Doctor's Note

This is the third of a four-part video series (mentioned in Uprooting the Leading Causes of Death) on natural ways to boost serotonin in the brain. Human Neurotransmitters in Plants shows that plants themselves can contain serotonin. The Wrong Way to Boost Serotonin is a cautionary tale about tryptophan supplements, and we’ll next discover the Best Way to Boost Serotonin. The arachidonic acid in animal foods may also contribute to negative mood states through an inflammatory mechanism. See, for example, my videos Plant-Based Diet & MoodInflammatory Remarks About Arachidonic Acid; and Chicken, Eggs, and Inflammation

For further context, check out my associated blog posts: How To Boost Serotonin NaturallyTop 10 Most Popular Videos of the YearSaffron vs. Prozac for Depression; and Treating Parkinson’s Disease with Diet.

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  • Michael Greger M.D.

    This is the third of a four-part series (mentioned in Uprooting the Leading Causes of Death) on natural ways to boost serotonin in the brain. Wednesday’s video-of-the-day Human Neurotransmitters in Plants noted that plants themselves can contain serotonin. Yesterday’s The Wrong Way to Boost Serotonin was a cautionary tale about tryptophan supplements, and Monday we’ll close with the Best Way to Boost Serotonin. The arachidonic acid in animal foods may also contribute to negative mood states through an inflammatory mechanism. See, for example, my videos Plant-Based Diet & Mood, Inflammatory Remarks About Arachidonic Acid, and Chicken, Eggs and Inflammation. Arachidonic acid is one of more than a thousand different topics I cover. If you haven’t yet, you can subscribe to my videos for free by clicking here.

    • HemoDynamic, M.D.

      I’m ‘Trypin’ out right now because now I understand why certain people in my life have gone from
      this  =>  :-{
      to this => ;-}
      after going Vegan.
      Trypin’ Vegans are Happy Vegans!
      ;-}}}}}}}}  (No those aren’t trails those are smiles)

      • carfree

        and certainly not double chins!

    • SJ M.D.

      I knew it! Always get in a bad mood, when someone tries to serve me turkey……. ;-)

  • Slim_Langer

    Too much teasing. I’ll warn you more about this tomorrow.

  • HemoDynamic, M.D.

    Kinda like the Grateful Dead, they Tryptophan.

    Get it, they ” ‘Tripped’ to fame”

  • Thea

    argh!  Another cliffhanger.  I eagerly await.

    • SJ M.D.

      Didn`t Michael say tomorrow? Hence saturday – great:  In the future 6 informative videos pr week !!! :-)

      • Thea

         hee, hee.  Good catch!  I hadn’t caught that. 

        I’ve been impressed with 5 days/week, but you would never hear me complain if the schedule got ramped up.

      • Michele Comeau

        OK Dr. Greger . . . we are counting on your to not let us down!  Will be watching for the next video tomorrow :-}

  • Gabriel

    So how do you increase serotonin in the brain?
    If you do not eat protein I don´t know from where you will take tryptophan.

  • Dermot Dunphy

    I cannot get butternut squash seeds in Ireland, will pumpkin
    seeds do. Dermot

  • jakov

    Isn’t this a positive spin on the different balance of amino acids in plant foods? Great if that’s the balance needed, but what if this causes an imbalance? I’ve tried a phenylalanine supplement with some success, but the ratios of other amino acids in plant foods are still imbalanced for me. I’ve been strictly vegan for over a decade and it has become apparent
    that this is a problem for me which I recently resorted to dairy to
    solve. I’d love to be vegan again, but can no longer live on foods with this amino acid imbalance. Please help!

    • Toxins

      It is extremely difficult to become protein deficient eating any diet unless you are malnourished or are a fruitarian.

      “Plant protein can meet protein requirements when a variety of plant foods is consumed and energy needs are met. Research indicates that an assortment of plant foods eaten over the course of a day can provide all essential amino acids and ensure adequate nitrogen retention and use in healthy adults; thus, complementary proteins do not need to be consumed at the same meal ”

      As Jeff Novick puts it..
      Many say that plants foods are incomplete

      If “incomplete” means not containing all the essential amino acids then…. (the incomplete protein theory)

      1) All plant foods are complete as they contain all the essential amino acids.

      2) the only food that is not a complete protein is an animal food, gelatin.

      If “incomplete” means lacking in sufficient quantity of one or more amino acids…(the limiting amino acid theory)

      1) Getting all the amino acids in at once at the same meal, or even in the same day, as some may suggest, is not necessary due to the amino acid pool, which is a circulating level of amino acids in the blood, that the body can draw from if needed. As long as one follows a whole foods plant based diet, the amino acid pool will maintain a sufficient stock of any potentially needed (or limiting) amino acids.

