Doctor's Note

It was such an honor to be on The Dr. Oz Show last week. It’s expected to air during sweeps week next month. I’ll announce the date on the Facebook page. 

The TMAO story is such a fascinating twist. It helps explain, for example, Harvard’s Meat and Mortality Studies. The role of the inflammatory “foam” cells (so-called because they’re so packed with cholesterol they look foamy under a microscope) affected by TMAO is explained in my video series that starts with Arterial Acne and Blocking the First Step of Heart Disease.

When I say we normally make all the carnitine we need, there’s a rare genetic inborn error of metabolism that affects as many as 1 in 40,000 births, which can result in a need for dietary carnitine. Learn more in my video When Meat Can Be a Lifesaver.

What does carnitine do? It’s involved in energy production in the mitochondria (“power plants”) in our cells. The enzyme that uses carnitine to help us burn fat, carnitine palmitoyl transferase, is actually upregulated by about 60% in those eating meat-free diets, which may help explain why those eating plant-based diets tend to be slimmer. More details in my video How to Upregulate Metabolism.

The prebiotic videos I feature are Fawning Over Flora and Boosting Good Bacteria in the Colon Without Probiotics, though other videos describing the beneficial products our friendly flora make from the plants we eat include:

And for another behind-the-curtain peek at the egg industry, see Eggs vs. Cigarettes in Atherosclerosis and Egg Industry Blind Spot.

For some context, please check out my associated blog posts: Avoid Carnitine and Lethicin SupplementsWhy Are Eggs Linked to Cancer Progression?, and Top 10 Most Popular Videos from 2013

If you haven’t yet, you can subscribe to my videos for free by clicking here.

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  • Plantstrongdoc

    And the answer is NOT to pollute the meat further with antibiotics in the hope of wiping the bad-meat-eating-bacteria out. Probably the next suggestion from the meat industriy…

    • Don’t give them any ideas! But it does make you wonder if, in a lot of these studies, they will need to start enterotyping the test subjects and the food contaminants to make sense of the data.

      • alphaa10

        Enterotyping seems logical enough, given Hazen was able to introduce a vegan (at least one-year of vegan diet) to the omnivore diet, and start TMA / TMAO production– but only after his GI tract had been populated with TMA-producing bacteria.

    • alphaa10

      Isolating human omnivores from TMA producing bacteria is most effectively done by adopting a vegan diet, one which does not feed the bacteria. TMAO is not the only risk factor in cardiovascular disease, only a major risk.

  • Brian Humphrey

    WOW!! I was all set to buy L-Carnitine supplements online! Thanks Dr.Greger!! What about about carnosine? I know it has documented affects againts AGE’s.

  • Brian Humphrey

    WOW!! I was all set to buy L-Carnitine supplements online! Thanks Dr.Greger!! What about about carnosine? I know it has documented affects againts AGE’s.

    • Ralph

      I’ve been taking carnitine and lecithin for several years- but today is the day I stop! I wonder how many of the 35 or so other supplements I take are harmful. From previous videos here, vitamins B-12 and D are okay, but I think I may not renew my subscription to Life Extension. By the way, instead of taking carnosine, you can take beta alanine which is much less expensive and produces carnosine in your body. Carnosine is broken down to beta alanine by your digestion anyway.

      • The only supplement I routinely recommend for patients is Vitamin B12. In my experience Life Extension can be a great way to get laboratory testing done. We used their services in the last Meals for Health program in the Berkeley/Oakland area. I avoid any other supplements unless a deficiency is documented. Unfortunately given the distribution of normal laboratory values in the normal population it is easy for medicine to change recommendations and to start recommending supplements or medications for people who are normal. If your Vitamin D level is low the best Rx is sunlight. Taking vitamin D supplement doesn’t improve the arterial system by the liberation of Nitrous Oxide from subcutaneous stores. Dr. Greger has yet to run a video on this subject… see the talk: Richard
        Weller: Could the sun be good for your heart? Of course their are times I recommend Vit D but very few.


        • There are times I recommend TEDTalks like this one. But lately, they’ve been scraping the bottom of the barrel with Taubes acolytes Attia and Teicholz.

        • Dan P

          How can we “test” for choline deficiency? If you have access to full articles what where the actual dietary levels measured that correlated to increased prostate cancer risk? I am nervous only getting 300-400 mg/day as an adult male. But supplementing to the AI also makes me nervous.

        • OzDr

          Did you make the viewers aware it is not all sources of Choline that does this? I read the paper awhile ago and while eggs and other sources do cause these bad symptoms of increased cancer risk and increased prostate lethal cancer risk, not all of them do, and it is vital for our memory. Just be aware of the source you get it from. Like CDP Choline does not have this negative effect.

        • Idiocrazy

          What about iodine supplement? There is nowhere close to enough iodine in a regular vegan diet to meet the recommendations. The added iodine to salt is just a drop in the ocean.

          • AllVegan

            it all depends on where you live and how much iodine is naturally in the soil. if you are concerned about it a blood test should be able to tell you whether you are getting enough. If you want to supplement I would suggest introducing a few sea vegetables like Kelp to your diet. However you can overdose on iodine as well so don’t go crazy.
            I agree that salt is not a good place to get your iodine from.

      • Polly Hattemer

        Beta alanine will reduce taurine. Taurine has a lot of healthy benefits. However, if you try taurine, start slow and give your body time to get used to it. Taurine will facilitate the removal of some toxins from cells. You don’t want a fast detox reaction.

  • rick

    Glad to hear you’re going to be on Dr. Oz. Not only will that help you to get the word and science out, but hopefully help with their fundraising!

    • VegAtHeart

      FYI: Dr. Greger’s appearance on Dr. Oz is available here.

      • Thea

        VegAtHeart: Thanks so much!! I’ve been wanting to see that clip and previous efforts to find it didn’t work. Much appreciated.

        • VegAtHeart

          You’re welcome!

      • Charzie

        Yeah, I was kind of surprised he didn’t take a more aggressive stance, but I guess he was either being diplomatic as to not alienate the audience, or the show had “policies” about what and how it was handled?

