In April, The Cleveland Clinic published studies pointing a finger at a new hazardous chemical naturally found in red meat: Trimethylamine-N-oxide, or TMAO. TMAO is the byproduct of carnitine digestion. Carnitine is a nutrient that fuels the cells that contribute to the replication of new cells throughout the body, primarily muscle tissue. In both animals and humans, when carnitine is ingested, microbes in the intestines break down the carnitine and convert it into TMAO, which turns out to be the trouble-maker.The Cleveland Clinic's Lerner Research Institute theorizes that excess amounts of carnitine ingestion leads to accelerated atherosclerosis (hardening of the arteries).
The everyday diet can effect the amount of TMAO the gut microbes make. People who eat large amounts of meat on a regular basis produce exponential amounts of the damaging compound. Vegetarians produce none of the compound, and people who had taken oral antibiotics for other ailments, yet ate moderate amounts of red meat, temporarily produced none. It shows that the amount of natural microflora in the gut effects how much TMAO gets produced. It is believed then, that by ingesting small amounts of red meat on occasion, the production is greatly reduced, because the bacteria strain has a chance to "die off" between the culprit meals.
To make matters worse, the TMAO was found to accelerate the deposit of cholesterol on the artery walls, and the liver was found to produce fewer bile acids, which aid in removing cholesterol from the blood and depositing them into the gut, where they are shuttled out of the body. The LDL cholesterol threat is raised on all fronts.
Although carnitine is a necessary nutrient, it is found in just about everything, so deficiencies in this country are extremely rare. Unless you have a mitochondrial disorder and are under doctor's care, throw out the carnitine & choline supplements. Limit your red meats to one serving a week. How much is a serving? 3 ounces. Not much, when you consider the average steak is 14 - 16 oz. The Panera Smoked Ham & Swiss sandwich contains 4 servings of meat. The average burger joint serves up 3 servings in one sandwich.
Reducing consumption is no easy task, but it can be done by keeping conscientious of your intake. According to Walter Willet, chair of the dept. of nutrition at the Harvard School of Public Health, "eating meat only once a week can eliminate most of the risk."