      2) However, as long as one consumes enough calories, eats a variety of food, and limits junk foods and refined foods, and is not an all fruit diet, then they will get in enough protein and enough amino acids in sufficient quantity. There will be no limiting amino acids

      3) there is some evidence that the amino acids that are slightly lower (but adequate) in plant foods, may actually be a benefit to health and longevity and not a concern. This evidence stems from the fact that eating foods that resemble the protein structure of humans causes the liver to release excess amounts of the growth hormone, IGF-1, which accelerates aging and promotes tumor growth.

      • jakov

        The problem is not lack of sufficient quantity of amino acids in plant foods, but of the relative quantities. According to the video on this page for example, tryptophan is relatively higher in plant foods in proportion to other amino acids which compete to cross the blood brain barrier, which results in higher serotonin levels in vegans. This may be good for avoiding depression, but what if it’s not serotonin but other neurotransmitters or hormones that a person needs more of?

        As I mentioned, I was strictly vegan for over a decade, until a few days ago. I had an imbalance of some sort. Eliminating soy helped. I tried a supplement containing milk protein and it seemed to help. I then reluctantly resorted to dairy and molluscs, which also seem to have helped. I hate to depend on these, but can’t function as I was.

        • Toxins

          Perhaps your past vegan diet was not healthful, because there is nothing your body needs (except b12) that you can’t find in plants. A diet based on whole plant foods will be the most nutritious.

          • jakov

            Again, this does not address my question. I did not claim that there’s anything absent or insufficient in quantity in a vegan diet. Please try to understand my previous posts.

          • jakov

            Otherwise, if possible, please refer my question to somebody who is able to answer. Thanks for trying anyway.

          • j

            To put it another way: This video explains how extra serotonin is produced rather than other neurotransmitters because of the ratio of tryptophan to other amino acids in plant foods. What if it’s not more serotonin that’s needed, but rather, more of the other neurotransmitters that tryptophan crowds out in crossing the blood-brain barrier?

            …Btw, Am I wasting my time checking this page for an answer? Toxins, it’s not about deficiency, it’s about imbalance specifically for neurotransmitters & hormones. Repeating that all nutrients are in vegan diet in plentiful quantities (I already knew that, but it’s not the point) shows lack of understanding of the question and of the video on this page. I sincerely hope there’a a vegan solution.

        • I don’t think you will find an answer to your question. There are certainly plant foods that can cause problems (e.g. allergies, food intolerance, autoimmune triggers). Sounds like you are working things out for yourself. You found that soy is a problem for you. One approach I sometimes recommend to patients is to try Dr. McDougall’s Diet for the Desperate which he outlines in his newsletter article in December 2002. The mental health issues are complex and many are not diet related or amenable to dietary intervention… the book by Robert Whitaker, Anatomy of an Epidemic, has some interesting information on the natural time course and treatment of conditions such as depression, anxiety and schizophrenia. Working with a supportive and knowledgeable health care professional is always advisable if you are having symptoms.

          • jakov

            Thanks for the reply. Even though there’s no easy answer I appreciate the resolution here, and your recommended references appear useful. My own symptoms have cleared up with the dietary changes I’ve mentioned. I’ll try using Dr McDougall’s method for identifying specific foods, and I’ll look for the R. Whitaker reading.

        • Thea

          jakov: I have another idea for you to consider. Dr. Greger has a video about a boy who got sick after he became vegetarian. It turns out that the boy had a genetic defect where his body was not able to create one of the NONessential amino acids. He could either start eating meat/dairy/eggs or he could take a pill to supply his body with the one amino acid his own body could not make – but which most other people’s bodies can make.

          Of course, the pill was the safest approach and that’s what the boy did. And the problem was solve.

          The condition is rare, but obviously it does exist. I am a lay person and have no idea if this applies to you or not. But if you had the inclination, maybe there would be a way for you to find out if you have a similar problem.

          Just a thought. Good luck.

          • jakov

            Thanks. I do seem to be in a similar situation. Maybe I could be tested for something similar. I’d rather not post specific details online, but I apparently have a natural imbalance. I have tried a single amino acid supplement, i.e. phenylalanine, as I mentioned, which did help, but I don’t think it’s safe long-term (tryptophan supplements for example are dangerous, and it doesn’t completely solve the problem. I think there are probably various amino acids involved, and it’s complicated – I can only guess the theory and see what works in practice. I think I need a natural wholefood protein source with the right balance of various amino acids. I feel restored with the animal proteins, although ethically conflicted.

  • Kate Carpenter


  • Hendrik

    Vitamin D is also important to convert tryptophan to serotonin in the brain:-