  • Sue Solin

    I saw something about this on CBS news earlier this week. INSTEAD of taking the opportunity to promote a plant-based diet they talked about drug companies hopefully being able to make a new drug to treat TMAO (insert face palm here). When are they going to figure this out. I wish HLN’s evening new show would include Dr. Greger several times a week. A reoccurring nutrition segment on national news would be wonderful and Dr. Greger keeps his information short and concise and throws in a little humor. It would be perfect for the masses!

  • Scott

    I am currently taking the more bio available Acetyl-L Carnitine as a supplement for some of the studies dealing with it’s protective qualities toward hearing loss. Being a 25 year low fat eating Vegan, can I assume that I am fairly safe from the TMAO production and it’s effects you are referring to?

  • Douglas McKee

    Don’t do this Michael. You are falling into the same trap they have.

    It is not the specific ingredients, either carnitine or lecithin, that is the problem. It is the gut flora that has developed in response to a refined ingredient and high sugar diet.

    Remember the 1875 patients were referred to their heart clinic because they already were really sick. Their gut flora was mainly firmicutes and some tenericutes, species that are not resident in a healthy gut flora.

    Restoring a healthy flora is the key here, not blaming highly processed ingredients that merely feed the bad bacteria. The liposaccharides from healthy flora does not raise TMA.

    Consuming polyphenols in veggies and fruits are the natural way to decrease firmicutes and support bacteroidetes and decrease heart disease. Antibiotics are not.

    • Yes, it’s more about the gut flora than isolated ingredients. Japan has one of the lowest rates of heart disease, South East and South Central Asia have the lowest rates of prostate cancer. They eat fish and eggs. But their gut bacteria is different to begin with. US microbiomes are more focused on degrading amino acids, while, for example, Malawian microbes are focused on digesting starches.

      • johnnywhite

        Very interesting …thanks for this post

    • elsie blanche

      Douglas, are you suggesting that meat consumption is not the culprit here? Thank you for more clarity on your previous comments.

      • My thought as well. Japanese eat lots of sugar. Meat, not so much. Sugar is likely an issue here in the US because of the lack of whole plant foods in the diet and the excess calories sugar contributes here. In other words, portion sizes count.

    • Dr Greger is in no way advocating the use of antibiotics to treat CVD. Antibiotics merely confirmed the hypothesis that gut bacteria were involved in the conversion of carnitine and lecithin to TMAO. Which bacteria involved has not yet been determined.

      By now, I think it can be safely stated that pretty much anything we put down our gullets affects the ecosystem in our digestive tract.

  • AileenO

    When are you on Dr. oz?

    • Thea

      AileenO: Friendly tip: Dr. Greger has a ‘Doctor’s Note’ under each of the videos. Above, you can see that Dr. Greger gives a link to a Facebook page where he will announce his Dr. Oz showing when he knows it. Hope that helps.

  • Farraday Newsome

    This was an awesome video Dr. Greger. Your research is so up-to-date and wide-reaching. Your presentation is engaging and succinct. Thank-you for this and so many excellent videos.

  • Guest

    I think you should not say compared to omnivores but compared to meat
    eaters or vegetarians. As it gives the false idea that people are
    omnivores when really we are herbivores. So really people are not
    omnivores but herbivores that eat meat. Just like Panda’s are carnivores
    that eat bamboo.

    • Guest2

      The similarity of our body design to that of the great apes make me wonder if we’re not actually frugavores. Apes eat mostly fruit and greens. Some eat grains- raw. Since we produce more amylase that most apes, it seems that we’re adapted to grains too. Chimps seem to be an exception. They also eat an occasional monkey, perhaps as a ritual to show dominance. Herbivores eat mostly grass, I’ve tried it in juice form once or twice (as wheat grass) and I find it to be disgusting. So, I’m afraid I wouldn’t make a good herbivore.

      • Kelly

        Frugivores…LOL! :)

    • Kelly

      Nonsense. Humans are omnivores, sheesh.

  • I think you should not say compared to omnivores but compared to meat eaters or vegetarians. As it gives the false idea that people are omnivores when really we are herbivores. So really people are not omnivores but herbivores that eat meat. Just like Panda’s are carnivores that eat bamboo…

  • I don’t know if I missed it but I didn’t catch any recommendations about Carnitine or Choline? And how much we need to get of both and or good sources in food? What do you recommend?

    • Toxins

      No need to seek these nutrients. Carnitine is produced by our own body and choline is available in a variety of plant foods in adequate amounts. Choline deficiency is quite rare in healthy populations.

      • Jessica

        I recently tracked my diet and found that I average 221 mg choline a day from plant sources, as opposed to the 400 mg RDA. Is there any reason I should work to boost intake from whole grains, beans, and peas?

        • Brandon Becker

          The USDA database doesn’t list choline for many foods, so it’s likely your choline intake is actually much higher than listed.

  • There’s a problem with this notion.

    Studies in humans have shown that neither phosphatidylcholine nor choline-rich foods produce detectable increases in trimethylamine.

    • With reference to your second citation, the major weakness I see in the Hazen studies at the heart of this video is that cold water fish can contain significantly greater TMAO than the carnitine content of red meat, yet fish consumption has a far weaker correlation with cardiovascular disease than red meat consumption.

      I suspect that red meat’s combination of numerous inflamatory hazards (carnitine/TMAO, saturated fat, cholesterol, endotoxins, AGEs, Neu5gc, heterocyclic amines, persistant organic pollutants, etc) acting in concert after every meal, and its lack of significant anti-inflammatory components like omega-3 fatty acids, may result in it being a particularly potent cause of cardiovascular disease. More so than any one of its components in isolation.

      Serum TMAO levels in a cohort of Western omnivores are very strongly correlated with cardiovascular risk (, but its also possible that that the TMAO is serving as a biomarker for consumption of a whole range of hazards, rather than a singular risk. At present, there aren’t any studies on other populations (ie. those on traditional Japanese diet) where serum TMAO may arise mostly from non-red meat sources.

      To tease out whether TMAO alone is a dominant cause of atherosclerosis in humans might require an impractical or unethical study like feeding Monster energy drinks (more carnitine than a Porterhouse steak) to vegans for an extended period.

      • Thea

        Darryl: re: “I suspect that red meat’s combination of numerous inflamatory hazards … acting in
        concert after every meal… More so than any
        one of its components in isolation.”

