Theanine: Difference between revisions

This compound is used as a [[psychoactive class::nootropic]] for its calming and relaxing properties. It is often taken in combination with [[caffeine]] as it has been shown to mitigate its negative aspects, such as [[anxiety]], [[increased blood pressure]] and [[wakefulness|diminished sleep quality]], while possibly improving upon the positive aspects.<ref>{{cite journal | vauthors=((Lyon, M. R.)), ((Kapoor, M. P.)), ((Juneja, L. R.)) | journal=Alternative Medicine Review: A Journal of Clinical Therapeutic | title=The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial | volume=16 | issue=4 | pages=348–354 | date= December 2011 | issn=1089-5159}}</ref><ref>{{cite journal | vauthors=((Lu, K.)), ((Gray, M. A.)), ((Oliver, C.)), ((Liley, D. T.)), ((Harrison, B. J.)), ((Bartholomeusz, C. F.)), ((Phan, K. L.)), ((Nathan, P. J.)) | journal=Human Psychopharmacology | title=The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans | volume=19 | issue=7 | pages=457–465 | date= October 2004 | issn=0885-6222 | doi=10.1002/hup.611}}</ref><ref>{{cite journal | vauthors=((Kimura, K.)), ((Ozeki, M.)), ((Juneja, L. R.)), ((Ohira, H.)) | journal=Biological Psychology | title=L-Theanine reduces psychological and physiological stress responses | volume=74 | issue=1 | pages=39–45 | date= January 2007 | issn=0301-0511 | doi=10.1016/j.biopsycho.2006.06.006}}</ref><ref name="Kahathuduwa2017">{{cite journal | vauthors=((Kahathuduwa, C. N.)), ((Dassanayake, T. L.)), ((Amarakoon, A. M. T.)), ((Weerasinghe, V. S.)) | journal=Nutritional Neuroscience | title=Acute effects of theanine, caffeine and theanine-caffeine combination on attention | volume=20 | issue=6 | pages=369–377 | date= July 2017 | issn=1476-8305 | doi=10.1080/1028415X.2016.1144845}}</ref> Its ability to enhance attention has been repeatedly verified.<ref name="Kahathuduwa2017" /><ref name="Owen2008">{{cite journal | vauthors=((Owen, G. N.)), ((Parnell, H.)), ((De Bruin, E. A.)), ((Rycroft, J. A.)) | journal=Nutritional Neuroscience | title=The combined effects of L-theanine and caffeine on cognitive performance and mood | volume=11 | issue=4 | pages=193–198 | date= August 2008 | issn=1476-8305 | doi=10.1179/147683008X301513}}</ref><ref name="Haskell2008">{{cite journal | vauthors=((Haskell, C. F.)), ((Kennedy, D. O.)), ((Milne, A. L.)), ((Wesnes, K. A.)), ((Scholey, A. B.)) | journal=Biological Psychology | title=The effects of L-theanine, caffeine and their combination on cognition and mood | volume=77 | issue=2 | pages=113–122 | date= February 2008 | issn=0301-0511 | doi=10.1016/j.biopsycho.2007.09.008}}</ref><ref>{{cite journal | vauthors=((Einöther, S. J. L.)), ((Martens, V. E. G.)), ((Rycroft, J. A.)), ((De Bruin, E. A.)) | journal=Appetite | title=L-theanine and caffeine improve task switching but not intersensory attention or subjective alertness | volume=54 | issue=2 | pages=406–409 | date= April 2010 | issn=1095-8304 | doi=10.1016/j.appet.2010.01.003}}</ref><ref>{{cite journal | vauthors=((Kelly, S. P.)), ((Gomez-Ramirez, M.)), ((Montesi, J. L.)), ((Foxe, J. J.)) | journal=The Journal of Nutrition | title=L-theanine and caffeine in combination affect human cognition as evidenced by oscillatory alpha-band activity and attention task performance | volume=138 | issue=8 | pages=1572S-1577S | date= August 2008 | issn=1541-6100 | doi=10.1093/jn/138.8.1572S}}</ref><ref>{{cite journal | vauthors=((Giesbrecht, T.)), ((Rycroft, J. A.)), ((Rowson, M. J.)), ((De Bruin, E. A.)) | journal=Nutritional Neuroscience | title=The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness | volume=13 | issue=6 | pages=283–290 | date= December 2010 | issn=1476-8305 | doi=10.1179/147683010X12611460764840}}</ref><ref>{{cite journal | vauthors=((Foxe, J. J.)), ((Morie, K. P.)), ((Laud, P. J.)), ((Rowson, M. J.)), ((Bruin, E. A. de)), ((Kelly, S. P.)) | journal=Neuropharmacology | title=Assessing the effects of caffeine and theanine on the maintenance of vigilance during a sustained attention task | volume=62 | issue=7 | pages=2320–2327 | date= June 2012 | issn=1873-7064 | doi=10.1016/j.neuropharm.2012.01.020}}</ref>

