By now, you’ve probably heard the news about two recent research studies strongly linking a compound called TMAO to heart disease and stroke. After all, Dr. Oz covered it, so it’s got to be big news.
Here’s the basics:
- Two dietary compounds L-carnitine and phosphatidylcholine (we’ll cover diet sources later) get converted by bacteria in the gut to TMA.
- TMA heads to the liver where it is further converted by an enzyme called FMO3 to TMAO.
- TMAO has been strongly linked to heart disease and stroke irrespective of other, more widely known, risk factors.
L-carnitine comes from a few notorious sources. Red meat. Energy drinks boasting high levels of L-carnitine. Bodybuilding supplements.
Phoshotidylcholine is founds in eggs and beef liver (just in case you eat this on a regular basis…).
While some articles are blowing off the results of this study, I think that we need to look at this data as real, and try to figure out why and how it may occur. Overall, the results in these two particular studies (New England Journal of Medicine, Nature Medicine) should raise some eyebrows. Here’s what they found:
- Those with the highest levels of TMAO had a 254% overall increased risk of having a heart attack, stroke or dying.
- The risk of dying in the highest TMAO group was an impressive 337% higher.
- This risk was present even after accounting for traditional risk factors as well as in those patients who were considered low-risk.
Now here’s where the story gets a little more interesting…
- In one of the studies, participants were given antibiotics. The antibiotics almost completely shut down the production of TMAO.
- Once the antibiotics were stopped, the TMAO levels increased again.
- In vegetarians and vegans, the levels of TMAO remained low despite increased intake of phosphatidylcholine or L-carnitine.
Clearly, the bacterial flora in the gut had an incredibly strong role in whether or not these dietary components caused problems or not.
Gee…have we heard this somewhere before?
Have you maybe heard someone say that destruction of the normal flora in the human body is a potentially devastating event, especially in a child? Like…maybe me??
There is a well accepted concept that the bacterial flora in the gut adapts to a particular lifestyle. Women in Asian countries with higher intakes of soy have higher equol-producing bacteria in their gut and thus, derive greater benefits from eating soy than do their American-born, non-soy-eating counterparts. Could this be yet another example of how the bacterial flora in vegetarians adapt to that lifestyle, lowering the risk of disease?
Further, could our country’s love of antibiotics for minor sniffles be destroying the delicate balance of the bacteria in our gut, leading to chronic disease? Multiple lines of research suggest this is a solid answer.
So what is the bottom line? Of course, avoiding energy drinks and limiting red meat intake was already on your list. While these studies did not identify specific bacteria that were responsible for the conversion, they generally fall under the category of methylotrophic bacteria. These are NOT generally the types of bacteria found in probiotic supplements. It would seem likely that the use of probiotics would lead to less of the bacteria that leads to the conversion of these dietary compounds to TMA.