Effects of Choline From Eggs vs. Supplements on the Generation of TMAO in Humans

NCT ID: NCT03039023

Last Updated: 2025-11-04

Study Results

Results available

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Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

86 participants

Study Classification

INTERVENTIONAL

Study Start Date

2016-09-02

Study Completion Date

2020-09-03

Brief Summary

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The investigators are interested in learning more about choline, a nutrient required by the body. The body does make some choline, but it does not make enough to support health and the rest must be acquired through diet. Eggs, and especially egg yolks, are a major dietary source of choline. Choline can also be given as a dietary supplement. Ingestion of choline supplements has been linked to an increased concentration of a compound called TMAO (trimethylamine N-oxide). Elevated TMAO levels have been linked to higher heart disease risk. With this study, the investigators hope to learn whether there is a difference in the way your body responds to the ingestion of a choline supplement versus the choline found within eggs.

Detailed Description

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The principal goal for the study is to examine whether there is a difference between the ingestion of choline through supplements versus choline found within eggs on plasma TMAO levels. The investigators have previously shown that dietary intake of trimethylamines, including the choline group of phosphatidylcholine (PC), is mechanistically linked to cardiovascular disease risk and that the metabolism of these trimethylamine nutrients in humans is modulated by the intestinal microbes (gut microbes). Additionally, extensive animal studies link an essential role of gut microbiota to the metabolism of choline and the production of metabolites that promote / accelerate atherosclerotic processes. The investigators have also recently shown a 10-fold increase in plasma TMAO levels following supplementation with choline bitartrate supplements. However, another pilot study by a collaborator (unpublished) did not show the same increase in plasma TMAO levels following the ingestion of whole eggs, a major dietary source of choline. Therefore, with this study the investigators wish to examine the differences, if any, between the ingestion of an equivalent mass of total choline in the free form (as bitartrate salt) as a supplement vs. within whole eggs.

Eggs, and specifically the egg yolk, contain a large amount of total choline. However, egg white contains potential anti-microbial peptides that could influence gut microbial composition and function, and therefore impact conversion of choline into TMA and TMAO observed in subjects. Therefore, the investigators hypothesize that the consumption of whole eggs (hardboiled) will not elevate plasma TMAO levels to the same extent as a comparable amount of total choline ingested in capsule form as the choline bitartrate salt. The investigators further hypothesize that the consumption of egg white with choline bitartrate tablets may result in less of a rise in TMAO levels than ingestion of the choline bitartrate supplement alone.

Conditions

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Cardiovascular Risk Factor

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

NONE

Study Groups

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Whole Hardboiled Eggs

Subjects will consume four (4) pre-cooked, pre-peeled whole hardboiled eggs per day for 28 days.

Group Type EXPERIMENTAL

Pre-cooked, pre-peeled whole hardboiled eggs

Intervention Type OTHER

Obtained from a commercial source.

Choline Bitartrate Tablets

Subjects will consume two (2) 500mg choline bitartrate tablets per day for 28 days.

Group Type EXPERIMENTAL

Choline Bitartrate

Intervention Type DIETARY_SUPPLEMENT

500mg choline bitartrate tablets

Hardboiled Eggs + Choline Bitartrate Tablets

Subjects will consume both four (4) whole, pre-cooked, pre-peeled hardboiled eggs and two (2) 500mg choline bitartrate tablets per day for 28 days.

Group Type EXPERIMENTAL

Choline Bitartrate

Intervention Type DIETARY_SUPPLEMENT

500mg choline bitartrate tablets

Pre-cooked, pre-peeled whole hardboiled eggs

Intervention Type OTHER

Obtained from a commercial source.

Egg Whites + Choline Bitartrate Tablets

Subjects will consume both the egg whites (no yolks) of four (4) pre-cooked, pre-peeled hardboiled eggs and two (2) 500mg choline bitartrate tablets per day for 28 days.

Group Type EXPERIMENTAL

Choline Bitartrate

Intervention Type DIETARY_SUPPLEMENT

500mg choline bitartrate tablets

Egg whites from pre-cooked, pre-peeled hardboiled eggs

Intervention Type OTHER

Egg whites from pre-cooked, pre-peeled hardboiled eggs. The yolks are removed and discarded.

Phosphatidylcholine Capsules

Subjects will consume six (6) 420 mg phosphatidylcholine capsules by mouth per day for 28 days.