        That makes sense to me and is quite in line with the approach that is presented in the book The China Study. The idea is that we can work on understanding individual mechanisms on how things work, but diseases rarely operate on a single mechanism. It is the whole system that comes together to create effects. At least, that’s my understanding of the point of the book.

        Anyway, I was moved to reply to your statement, because literally hours before seeing this video, I had found what looks like the best recipe in the world for making vegan butter!!:
        BUT it has lecithin.

        I wouldn’t be using the vegan butter (fat/pure oil) all the time anyway. I am trying to go in a generally more healthy direction. But I still want the occasional treat and say butter on pancakes would be a real treat.

        Thus, the vegan butter idea was really exciting. This
        video raised the question in my head about how harmful the lecithin would be in the vegan butter. Which gets to your point: I’m hoping that by itself, as part of vegan butter in a vegan diet, that the lecithin wouldn’t be so bad – at least no more bad than any plant-based fat.

        That’s what I’m going with anyway, because when
        I get all of the ingredients, I’m going to give it a try. Thanks for posting your thoughts. You helped me put things into perspective.

    • Mr. Mooney, sorry, could you explain your use of first reference when it states, “A significant fraction of ingested choline is destroyed by enzymes within gut bacteria, forming trimethylamine”

  • and then there’s this:

    May 2011 Lecithin Supplements and Breast Cancer Risk

  • Deb P

    Very interesting. I have two questions.
    First, if vegans, not having the gut flora that produce TMAO, are somewhat protected, would not this same protection apply to eating eggs as well?
    Second, does it make any difference if the eggs come from pastured, naturally fed hens?

    • Plantstrongdoc

      Nope – eggs are eggs. Some come from happy chickens, some from battery chickens and some come from organic chickens (which BTW can be battery chickens), but the composition of the egg is similar. If you are lucky – a little less dioxin….

    • b00mer

      I could be misunderstanding your question, but eating eggs regularly will change your gut flora. You will no longer have the gut flora of a vegan i.e. you would no longer be a “protected” vegan.

  • Guest

    Hi, Dr Greger. Does this means we have to stay away from cauliflower, almond, and peanuts too? Last time I check 100g of cauliflower contains 45.2mg of choline. That’s close to 1/2 of an egg.

    • My guess is that further studies will be completed on choline and we will have a better picture of it’s effects on intestinal microflora. My experience is that most egg based entrees, use 2 to 4 eggs per serving. So some people are consuming a lot of choline and quite frequently. Compounds in cauliflower (like glucosinolates) have an anti-cancer effect and are cardio-protective. So I’m just avoiding eggs and keeping cruciferous vegetables on my plate and flax seeds in my smoothies…I’m not a huge fan of peanuts, I like the taste..however I think there are options with more nutrients.

  • prez

    Here’s the problem I have. The big issue with eggs seems to that the bacteria in the gut break down the lecithin in eggs and produce TMAO–which causes damage to the artery walls. Just this past week we saw the research promoting fenugreek as an herbal wonder which helps with everything from body building to sexual health. But fenugreek is high in lecithin. Why is the lecithin in fenugreek good for us and the lecithin in eggs a killer?

  • SG

    I assume egg whites are OK?

  • chas j

    I take 650 mg of betaine per meal for protein digestion. Does this pose a risk insofar as choline is converted into betaine? Is is that choline itself to excess is dangerous or is it the betaine as an end product?

  • Der Dr. Gregor,
    Outstanding video! I had totally missed the choline connection!
    It would be interesting to do some self experimentation by altering our diet in various ways for a few months and then testing our blood levels of TMAO, choline, & L carnitine, Do you know anything about the availability of blood tests for TMAO for the everyday person not in a research study? It would be interesting also to find out if supplementation with various kinds of probiotics and fiber might affect the proliferation of L-carnitine and choline metabolizing bacteria in people who do eat specific amounts of meat, and to answer the question of to what degree can competing bacteria reduce the populations of the L-carnitine & choline loving bacteria.
    Lastly, some of the other commenters raised some very good questions. We would love to hear your response to them. So far most of these questions have not been addressed.

    • Urine TMA/TMAO is a not uncommon test for the genetic disorder trimethylaminuria, where the ratio, rather than absolute levels, is important – you may need to confirm reporting if you want to experiment. A list of labs from around the world that will perform this test:

  • Karina

    I am so happy to see this video. I was vegetarian and now I am full vegan, but I kept wondering if I should supplement choline to get the brain boost. Now I know it is not necessary. Will you make a video about taurine in vegans? I saw in another video that taurine helps to protect against AGE’s. Thank you for these videos!

  • Why restrict your Dr Oz airdate announcement to Facebook? Some of us value out privacy too much to entrust it to Zuckerberg and Company. Please widen out your announcements to other communication channels.

    • Agreed. I rarely if ever venture into Facebook territory.

    • shaniqua

      Maybe Oprah will give Dr. Greger his own show on her network.

      • That might be tempting, though I’m not sure Dr Greger wants the commercial nature of show business to taint his message.

  • It boggles my brain cells why anyone would eat meat, drink milk, consume cheese and eggs once scientists are finding these links to diseases that are preventable just by NOT eating this stuff. Is it the same idea as when people smoke? They know it causes disease but keep doing it? I still cannot figure that one out, except for the addictive properties, but are some humans addicted to meat, milk, eggs and cheese or is it just an unfortunate quirk of our current society? Why don’t doctors just tell people to STOP eating stuff that causes disease? Are they afraid of the meat and dairy industry?

    • Plantstrongdoc

      When it comes to diet and disease most docorts are ignorants. I dont think they are afraid, they just dont know the abundance of science that backs up a whole food plant based diet. In the medical community you dont hear much about nutrition. My mother (type 2 diabetic) says that I am the only doctor ever, who has told her that she is to fat. The only one! I have heard about a GP who recommended more read meat to a patient, because she allegedly lacked proteins in the blod (the story made no sense)! I know a person who went to his doctor to get some help to loose weight, because he was just diagnosed with type 2 diabetes, and the doctor replyed “you are not overweight” – despite the obvious fact that the man was at least 20 kg overweight. I was actually searching for something else, but found informations about this topic by chance.

