found that including L-carnitine among the other therapies given in the acute setting for heart attack appears to significantly cut all-cause mortality and lead to fewer angina symptoms and ventricular arrhythmias. This is in direct opposition of the Nature Medicine study.

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