Group Type EXPERIMENTAL

Phosphatidylcholine capsules

Intervention Type DIETARY_SUPPLEMENT

420 mg phosphatidylcholine capsules obtained from a commercial source.

Interventions

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Choline Bitartrate

500mg choline bitartrate tablets

Intervention Type DIETARY_SUPPLEMENT

Pre-cooked, pre-peeled whole hardboiled eggs

Obtained from a commercial source.

Intervention Type OTHER

Egg whites from pre-cooked, pre-peeled hardboiled eggs

Egg whites from pre-cooked, pre-peeled hardboiled eggs. The yolks are removed and discarded.

Intervention Type OTHER

Phosphatidylcholine capsules

420 mg phosphatidylcholine capsules obtained from a commercial source.

Intervention Type DIETARY_SUPPLEMENT

Eligibility Criteria

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Inclusion Criteria

* Men and women age 18 years or above.
* Willing to remain on aspirin or stay off aspirin or aspirin products for 1 week prior to starting the study and throughout the study period.
* Able to provide informed consent and comply with study protocol.
* Able to be off all other supplements during the study period.

Exclusion Criteria

* Significant chronic illness.
* Active infection or received antibiotics within 1 month of study enrollment.
* Use of over-the-counter probiotic within the past month
* Chronic gastrointestinal disorders, such as ulcerative colitis or Crohn's disease.
* Allergy to eggs or lactose.
* Having undergone bariatric procedures or surgeries such as gastric banding or bypass.
* Pregnancy.
* Any condition that, in the judgment of the Investigator, would place a patient at undue risk by being enrolled in the trial or cause inability to comply with the trial.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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The Cleveland Clinic

OTHER

Sponsor Role lead

Responsible Party

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Wilson Tang

Staff, Cardiovascular Medicine, The Cleveland Clinic; Staff, Cellular and Molecular Medicine, The Cleveland Clinic Lerner Research Institute

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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W. H. Wilson Tang, MD

Role: PRINCIPAL_INVESTIGATOR

The Cleveland Clinic

Locations

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Cleveland Clinic Foundation

Cleveland, Ohio, United States

Site Status

Countries

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United States

References

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Wilcox J, Skye SM, Graham B, Zabell A, Li XS, Li L, Shelkay S, Fu X, Neale S, O'Laughlin C, Peterson K, Hazen SL, Tang WHW. Dietary Choline Supplements, but Not Eggs, Raise Fasting TMAO Levels in Participants with Normal Renal Function: A Randomized Clinical Trial. Am J Med. 2021 Sep;134(9):1160-1169.e3. doi: 10.1016/j.amjmed.2021.03.016. Epub 2021 Apr 17.

Reference Type DERIVED
PMID: 33872583 (View on PubMed)

Bidulescu A, Chambless LE, Siega-Riz AM, Zeisel SH, Heiss G. Repeatability and measurement error in the assessment of choline and betaine dietary intake: the Atherosclerosis Risk in Communities (ARIC) study. Nutr J. 2009 Feb 20;8:14. doi: 10.1186/1475-2891-8-14.

Reference Type BACKGROUND
PMID: 19232103 (View on PubMed)

Wang Z, Klipfell E, Bennett BJ, Koeth R, Levison BS, Dugar B, Feldstein AE, Britt EB, Fu X, Chung YM, Wu Y, Schauer P, Smith JD, Allayee H, Tang WH, DiDonato JA, Lusis AJ, Hazen SL. Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease. Nature. 2011 Apr 7;472(7341):57-63. doi: 10.1038/nature09922.

Reference Type BACKGROUND
PMID: 21475195 (View on PubMed)

Rebouche CJ, Chenard CA. Metabolic fate of dietary carnitine in human adults: identification and quantification of urinary and fecal metabolites. J Nutr. 1991 Apr;121(4):539-46. doi: 10.1093/jn/121.4.539.

Reference Type BACKGROUND
PMID: 2007906 (View on PubMed)

Provided Documents

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Document Type: Study Protocol and Statistical Analysis Plan

View Document

Related Links

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https://data.nal.usda.gov/system/files/Choln02.pdf

Patterson K, Bhagwat S, Williams J, Howe J, and Holden J. USDA Database for the Choline Content of Common Foods, Release Two. January 2008.

Other Identifiers

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16-1048

Identifier Type: -

Identifier Source: org_study_id

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