- Choline, a nutrient commonly found in animal products like egg yolks and beef, can increase production of the chemical TMAO in the body, which potentially increases blood clotting and the risk of cardiovascular disease.
- A study noted a tenfold increase in TMAO levels and an increased platelet aggregation, a step for blood clotting, in participants after they were given choline supplements for one month.
- Diet plans rich in plant-based foods, such as the Mediterranean diet, and possibly low-dose aspirin, were suggested as preventive measures due to their potential in reducing TMAO formation.
- The study suggests a link between the gut’s “microbiome”, the bacteria living in our digestive system, and cardiovascular disease. This poses the possibility of using beneficial bacteria, or probiotics, as a treatment for those at high risk of heart disease or stroke in the future.
- While the study is promising, it is still preliminary and needs to be confirmed with larger clinical trials.
A recently conducted study has suggested a controversial link between a regularly consumed nutrient found in meat and eggs, and an increased tendency towards blood clotting. This nutrient is identified as choline.
In a research experiment involving 18 healthy individuals, choline supplements were introduced to their daily diet. The supplements resulted in an elevated production of a specific chemical known as TMAO, or Trimethylamine N-oxide, which in turn impacted the participants’ blood cells, making them more susceptible to clotting.
What is TMAO?
Choline, when digested by gut bacteria, contributes to the production of TMAO. Previous studies have provided evidence linking elevated levels of TMAO in the bloodstream, increasing the risks of blood clots, heart attacks, and strokes.
Choline and TMAO’s Role in Platelet Aggregation
Dr. Stanley Hazen, the lead researcher in this study, has suggested that these findings are the first direct evidence that choline increases TMAO production in the human gut. This then encourages platelets, a type of blood cell, to become sticky, thus increasing the likelihood of clotting.
Choline is found in a variety of foods, most abundantly in animal productions including egg yolks, beef, and chicken.
A key objective of this investigation, led by Hazen and his team from the Cleveland Clinic, was to understand the effects of choline on TMAO levels and platelet function in human beings. The participants, a mix of meat eaters and vegetarians/vegans, were given choline supplements for two months.
After one month, an increase in TMAO levels by approximately ten times was seen in the participants. Blood samples showed that their platelets had become more clot-prone.
Implications for Cardiovascular Disease
“This research seems to shed light on one of the ways in which TMAO might contribute to cardiovascular disease,” noted Dr. J. David Spence, who was not involved in the current study, but is the director of the Stroke Prevention and Atherosclerosis Research Centre at Western University in London, Ontario, Canada.
While the increase in TMAO caused by choline may not be a cause of concern for the healthy individuals in this study, it may pose a risk for those at a higher risk of heart disease or stroke, asserts Spence. He prescribes limiting high choline foods such as egg yolks and beef.
Alternative Food Options and Prevention
Hazen echoes Spence’s advice and encourages a diet with more plant-based foods and vegetarian meals. Furthermore, he cites the Mediterranean diet, rich in olive oil, vegetables, and fish, as a potential alternative. His team also found an element in olive oil that seemed to inhibit the formation of TMAO.
Another substance discovered that could counter TMAO is low-dose aspirin. In a different experiment within the study, participants took an 85 milligrams aspirin daily along with the choline supplements. The aspirin seemed to limit the increase in TMAO and the changes in platelet activity.
Hazen suggests that aspirin’s effect on TMAO might be one of the reasons it aids in staving off cardiovascular issues.
Future Research and the Role of the Gut “Microbiome”
While this study is preliminary and comprised of a small sample, it contributes to a growing body of research that suggests that our gut’s “microbiome”, the vast population of bacteria within our digestive system, has a significant role in cardiovascular disease. We are just beginning to understand how gut bacteria and their byproducts impact our cardiovascular system, and moving forward it is hoped that we can identify a balance of gut bacteria that foster cardiovascular health.
This could potentially allow us to employ probiotic supplements, which are beneficial bacteria, as treatment options for people with high risk of heart disease or stroke, adds Spence.
Dr. Hazen notes that while heart disease risk can be attributed to a myriad of factors, the gut microbiome does play a part. “We suggest that a portion of the risk of heart diseases can be traced back to the gut microbiome,” he says.
This study can be found in the online issue of Circulation, dated April 25.
The American Heart Association provides further insight on heart-healthy eating. Click here for more information on the subject.