Posted by Ron Hill on December 14, 2003, at 22:42:06
In reply to Re: Motivation problems,Rhodiola Rosea,L-Theanine » Ron Hill, posted by btnd on December 14, 2003, at 5:20:33
Hi bntd,
> I have questions for you. I've tried digging the studies/abstracs and couldn't find any connection between L-Theanine and GABA. Every website mentions that it increases/releases GABA, but I've seen no studies showing that. Could you point them to me?
Have you seen the following document? Use the hotlinks associated with the references:
http://www.lifelinknet.com/siteResources/ArchivePages/Theanine-Sharpe.asp#fn22
Here is a quote from the above document regarding l-theanine and GABA release:
<start quote>
The relaxing effects of theanine partly depend on its ability to interact with the brain’s glutamatergic system. For example, theanine has been reported to induce the release of gamma-amino butyric acid (GABA), the main inhibitory neurotransmitter known for counterbalancing the stimulatory effects of glutamate (reference 22). Just as glutamate excites nerve cells into greater activity, GABA (which is produced in the brain from glutamate) quiets them down. Unfortunately, it’s difficult to supplement with GABA because it doesn’t cross the blood-brain barrier readily. Theanine, on the other hand, crosses the blood-brain barrier with relative ease. This makes theanine rather than GABA itself the supplement of choice for relieving anxiety and stress.
<end quote>I have provided a link to reference number 22 below. Unfortunately, the abstract is unavailable and, therefore, one would need to purchase a copy of the paper in order to examine and critic the arguments set forth in the document.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=4397636&dopt=Abstract
Anecdotally speaking, I feel the calming effect of increased GABA beginning roughly 15 – 20 minutes after I take a 200 mg capsule of l-theanine. The feeling reminds me of Neurontin.
> Also why such high dose of L-Theanine and what you are using it for? Just curious.. ;-)
Everything I’ve read leads me to believe that this stuff is very safe. Therefore, I have no concerns about taking 400 mg/day. In fact, every now and then I take 600 mg/day. As to the specific scenario that lead to my current dosing schedule, the capsules I bought are 200 mg each and the effectiveness of a one-capsule dose begins to wane after about five hours. Therefore, I take two (or sometimes three) doses in order to provide coverage for the entire day.
For the past month and a half or so, I’ve been taking l-theanine to treat my bipolar II related dysphoric mood states (i.e.; irritability, GRRRRRRRR!). So far it’s working great. Time will tell regarding its long-term efficacy. In addition to the nice GABA release, it also gives me some added motivation and energy (i.e.; improved dopamine release), and it supposedly lowers cortisol (which I believe to be true).
Have you seen my original post regarding l-theanine? If not, here is the link:
http://www.dr-bob.org/babble/alter/20031104/msgs/281539.html
-- Ron
poster:Ron Hill
thread:288550
URL: http://www.dr-bob.org/babble/alter/20031204/msgs/289860.html