    • barbara parker

      so many rhetorical questions! here is my take as an informed consumer who didn’t know this stuff until seeing ‘Forks Over Knives’ despite ‘paying attention’ to nutrition for many years. ordinary people don’t know this stuff. Dr. Greger’s recent video on the McGovern Report was an eye-opener. doctors don’t know this stuff! there is very little attention paid to nutrition in medical school and the pharmaceutical industry ‘friends’ them after school. lastly, there is inertia, a HUGE factor in why people don’t change.

    • alphaa10

      Through its favorite, pliant congresspeople, the corporate food industry struggles feverishly to control not only consumer legislation but funding of nutritional research. Industry also perfects its many channels of access to public policy decisions through the revolving doors of EPA and Agriculture.

      That same congressional and agency influence serves industry well as an effective firewall against bad news from scientists. No scientist wants to create a profile of industry-perceived hostility, especially with FDA and Agriculture funding literally under the thumb of “former” executives from Monsanto, etc.

  • I’m vegan and took a 500 mg carnitine supplement for a few months to see if I felt any different. No difference at all. I did the same with 250 mg choline (and 250 mg inositol in the same pill) and also felt no difference. Seeing as now it may be harmful to use these supplements, I don’t plan on buying them again. What is your suggested intake of choline from food? What about carnitine, which I assume our body makes from eating foods high in lysine and methoinine?

    • Update: Before I saw this video I bought a small bottle of acetyl-l-carnitine to test out. I’ve taken acetyl-l-carnitine at the levels from 250 mg – 750 mg daily for the last 8 days and, unlike l-carnitine which I didn’t feel anything, the acetyl form makes me feel bad. It’s causing heart palpitations and I have no history of any heart problems. I’m stopping this now and dumping the rest of the bottle. I will go the safe (and free!) route of just eating food and having my body produce whatever carnitine is needed on it’s own.

  • Is choline present in egg whites, egg yolks, or both? Does eating just the egg whites have the same effect as eating a whole egg (in regards to choline)?

  • dr.jim

    Is that choline in the whites of the eggs also ?

  • I agree with all this and the wonderful and proven benefits of a plant based diet. However, a friend who follows Weston Price Fndn and Mercola sent me this link. Any comments?

    • b00mer

      Your link doesn’t appear to have worked; you’ve included the link to this video.

      Regarding Weston Price and Mercola, I would find it hard to critique either of them because they just can’t be taken seriously. In the blog world maybe, but in the world of peer-reviewed research, they’re just not considered legitimate sources. The few Mercola articles I’ve read, when I actually checked his sources, stated completely different conclusions than what he was peddling in his article. The Weston Price Foundation is based on the idea that we should ignore all of the clinical, epidemiological, and basic science research that has been done to date, and base our nutrition decisions on what a dentist from the 1920’s thought.

      However, if your friend has peer-reviewed modern research articles that they wish to share (since that is what this site is based on), I’m sure many would be happy to discuss them.

      • Psych MD

        I am posting here only because I searched in vein for a reference and found none. Dr. Greger, what is your opinion of coenzyme Q10 supplementation?

  • Carl Newmeyer
    • Gatherer

      Debunked by Chris Kresser, L.Ac (Licensed Acupuncturist)??!!

  • Carl Newmeyer
  • Christine T.

    Dr Gregor,
    Not to change the subject, I was wondering if and when you might discuss
    Chromium and linoleic acid. I would be interested in that topic.
    Thank you and I enjoy reading all your presented research online.

  • Wegan

    Does the last chart show eggs or radioactive lecithin?

  • foxfyr

    Please take a look at yet another study (“L-Carnitine in the Secondary Prevention of Cardiovascular Disease: Systematic Review and Meta-analysis”)

    Now, another study delivered by the Scarecrow from the Wizard of Oz delivers a study asserting that Carnitine, a compound found in red meats, appears to be cardioprotective in a systematic review — a finding that comes barely a week after a Nature Medicine study sounded an alarm about the heart risks of carnitine in the form of derivative TMAOs.

    OK….is this a case where the substance (LCar) itself is beneficial, but the by-products are not? Or…
    And if so, how does one balance or even evaluate the balance between the two effects.


    • Thanks for the question foxfyr! The study to which you’re referring can be found here.

      We’ve known for over 20 years ( that large doses of carnitine given intravenously in people within hours of a heart attack may have an antiarrhythmic effect, presumably by facilitating glucose oxidation in the failing heart muscle. Because it’s given directly into the bloodstream, it enters our body the way our own body creates it (bypassing the gut). Only when carnitine enters the gut could that toxic TMAO be made by the gut bacteria. In the context of a heart attack, even carnitine supplements given orally could help the patient live through that critical first post-MI period by lowering risk of ventricular arrythmia even if it might be contributing to further plaque progression elsewhere in the heart. Hopefully we will all never be placed in that situation by preventing the heart attack in the first place by decreasing our intake of carnitine, choline, cholesterol, saturated fat, and trans fats found in animal foods and junk. Check out my video series starting with Arterial Acne.

  • The Linus Pauling group and others are saying that the adequate itake of choline for adults is betwem 425 and 550 mg per day. That’s something like seven cups of flaxseed, peanuts or almonds, or two-plus pounds of coliflower. What does Dr. Greger recommend?



    Serving size:

  • Neal

    I just read in Healthy at 100 by John Robbins that he recommends L-Carnotine for vegans, and I started taking supplements, so I guess I should stop taking it??


  • Dave

    My question Is whether L-Carnitine HCI, 500 mg is safe to to take?

  • abeleehane

    I don’t want to be a pest, but people refer me to Weston Price inst. analysis(Chris Masterjohn) of the studies above. I don;t have the tools or knowledge to refute any of it. I was wondering if there was any data pertaining to this “rebuttal”
    I personally can’t take the Weston Price Institute seriously, but Mr Chris Masterjohn seems to have a following, and giving it a flick and wishing it away doesn’t seem responsible.

    • Thea

      abeleehane: Perhaps this will help you: Plant Positive on You Tube has several videos that competently address several of the problems with Weston Price information. I would guess that there are also other sources of information refuting what Price sells as good science. I just haven’t bothered to look further myself.

      Here’s one link that will get you started:

      Plant Positive posts a series of videos. The above link is just to one of video in the series. If you (or others you want to educate) are interested, I recommend watching as much of the series as you can. Plant Positive addresses all sorts of claims by paleo and other types of diets.

