The researchers showed that eating two hard-boiled eggs (which contain about 500 mg of total choline) temporarily raised TMAO blood plasma levels, on average, from about 4 µM (micromoles) to close to 8 µM.
The data suggest that excessive routine consumption of dietary phosphatidylcholine and choline should be avoided. This may be advisable anyhow, as foods rich in these compounds (egg yolk, liver, beef, and pork) are also typically high in fat and cholesterol. The researchers note that a vegetarian or high-fiber diet can reduce total choline intake. Unless medically necessary, it may also be prudent to avoid long-term supplementation with high doses of lecithin, phosphatidylcholine, and/or choline.
(A similar connection with TMAO and cardiovascular disease risk was recently made by the same researchers for L-carnitine from red meat and, possibly, from supplements with L-carnitine, including acetyl-L-carnitine -- see the Concerns and Cautions section of the Acetyl-L-Carnitine Supplements Review>>).