BCAAs and Keto diets

(Note: This article is a departure from our tradition of end-to-end citations, and other practices necessary for establishing high confidence in medical assertions. This departure is merely in the interest of publishing more ideas in less time, as our intensely busy lives have led to a huge backlog of unfinished articles for which the verification and explicit justification process has proved to be at least 80% of the work. Because of its importance to us, though, when we return to more fundamental ketogenic science articles, we will return that style.)

Benefits of BCAAs

If you follow the bodybuilding community, you are probably aware of some of the benefits of branched chain amino acids (BCAAs). That’s because they are known to have positive effects on muscle growth and recovery. (See for example Nutraceutical Effects of Branched-Chain Amino Acids on Skeletal Muscle, and Branched-Chain Amino Acids Activate Key Enzymes in Protein Synthesis after Physical Exercise.)

Less well known is that BCAAs have favourable effects on the brain, in particular the glial cells (brain cells that aren’t neurons, are more numerous than neurons, and turn out to be essential for supporting neurons — it seems probable that most brain afflictions are caused by problems in the glial cells). The beneficial effects of BCAAs come from their important role in the manufacture of neurotransmitters, and vital metabolic cycles such as the leucine-glutamate cycle.

Here are a couple of examples of beneficial effects of BCAA supplementation on the brain: Dietary branched chain amino acids ameliorate injury-induced cognitive impairment, Branched-chain amino acids may improve recovery from a vegetative or minimally conscious state in patients with traumatic brain injury: a pilot study, Recovery of brain dopamine metabolism by branched-chain amino acids in rats with acute hepatic failure..

The problems being helped by BCAA supplementation are similar to some of the benefits that have been shown to be helped by ketogenic diets, and this is no coincidence.

One important effect of keto-adaptation is a dramatic increase in circulating BCAAs.

This fact is one the many proposed mechanisms of the anti-epileptic properties of ketogenic diets. (See also The ketogenic diet and brain metabolism of amino acids: relationship to the anticonvulsant effect.)

There also appears to be a bit of a feedback loop, in that supplementing a ketogenic diet with BCAAs can itself increase ketogenesis relative to the same amount of other proteins.

Nonetheless, the important point to take away from this post is that a ketogenic diet itself achieves what others are striving for by ingesting expensive (and, frankly, revoltingtasting) powders. Therefore it is quite plausible that in addition to the more-studied positive nervous system effects, a ketogenic diet will improve muscle growth and recovery relative to a glycolytic diet, something already anecdotally reported.

18 replies
  1. Evinx
    Evinx says:

    Really glad to see you're back.
    Your blog is so great in that all is fact & science based. Opinions are clearly identified.
    I hope you will find time to post a bit more often.

  2. Fi
    Fi says:

    Yes – a welcome surprise to find a post from you in my Google Reader! And actually on a topic I have been interested in getting to the bottom of. I'm am glad that it supports my decision to stop taking them – they taste nasty and I'm not sure the benefits are that worthwhile for a female who isn't training excessively nor trying to pack on muscle. Thank you.

  3. fabio
    fabio says:

    Hello!I am on a cyclical ketogenic diet with weekly refeeds.I work out 3 times a week(weight training and cardio) and I use 15gr of BCAA's(the product Purple Wraath)pre/intra workout.Does that interefere with my fat-loss?

  4. L. Amber Wilcox-O'Hearn
    L. Amber Wilcox-O'Hearn says:

    Hi! I don't know of any reason it would interfere with fat loss. Is there some particular mechanism you are concerned about? As far as I can tell, BCAAs would only enhance ketosis and muscle growth. My point is simply that ketosis itself already increases circulating BCAAs without ingesting extra.

  5. Anonymous
    Anonymous says:

    Could someone help me finding articles wheres explained how the muscle grows on glycolytic diet and keto diet. And how those processes differs.

  6. Jeremy Tyler
    Jeremy Tyler says:


    I really enjoyed this. I have a question I have been looking all over for though. When I wake up in the morning and I am fasted I don't usually have anything but coffee. I then go for a morning workout still fasted. My question is, when exercising fasted (be it cardio or strength) should I take BCAA's before or does being keto-adapted take care of that? Should I take a protein shake after workout (strength workout that is). Unfortunately Volek and Phinney did not do studies or after workout supplements (whey protein in this case). Thanks.

  7. L. Amber Wilcox-O'Hearn
    L. Amber Wilcox-O'Hearn says:

    Hi Jeremy. Thank you for the comments, and I'm sorry for the long delay. If the question is whether you will have better strength gains with added BCAAs after already being keto-adapted, I really have no idea. I don't think that experiment has been done. It probably wouldn't hurt, but I don't know if it's worth the expense. There are many schools of thought about post-workout nutrition, and I don't know the ultimate answer for that either. Sorry I can't help more!

  8. Neeraj Engineer
    Neeraj Engineer says:

    Thanks for your blog. Awesome stuff.
    Can you speak to blood glucose reducing properties of BCAAs line Leucine, Lysine and Isoleucine? I believe these are Ketogenic amino acids (http://en.wikipedia.org/wiki/Ketogenic_amino_acid).
    I found this bodybuilding hack where they use Leucine (instead of exogenous insulin) to reduce Blood Glucose to enter ketosis more readily. (http://www.t-nation.com/free_online_article/sports_body_training_performance/isolated_pecs_big_shoulders_and_instant_ketosis)
    Thanks in advance.

  9. L. Amber Wilcox-O'Hearn
    L. Amber Wilcox-O'Hearn says:

    Hi, Neeraj. Thanks for your question.

    The branched chain amino acids (BCAAs) are leucine, isoleucine and valine. These are the ones that have been used in most of the studies showing the kind of benefit we were alluding to. However, some studies have shown that most or all of the benefit is likely to come from the leucine alone.

    The ketogenic amino acids are leucine and lysine. They are only ketogenic, meaning that if they get metabolised they can't be used for gluconeogenesis. Isoleucine, phenylalanine, tryptophan and tyrosine can be glucogenic or ketogenic.

    So, one hypothesis you might have is that it is the ketogenic nature of leucine that confers its benefits, and that lysine would also have these benefits. I haven't seen any studies showing benefits of lysine. I think it hasn't really been tested.

    One of the links in the article shows that supplementing with BCAAs enhances ketosis (and again I suspect that it is due to the leucine), so that is consistent with what you read.

  10. Esmée La Fleur
    Esmée La Fleur says:

    I have heard Donald Layman and Michael Eades discuss leucine in interviews with Jimmy Moore. Layman believes that a threshold of 30 grams of protein must be reached at every meal in order for the proein to be effectively utilized by our bodies and the reason he gave is that that is how much it takes to get enough leucine and the leucine is the rate-limiting amino acid…or something like that. Eades says that in order for a person to loose weight on a Ketogenic diet they need to get 10-12 grams of leucine per day which requires a rather large total protein consumption. I believe he supplements many of his obese patients with extra leucine. Obviously, these two men are on the other end of the spectrum from Rosedale and Gedgaudas. Any thoughts?

  11. Esmée La Fleur
    Esmée La Fleur says:

    I should cliff that Layman's studies have been done with lower carb diets that were NOT Ketogenic, so I am not sure the results applicable to people on a Ketogenic diet. I will also add that both Rosedale and Gedgaudas, as proponents and practitioners of lower protein intakes, appear to be remarkable healthy.

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