Hey all -
Long time lurker, first time poster, 34 years old, N with C, N first surfaced circa mid-2010. But enough about me.
I was curious if anybody more science-y than me had any thoughts or insight into two fairly notable (pre-discovery of Orexin/Hypocretin deficiency as the hallmark of N) studies performed using the amino acid supplement L-Tyrosine as a treatment for N.
The first, conducted in 1988, was run by a French doctor named Jacques Mouret. He conducted a 6-month trial with narcoleptic patients supplementing with L-Tyrosine and reported that they universally experienced a remission of symptoms after 6 months. It was published in The Lancet, and it made the New York Times:
8 patients with narcolepsy were treated with oral tyrosine. Within six months all were free from daytime sleep attacks and cataplexy (Dr. Mouret states in the Times article linked below that the findings were confirmed in 23 add'l patients):
Sounds too good to be true, right? Of course it does. The above trial was also not double-blind, placebo controlled.
A year later, some dudes and dudettes in the Dept. of Neurology at King's College Hospital in London led by one Dr. RD Elwes released what is (I am presuming) a "rebuttal study": Double-blind, placebo-controlled, 4 weeks in duration, supplementing L-Tyrosine to determine efficacy against N with C. Its findings were completely the opposite of the Mouret study:
A randomised, double-blind, placebo-controlled study of L-tyrosine was done in ten subjects with narcolepsy and cataplexy. Of twenty-eight visual analogue scales rating mood and arousal, the subjects' ratings in the tyrosine treatment (9 g daily) and placebo periods differed significantly for only three (less tired, less drowsy, more alert). Ratings of daytime drowsiness, cataplexy, sleep paralysis, night-time sleep, overall clinical response, and measurements of multiple sleep latency and tests of speed and attention did not differ significantly between tyrosine and placebo periods. Dietary supplementation with tyrosine 9 g daily for 4 weeks seems to have a mild stimulant action on the central nervous system but this effect is not clinically significant in the treatment of the narcoleptic syndrome.
My thoughts, questions and comments:
- Has anybody tried supplementing Tyrosine on a long-term basis as a treatment for N? The duration differences in the study (1 month vs. 6) are notable. There is a lack of any other information aside from these studies, at least that I can find, on the Internet.
- Tyrosine is a precursor to dopamine, epinephrine, norepinephrine. Presumably, supplementing Tyrosine would maximize dopamine levels in the brain. Dopamine agonists (e.g. amphetamine) have long been used as a treatment for N. This blog post has some interesting thoughts on the subject.
- I don't know the dosage used in the 6-month study, but the 4-week study used 9g a day (about 100 mg/kg for a 200-lb person). That's a lot! It is pretty cheap though (500g powder is ~$25 on Amazon).
- It's kind of mind-boggling to have a study like the first one and then a lack of subsequent evidence aside from the contrary study released one year later. While I doubt there is an island of cured formerly-sleepy French people chugging 10 grams of amino acids a day, it seems weird that this just kind of fell off.
- There's not really any evidence of negative sides from long-term Tyrosine supplementation, aside from it being contraindicated for use alongside MAOIs (what isn't?) and hyperthyroidism (Tyrosine has been used successfully as an alternative to synthroid and other thyroid hormone supplements because it increases the body's production of thyroid hormone).
- There is lots of anecdotal evidence on the web of Tyrosine being used successfully to promote alertness in non-N people (Google for more).
- The US military has successfully tested Tyrosine to promote alertness for soldiers in sleep-deprived and stressful situations on a short-term basis (there is another, better paper on this that I can't seem to find at the moment).
- Many people believe that prolonged Tyrosine supplementation is not beneficial because of the body's rate-limiter for conversion of the amino acid into neurotransmitter goodies , which is the tyrosine hydroxylase enzyme. However, several things have been found to increase the body's production of TH, including nicotine and sleep deprivation (and cocaine, LOL).
- There are also lots of reports on Tyrosine supplementation potentiating the effects of dopamine agonists - see this Erowid report on Tyrosine and Adderall (Google for more). Presumably this is the body "restocking" dopamine? Be careful if you take Tyrosine alongside stimulants (and possibly get more out of the stimulants you are using).
I figured if anybody would know more about this, it would be here. I have been researching alternatives, because *vigils don't work well for me at all. I am gluten-free and I find that on a daily basis the biggest contributor to my EDS is my carbohydrate intake. Ironically, I, like many others with N, find myself craving simple carbs like a maniac when I wake up from naps. Oh, what a curse we have.
Thanks for reading this far. Thoughts appreciated.