      Good luck!

      • abeleehane

        Thank you very much, the videos seem to be well made and science based.

        • Dan Lundeen

          PlantPositive is an Excellent Resource! FWIW Dr. Greger wrote the book debunking low carber truthiness, titled Carbophobia, and you can get a copy free or at very low cost, check out Don’t expect Dr. G to go over everything again on this message board, and if you watch just a fraction of his 1600+ videos you’ll see he already has.

  • Emily

    Dr. Greger, thank you for this valuable information. It does, however, present a personal problem for me. I had been vegan for a few years but for some reason could not stop eating all day long. I believe this has to do with undiagnosed hypoglycemia. At any rate, I find that the only dish that fills me up and prevents me from grazing and experiencing massive food cravings is stir-fried brown rice, veggies, and eggs in the morning. I eat vegan food for the rest of the day. I have tried protein powders, nuts, tofu, beans, etc. and none of the vegan sources of protein have the blood-sugar leveling effect of the eggs and rice. Do you have any suggestions? Is there some magical combination of vegan foods I could eat in the morning that would help keep my blood sugar level throughout the day?

    • earnest

      Perhaps eating more foods that are high in fiber or water would help fill you up.

  • Aussie86

    Is a guy named Tim, might know him from his youtube channel Running Raw. Raw vegan and marathon runner. Great explanation about TMAO.

  • Interesting! Just curious – if, when vegans eat a steak it doesn’t increase their TMAO levels, because they lack the gut bacteria to metabolized carnitine or choline into TMAO – then why would vegans, who eat foods or take supplements containing choline, be at increased risk for heart disease and cancer due to TMAO’s?


    The Cleveland Clinic study that got this rolling was bogus,
    judging by a detailed, persuasive analysis from UCONN nutrition PhD candidate Chris Masterjohn:

  • Mark L.

    This study you cite has a number of serious flaws, and the connection between carnitine and heart disease is weak at best:

    Sometimes it’s best to examine the methodology of the research a bit closer as well as the results to see if all extraneous variables are accounted for. Instead, it appears you are agreeing with it’s conclusions prematurely as a result of your own particular bias on nutrition. Not that I don’t agree with the majority of your input, but in this particular case it is flawed.

  • Lissen Up

    These data raise good questions. More data need to address additional factors possibly associated with TMAO increases and then begin to narrow the correlates down to plausible causal factors. There are so many “maybe’s” and words like “plausible” and “presumably” in this article to have confidence in the conjectured causalities. No sense changing diet based on associational relationships alone. So many possible paradoxical effects to account for first.

  • Jonathan Ray

    Avoiding normal dietary choline would be going far beyond what the evidence in the cited studies can yet support.

  • Green Kolibri

    Dear Dr.Greger, thank you so much for all your interesting lectures and presentations. I enjoyed one at the SF Vegetarian Festival a week ago.
    Recently I came across this article where the author suggests (like some people were predicting that the reaction from those, who don’t want to part with animal products, and the industry, of course would be like it) that it might be factory farming toxins that are to blame for the TMAO producing bacteria not the meat and animal products themselves”.
    Since the body can be cleaned from any bacteria with the help of antibiotics, and it takes only 2 weeks to restore the intestinal flora – then it seems that it should not be difficult to check whether “clean” start with the “organic”, or non factory farm animal products would bring back the TMAO causing bacteria or not.

  • PQRider

    Dr, Greger,
    Would you please comment on the recent Mayo Clinic paper disagreeing with the conclusions of the Cleveland Clinic study.

  • RappFan

    You’ve pretty much demonized choline here without saying why the body needs choline, especially athletes who train heavily. While I’m not a vegan nor will I ever be one, I find your website helpful in balancing my diet and it has even led me to incorporate more veggies into it. Keep up the good work.

  • pb

    Is carnitine play a role in Huntington’s as a factor in mitochondrial transport ?

  • Gail Ann Shores

    Dr. Oz had a show on last week where he recommended CLA supplement of 1500 mg twice a day. I have bought at GNC and started taking now I read this article?? Should I discontinue?

    • Before following recommendations from TV shows such as Dr. Oz I would check out more reliable free websites such as NutritionFacts or Dr. John McDougall. I have not seen any credible science which shows that recommending for the general population to take CLA at 1500 mg twice a day is beneficial.

    • Evidence from randomized controlled trials (RCT), do not convincingly show that CLA intake produces clinically relevant effects on long-term body composition. (1) Moreover, there is some concern that taking conjugated linoleic acid may worsen diabetes.

      Martha Belury and her Ohio State research team
      “found that CLA supplementation significantly decreased body fat in the first group of mice, but at the same time excessive amounts of fat accumulated in the animals’ livers. Belury linked this accumulation of fat in the liver to increased insulin resistance.” (2)

      A healthy lifestyle and a whole food plant-based diet along with exercise is the only proven method for long-term weight loss and weight maintenance.


  • Gail Ann Shores

    Thank you Dr. Forrester and Dr. Sanchez for responding to me and so quickly!!

  • Max

    Would this include supplementary CDP-Choline (aka citicoline)?

  • Jerry Taylor

    is honey an animal protein and does it raise TMAO?

  • The Hearty Vegan

    This article made my Vegan Best of 2013 list! Thanks for all your research and expertise!

  • johnnywhite

    The gorilla in the room is “Probiotics”–these products mite change the entire “chemistry” of TMAO in the gut.

  • Buns

    This is all bad news for me. I eschew meat but take carnitine supplements because I have heart failure that entails a significantly enlarged heart. The carnitine has allowed me to go about normal everyday activities without having to stop to catch my breath and without pooling of blood in my feet. Are there any alternatives that would provide the same coronary benefits as the carnitine supplements?

  • Harald Illeditsch

    So what’s the deal with lecithin? Is it good or bad? And is there a difference between soy lecithin and sunflower lecithin?

  • Headache

    Thank you. Being a descendant of early American settlers, I now know it was not my ancestors that killed off the natives, it was the natives high meat consumption! :)

  • Achim

    I have two questions:
    1) the lecithin in eggs and TMAO – what about eating egg white only?
    2) avoiding Lecithin supplements: soy protein shakes do include Lecithin. Is this critical or is the dose so small that it does not really matter?

