Lecithin: Friend, Foe or Neutral

I received several questions about Lecithin on Facebook and this blog after my last post on Emulsifiers. I cited one study that I found for illustration purposes:

Dietary carnitine (present predominately in red meat) and lecithin (phosphatidyl choline) are shown to be metabolized by gut microbes to trimethylamine (TMA), which in turn is metabolized by liver flavin monoxygenases (especially FMO3 and FMO1) to form trimethylamine-N-oxide (TMAO). High levels of TMAO in the blood strongly correlate with cardiovascular disease and associated acute clinical events.

Dietary modification of the microbiome affects risk for cardiovascular disease.[2013]

Many of the questions came from the belief that lecithin helps heal the gut. My goal is to see what has been found in studies listed on PubMed – my gold standard for separating urban-(medical)-legend from reasonable facts. I first look at conditions: There was nothing for Chronic Fatigue Syndrome.

Irritable Bowel Syndrome

There are no studies except with boswellia where it was used as a delivery mechanism.

Crohn’s Disease

“The most promising approach in UC seems to be the use of probiotics or the natural compound lecithin as a stabilizer of mucus structure to enhance the barrier…. ongoing phase III study … “

Improvement of a ‘Leaky’ Intestinal Barrier. [2017]

Note: that we have an “or” and “seems to be” — so no concrete results yet.

“Children with CD frequently consume food additives, and the impact on disease course needs further study. ( Mean exposures per day for xanthan gum was 0.96 ± 0.72, carrageenan 0.58 ± 0.63, maltodextrin 0.95 ± 0.77, and soy lecithin 0.90 ± 0.74.  )”

Children with Crohn‘s Disease Frequently Consume Select Food Additives. [2018]

Note: The authors are stating concerns about all of these food additives for Crohn’s Disease children

Ulcerative Colitis

In randomized controlled studies, delayed-release lecithin [phosphatidylcholine (PC)]  was proven to be clinically and endoscopically effective, which now awaits a phase III authority approval trial.

Lecithin as a therapeutic agent in ulcerative colitis. [2013]

Note: There were no results published for the phrase III study. If there are old studies indicating positive results and plans for more studies, but nothing is published, THEN most researchers would conclude that no positive results were obtained and thus the study was not published because it failed to produce intended results.

Issues Associated with Lecithin

 lecithin, choline, and carnitine) are converted by closely related gut bacterial TMA lyases to TMA, which is absorbed and converted predominantly by flavin mono-oxygenase 3 to the toxic trimethylamine N-oxide (TMAO). TMAO causes atherosclerosis in animals and is elevated in patients with coronary heart disease

New Insight into the Dietary Cause of Atherosclerosis: Implications for Pharmacology. [2016]

 No scientifically valid clinical studies exist on the safety and efficacy of high-dose lecithin supplementation in nursing mothers or infants. 

Lecithin. Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US)

Bottom Line

It appears that some early studies saw improvement when a delayed- release dosage of lecithin was used (no information on the dosage). As these studies were on what appear to be a potential commercial product, the missing phrase III studies suggest that positive results were not found. What is more interesting to infer is the decision to use delayed release — it implies there were issues seen with direct lecithin (which likely were not published but known to the researchers).

There are reports of lecithin overdose and drug interference. There are no safety studies to determine what dosage is beneficial (and what level is harmful).

I conclude that current published evidence does not support the use of lecithin supplements.