If like me, you enjoy cutting-edge science, you may enjoy the publication in Nature Medicine (doi:10.1038/nm.3145) by Robert A. Koeth et.al. just published on line on April 7, 2013. If science is not your thing, but you do like to know what’s happening in science, I’ll translate the results into non-scientific terminology. Knowing the gist of this study is really worth your time!

The reason I think this is such interesting research is that scientists at the many of the major schools of public health, nutrition departments, have been finding in their epidemiologic studies for quite a long time, that red meat increases risk of cancers, stroke, and coronary heart disease. But the cause or causes, has not been known for sure. Certainly, it has been postulated for a long time that saturated fat and cholesterol were the villains. Many of the public health researchers have written that they believe there is something damaging in red meat in addition to saturated fat and cholesterol, but didn’t know what that factor was. Identifying that unknown factor or factors is why this comprehensive study may prove to be so important to public health.

Dr. Stanley L. Hazen, M.D., Ph.D. who holds two endowed chairs at the Cleveland Clinic and is the Director, of the Center for Cardiovascular Diagnostics & Prevention and the Section Head, of Preventive Cardiology & Rehabilitation led this well-designed and fascinating study.

What Hazen and his group postulated was that cholesterol and saturated fat made only a minor contribution to the increased heart disease seen in red-meat eaters. The real problem apparently is a product produced by the bacteria living in the intestines of people who eat red meat. Here is how it flows: The individual consumes red meat, which is very high in carnitine. The carnitine is digested by the bacteria in the intestine and then that metabolite is converted in the liver to a chemical called TMAO (trimethylamine N-oxide). The TMAO gets into the blood and increases the risk of heart disease.

Note: red meats are beef, pork, lamb, duck and venison. Besides red meat, carnitine is found in fish, chicken, turkey and dairy products, but in smaller amounts.

When vegans (who ate no animal products for at least a year) ate steak, there was no boost of TAMO, two hours later, like the steak eaters. The hypothesis is that the vegans don’t have the same gut bacteria that the meat eaters have; those bacteria are necessary to make TMAO. So the persistent diet pattern has an important effect on the intestinal flora composition and our ability to make TMAO. If you want to limit your ability to make TMAO, then don’t eat meat frequently and don’t take energy supplements containing L-carnitine or even supplements with ‘energy blend’ on their ingredient list. ‘Energy blend’  is just a term which (like many other labeling ploys used by food processors) serves to disguise the presence of carnitine supplements.

The link of TMAO and heart disease was discovered in 2011. In those studies TMAO was fount to be a 10-fold stronger predictor of heart disease than cholesterol and that research has been validated in more recent work. In the latest study, the researchers followed 2,500 people to see if TMAO predicted heart attacks; and it did. The theory is that TMAO enables both cholesterol getting into artery walls and also prevents the body from excreting excess cholesterol.

The extra big scary snag with this discovery is that carnitine is added to many energy drinks and supplements. The amount of added carnitine in many energy drinks is equivalent to a porterhouse steak, or more. This is a red flag, OK two red flags!  With the skyrocketing use of energy drinks, energy pills and even some weight-loss treatments it behooves us to become a label reader if we’re going to use those products.

What bothers me most is that so many young people are drinking/taking the energy products and are likely not reading this type of blog. They won’t have a clue that they may be prematurely clogging their arteries and heart. I hate it!!!

Presently, tests are being developed, to be used in assessing heart disease risk by looking for TMAO in the blood.

The New York Times reported that Lora Hooper, an associate professor of immunology and microbiology at the University of Texas Southwestern Medical Center, who follows the Paleo diet, which is heavy on meat, to have exclaimed, “Yikes!”

The New York Times also reported that Dr. Hazen said that he used to eat about 12 ounces of red meat several times a week; and now, he eats it once every two weeks and has no more than a 4 to 6 ounce piece at a time. He says, that he’s not a vegan and likes a good steak. So for the rest of us it makes sense, (if we have not already done so) to eat red meat in moderation, even if your cholesterol is well controlled.

As with so many new discoveries, it will take much more research and many more studies to answer all the questions. But this exceedingly well-done study may motivate you to be careful with red meat and with energy drinks or dietary supplements containing L-carnitine.

If you want to read some of our other articles on red meat, you can choose from a list; or read one of our latest articles called More Bad News for Red Meat.