  • Achim

    Should read as
    1) Cholin in eggs and TMAO – what about eating egg white only?

  • cyndishisara

    Now this video obviously answers my question can we safely consume eggs by adding flax and or/ garlic. However, choline is so prevalent in the vegetable kingdom that it is impossible to avoid. Even with broccoli a pound (180 mg) the concentration is higher than 2 eggs as two eggs. Furthermore, betaine and choline are protective in control of homocysteine levels. This situation as it seems makes it hard to eat healthily. I do comprehend that vegans can handle a steak because their gut flora has already been transformed to non choline-phil. What about an occasional egg after our transformation? I sound like an egg glutton! Seriously, I have nothing against veganism however most of the world especially in colder climates consume a small percentage of their diet animal products.

  • Martin Van Lear

    this video is superb. my first thought was about phosphatidylserine (made from cow brains and soy beans) is sold in supplemental form to those with memory problems and to increase athletic performance. however, this research discusses phosphatidylcholine. yet when i researched the similarity between these two, it seems phophatidylcholine comes from the sames sources…i wonder if phosphatidylserine is bad for us as well??? gasp! anyone have any research or thoughts on this….if so please do share…thanks so much again dr. greger for this great presentation…

  • abstract

    Since Choline is a nutrient that is a precursor of the phosphatidylcholine and sphingomyelin, both major components of cell membranes and inadequate amounts can affect memory especially in an unborn developing fetus. What would you recommend as a suitable choline source?

  • Healthyself

    A friend told me that granulated lecithin cleaned the cholesterol off the artery walls. Is this wrong info and why?

    • Charzie

      Cool name…both “heal thyself” and “healthy self”…I love it!

  • UCBAlum

    This doesn’t make sense.

    So choline and carnitine are converted by TMAO by “animal product-consuming gut bacteria” but not by “fiber-consuming gut bacteria”. This is why vegans produced no TMAO in the study by meat eaters did.

    Therefore choline and carnitine are safe for vegans with respect to TMAO.

    Why the need to avoid not just all animal products but also lecithin and energy drinks? If someone eats vegan then they should be able to drink all the carnitine drinks and take all the choline supplements they want and produce no TMAO.


  • James Sloane

    In my opinion that really does not make sense for several reasons.

    of all as a fat emulsifier the lecithin is going to aid in the
    absorption of fats in the diet and in the process will be absorbed
    itself. Therefore little if any of the lecithin would reach the
    majority of the flora, which is in the colon.

    Secondly, bile is
    released in to the intestines all the time as part of the natural
    digestive process. Bile is about 80% lecithin, which is why bile is an
    emulsifier. So how does Greger explain this lecithin not interacting
    with these bacteria?

    Third, lecithin is a component of cell
    walls. So why don’t these bacteria use the lecithin from dead cells
    being excreted in the feces?

    Any why don’t more people have heart
    disease from the TMAO since these processes in which TMAO is being
    produced occur from the beginnings of life? If TMAO was such a danger we
    would have all died by the age of 5 from heart disease.

    sounds like one of those cases where someone is taking a little
    unverified information they read in a medical study and are blowing it
    out of proportion by ignoring things such as the body’s ability to deal
    with certain harmful substances.

    For example, someone could read
    some medical journal article on how cyanide can kill you and then
    exaggerate the claim that the cyanide found in the seeds of some foods
    will kill you if you ingest them overlooking the fact that we also
    produce an enzyme that convert this cyanide in to a harmless

    So I am not going to accept Greger’s the sky is
    falling scenario over lecithin until he can explain why bile and dead
    cells containing lecithin and do come in to contact with these bacteria
    are not killing us with heart disease.

  • I_O

    Dr, As a 24 year old male who has been consuming at least 3 eggs a day, red meat and milk everyday, I am thinking of switching to a healthier lifestyle. What are the supplements that I should take to be healthy and gain muscle, in junction to a heavy intensity exercise and medium-lifting routine, while avoiding prostate cancer?

    • I_O

      …I was thinking of consuming the following supplements; I would like to ask your opinion on whether or not those are healthy or dangerous to take.

      1. Krill oil (Source Naturals ArcticPure Krill Oilr 500mg)
      2. Astaxanthin (Nutrex hawaii Bioastin Hawaiin Astaxanthin -12mg)
      3. Probiotic supplement (Nutrition Now PB 8 Pro-Biotic Acidophilus)
      4. A multivitamin (rainbow light men’s organic multivitamin)
      5. Whey protein powder

    • Thea

      I_O: The following is a link to Dr. Greger’s overall nutrition recommendations that apply just as much to body builders as anyone else. The page includes Dr. Greger’s suppliment recommendations. But also note what is *not* included in recommended foods: meat, diary or eggs.

      The above diet is great for avoiding prostate and other cancers, heart disease, T-2 diabetes and much more!

      Let me know if you would like some advice on how to transition from your current diet to a healthy one. I’ll just say up front that one of the moderators on this site does some serious rock climbing. He generally follows Dr. McDougall’s The Starch Solution diet with great results. That book, which includes recipes, could be a good starting place for you:

  • Tyler

    From nutritionfacts videos I am sold to the idea that ingesting excessive choline is bad for us. But I am wondering how much would be an adequate amount of choline to eat daily.

    Official recommendations are 550mg/day for men over 19yo and 425mg/day for women over 19yo, but I’ve read that the need for dietary choline may also be dependant on the intake of folate.

    Working on data taken from, I found it somewhat hard to reach 550mg/day on a eucaloric vegan diet.

    Could someone please share some thought on this subject?

    Many thanks!

    • I use and used to worry about this, too. Then I asked Jack Norris about it and he added this to the FAQ page there:
      “My diet seems to be far below the RDA for choline. Why would that be?

      As of February 2014, the USDA database still doesn’t have the choline amount listed for many of the foods. It’s likely that your choline intake is much higher than listed.”

      • Tyler

        Thanks Brandon!

        I looked at my table and, in fact, I wasn’t considering any value for oats (which I found out under another entry that has 40mg/100g) and due to a formula error I wasn’t including in the sum the choline from Soy Protein Isolate (191mg/100g).
        With everything corrected, I’m getting ~580mg/day.

        But still, I must say it wasn’t easy. I am able to eat 3500kcal/day because I work out a lot and I am trying to pack up some muscles, but if I were to eat 2500kcal/day, it would be a difficult challenge to reach the 550mg/day mark…

  • Stan Pățitul

    There is a myth about some people (Blajini) which says that 12 of them eat from only one egg

  • Stanley Niezrecki

    Question: Does Coenzyme Q-10 have any similarity to carnitine and choline? I’m wondering if CO-Q10 could lead to similar harmful TMAO generation. It is commonly suggested as a supplement when taking statins and I see it sold with red yeast rice.

  • Indigo Blue

    I developed secondary TMAU in 2009 and at the time I was eating eggs every single day and red meat. I’m not sure if I developed this due to my diet at the time but I was also under severe stress and stress and diet can developed into this horrible disease.

  • Paul Bashir

    I am genuinely curious here. I would like to know why Dr. Greger seemed to overlook this meta-analysis n = 3600 via the Mayo clinic that found such positive associations with carnitine? The rebuttal’s reference section provides many seemingly credible links:

    • LEF sells carnitine supplements (among hundreds of other supplements!) so I don’t trust their analysis of the Mayo Clinic meta-analysis.

    • Joseph Gonzales R.D.

      Hi Paul, Thanks for being patient. Dr. Greger does mention a few of the studies mentioned from that article you referenced, such as Koeth RA, Wang Z, Levison BS, et al. Intestinal microbiota metabolism of l-carnitine, a nutrient in red meat, promotes atherosclerosis. Nat Med. Apr 7, 2013

      I don’t think he is overlooking the study. It is fine to talk about the benefits of the Mayo clinic study, but it is just as important to discuss the potential harmful affects of TMAO.

  • Laurel

    Dr. Greger, it was Dr. Oz who should have been honored to have you on his show!

  • TommyBoy

    When you Google “are eggs bad for you” the top 10 sites all say yes. From places like Mayo Clinic, WebMD, Harvard Nutrition, ect. What gives?

  • Paul Bashir

    Still waiting patiently for somebody to respond to my comment…

    • Joseph Gonzales R.D.

      Thanks for your patience. I responded below. Again, it may not be so much concern with carnitine, but the potential TMAO that is produced from ingestion. It may very based on foods vs. supplements.

      In response to your question about this study I am not sure what the diet looked like for the vegetarians and I did see the study had many limitations. Nonetheless it is important to consider. Thanks for sharing it!

      Best regards,

  • iLovePhytonutrients

    Does a pregnant woman eating only plant foods risk neural tube development problems in the fetus? Is it worth eating some Wild Shrimp daily/weekly to ensure the requirements are satisfied? Are levels of 200mg/day enough to avoid complications in the womb? How about during nursing? Thanks.

  • WBord

    L-Carnitine causes plaque to build up in veins. Which supplement can treat it.

  • Do they know yet if vegans can eat eggs and not have TMAO in the blood? And, have they looked to see if quality of meat/eggs matter yet? In other words, is there TMAO in the blood after eating grassfed red meat or pastured eggs? And, not sure why only propionate bacteria in vegan gut is mentioned… there’s much microbiome to discuss.

  • Pat O’Neill

    > “It was such an honor to be on The Dr. Oz Show last week”

    That really gives me the willies. I understand the importance of educating the masses, even if you have to go on a show that promotes quackery like homeopathy. But calling it an “honor”? More like a strategic opportunity.

    I wanted to share this page on FB, but the moment a lot of my friends see that you call appearing with Oz an “honor”, they will dismiss you as they do him. And they are right to dismiss him. He flip-flops on GMOs and shills like a late-night QVC salesman.

    I encourage you to rephrase the opening line.

  • eshaw

    So, it is important to also note that dietary choline seems essential for liver function and cognitive function. I’d like more information because it could be that the right kind of choline intake in your diet is perfectly healthy and including things like soy lecithin won’t promote the growth of gut bacteria that will produce TMAO. Also, we need more information about how much choline is actually needed in our diet. It seems that maybe dietary choline is unnecessary if you have enough folate or methionine in your diet too. It is all pretty confusing, but the thing that is really weird was that the choline from less than an egg a day seemed to be correlated with increased prostate cancer risk while your average vegan diet will give you more than the amount of choline in an egg in a day. I feel like that probably means that it either isn’t the choline or maybe somehow the choline you get from vegan sources does not have the same effect.

  • alphaa10

    In December 2015, Cleveland Clinic announced discovery that naturally-occurring DMB (3,3-dimethyl-1-butanol, found in cold-pressed extra virgin olive oil and grapeseed oil) can interrupt the production of TMA (and eventually TMAO, after liver processing).

    This news may have driven many to conclude it was safe, once again, to return to a “traditional” American meat-based diet.

    However, what Cleveland did not claim is DMB prevents cardiovascular risk associated with regular intake of carnitine and choline. Instead, researchers made the more modest suggestion that DMB should reduce CV risk, and that by implication.

    In fact, the news from Cleveland remains small comfort for the population of red meat lovers who might imagine years of DMB-assured protection while indulging their favorite saturated fat-laden diet. And as it turns out, study principal Dr. Stanley Hazen, is not one of them.

    Although a self-confessed steak aficionado, Dr. Hazen is considerably more restrained about the discovery. Hazen, who had announced shortly after his initial, ground-breaking study of signal risk from carnitine and choline in red meat that what researchers needed to find, now, was a drug which would interdict the TMA-generating process, Hazen understands DMB is not revealed as a silver bullet of any kind.

    For Dr. Hazen, at least, the matter of dietary risk from red meat remains anything but academic.

    • newyorkguy

      This is very interesting, because studies from as far back as the 1950’s have suggested that olive oil could protect against heart disease. There was, for example, the 5 Country Study in the 1950’s in which it was found that of the 5 countries studied ( US, Japan, Finland, Greece and one other) Greece had the lowest rate of heart disease, but also the most risk factors. Then in the 1980’s, 1984 or 1989, I don’t remember exactly, the University of Crete looked at heart disease in rural Crete and found that heart disease was almost non-existent even though the population studied had many risk factors. I think that 40% of the men smoked and a large % of the women, obesity was prevalent and cholesterol levels were through the roof. In 2012, the University of Crete looked at 200 of the same individuals it had studied in the 1980’s and again found virtually no heart disease, even though risk factors stayed the same. This is my recollection. No cause and effect relationship was established, but Greece consumes more olive oil than any other country in the world. It’s interesting that deaths from Alzheimer’s is also very low. I use olive oil liberally and will continue to use it.

  • Your book “How Not to Die” warns against choline, which can lead to heart disease. What about choline as ch-OSA (in products like Regenemax) for hair, skin, and nails? Is this the same choline?


    Yesterday at the NYC Vegetarian Food Festival Dr. Robert Ostfeld mentioned that those who switch from a standard American diet to a wfpb diet may experience a lowering of their HDL and that he is not concerned about this because of research showing that people on a wfpb diet may have better HDL efflux capacity. So even though the good cholesterol is lower, it is more efficient at removing the bad cholesterol from the blood. I was wondering if Dr. Greger could comment on this and perhaps provide a reference.

    • Thea

      geofredo: You might want to check out the following page from Dr. McDougall: Scroll down to the last segment which talks about HDL, some studies and a reference to a longer article. This shorter article did not specifically talk about HDL, but it generally gets at the question and may lead you to the exact information you are looking for. Good luck.

    • NFModeratorKatie

      Hello! This is something I found from Dr. Esselstyn that you might be interested in: “It is not uncommon for HDL to fall when consuming plant based nutrition. Do not be alarmed. The capacity of HDL to do its job has been shown recently by scientific research that there is no relationship between the capacity of the HDL molecule to function optimally and its blood level. Recent research has confirmed that the HDL molecule can be injured and weakened when one is ingesting a pro inflammatory western diet and conversely it appears despite a lower than normal level to be optimized by anti inflammatory plant based-nutrition.” Dr Esselstyn’s FAQ

      Let me see if I can find you a reference…

  • Sky King

    What is this…. a vegetarian blog? How the hell did I end up here? I’m outta here!

  • Sam

    how do you explain high soy consumption among Asians and lower mortality rates from cancers? Wouldn’t soy contain lecithin —> —> choline as well as sunflower seeds, cauliflower?

  • Sam

    so, I may not have followed through with the logic in the video, but the Dr. mentioned that vegetarians don’t get TMEO despite intake on choline. So, choline maybe the innocent bystander ??

  • Judy Fields Davis

    Thank you so much

  • I ran across an article, the value of which I can’t really assess, which claims that ACETYL-l-carnitine is a different story:

    This is interesting to me because I (long ago) saw research indicating that a combination of acetyl-l-carnitine and alpha-lipoic acid has a strong protective effect against Alzheimer’s disease.


  • Paul Matheson

    Carnitine is bad for your heart according to a study released by a research group at the Cleveland Clinic.

  • Romi

    Was just wondering if anyone could comment on this preliminary study that was discussed on Medscape re choline supplements in pregnancy for preventing mental health conditions including schizophrenia.

    Can a Prenatal Supplement Prevent Mental Illness?
    Bret S. Stetka, MD; Robert Freedman, MD

    They recommend at least getting the RDI which seems almost impossible on a vegan diet.

    It seems most people here think supplementing in general is a bad idea, but what about for wfpb dieters in times of additional requirements like pregnancy?
    It seems the choline may also be important for other aspects of neurological development in the foetus like long term memory.
    I have read others around the web who suggest small dose choline supplements for pregnant vegans.
    Would really like some input on this, from anyone but hopefully someone from Nutrition Facts?
    Thanks in advance.

    • Thea

      Romi: Dr. Greger has recommended the book, Becoming Vegan, for when people have questions about specific nutrients. The Express Edition of the book has this to say on page 118:
      “Choline has hopped back and forth across the line between vitamin–and therefore essential–and nonvitamin. That’s because the body can produce sufficient choline unless a person’s diet is short on folate, vitamin B12, and the amino acid methoionine. … Women should bet 425 mg choline per day, and men should bet 500 mg. … There are plenty of good sources of choline. A few that are particularly rich are beans, broccoli, peas, quinoa, and soy foods.”
      In other words, even if you are relying on getting choline from your diet, there are safe and healthy foods for consuming it. One *generally* does not have to resort to eating eggs or any other animal product.
      On the other hand, your raise an interesting point about pregnancy. I don’t know the answer to that and hope that someone else will be able to jump in and offer some thoughts. I just thought that the above information would be helpful for you as a starting place.

      • Romi

        Thanks Thea, I will check out Becoming Vegan.
        Seems like pregnancy is a tricky area with most research, and very hard to prove causation with so many variables!

    • Christine Kestner

      Hi, Romi. I am Christine, a NF Volunteer Nutrition Moderator. The link you supplied is to an interview, not a research study. In my opinion, Dr. Freedman makes a lot of leaps that are not necessarily supported by evidence. The table, Dietary Reference Intakes (DRIs): Vitamins, published by the Food and Nutrition Board, Institute of Medicine, National Academies of Science, includes the following note regarding choline: “Although AIs have been set for choline, there are few data to assess whether a dietary supply of choline is needed at all stages of the life cycle, and it may be that the choline requirement can be met by endogenous synthesis at some of these stages.” AI stands for Average Intake, which is an estimate of the amount of a nutrient most healthy people consume. This comment states that people may not need to consume any choline at all, because their bodies may be able to make as much as they need. This is coming from the people who set the intake requirements for all nutrients. If you are concerned, peanuts are a good plant-based source of choline. I hope this helps!

      • Romi

        Thanks Christine,
        I probably wasnt clear about that when I posted- I did realise it was an interview, but I thought it was interesting that they were suggesting that the preliminary study results were significant enough to suggest that pregnant women start supplementing.
        It seems like the more you read, the less clear it is!
        Thanks for the info about the AIs- does make it interesting given most people who are included and presumed healthy may be consuming a SAD, which leaves us pretty grey as to what a ‘healthy’ intake of choline may look like. On the other hand, mental illness like schizophrenia can cause a lot of suffering, and if there are potential preventative measures that may do little harm (although this is also unknown), it seems worth taking note.
        I guess maybe just focusing on plant sources and getting as close as you can to recommended levels!