A recent systematic review of the [https://gratefulearthcoffee.com/blogs/coffee-and-productivity/benefits-of-l-theanine effects of theanine and caffeine] has confirmed that the combination seems to improve aspects of attention.<ref>{{cite journal | vauthors=((Camfield, D. A.)), ((Stough, C.)), ((Farrimond, J.)), ((Scholey, A. B.)) | journal=Nutrition Reviews | title=Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis | volume=72 | issue=8 | pages=507–522 | date= August 2014 | issn=1753-4887 | doi=10.1111/nure.12120}}</ref> The combination of L-theanine and caffeine may improve attention more than caffeine alone.<ref name="Owen2008" /><ref name="Haskell2008" />

Theanine is structurally similar to the excitatory [[neurotransmitter]] [[glutamate]], and in accordance, binds to glutamate [[receptor]]s, though with much lower affinity in comparison. Specifically, it binds to ionotropic glutamate receptors including the [[AMPA]] and [[kainate]] receptors and, to a lesser extent, the [[NMDA]] receptor.<ref name="Nathan2006">{{cite journal | vauthors=((Nathan, P. J.)), ((Lu, K.)), ((Gray, M.)), ((Oliver, C.)) | journal=Journal of Herbal Pharmacotherapy | title=The neuropharmacology of L-theanine(N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent | volume=6 | issue=2 | pages=21–30 | date= 2006 | issn=1522-8940}}</ref><ref>{{cite journal | vauthors=((Kakuda, T.)), ((Nozawa, A.)), ((Sugimoto, A.)), ((Niino, H.)) | journal=Bioscience, Biotechnology, and Biochemistry | title=Inhibition by theanine of binding of [3H]AMPA, [3H]kainate, and [3H]MDL 105,519 to glutamate receptors | volume=66 | issue=12 | pages=2683–2686 | date= December 2002 | issn=0916-8451 | doi=10.1271/bbb.66.2683}}</ref><ref>{{cite journal | vauthors=((Kakuda, T.)) | journal=Pharmacological Research | title=Neuroprotective effects of theanine and its preventive effects on cognitive dysfunction | volume=64 | issue=2 | pages=162–168 | date= August 2011 | issn=1096-1186 | doi=10.1016/j.phrs.2011.03.010}}</ref><ref name="Kakuda2002">{{cite journal | vauthors=((Kakuda, T.)) | journal=Biological & Pharmaceutical Bulletin | title=Neuroprotective effects of the green tea components theanine and catechins | volume=25 | issue=12 | pages=1513–1518 | date= December 2002 | issn=0918-6158 | doi=10.1248/bpb.25.1513}}</ref> It acts as an [[antagonist]] of the former two sites<ref name="Kakuda2002" /> and as an [[agonist]] of the latter site.<ref name="Wakabayashi2012">{{cite journal | vauthors=((Wakabayashi, C.)), ((Numakawa, T.)), ((Ninomiya, M.)), ((Chiba, S.)), ((Kunugi, H.)) | journal=Psychopharmacology | title=Behavioral and molecular evidence for psychotropic effects in L-theanine | volume=219 | issue=4 | pages=1099–1109 | date= February 2012 | issn=1432-2072 | doi=10.1007/s00213-011-2440-z}}</ref> In addition, it inhibits glutamine transporters and glutamate transporters, and thus acts as [[reuptake inhibitor]] of glutamine and glutamate.<ref name="Kakuda2002" /><ref>{{cite journal | vauthors=((Sugiyama, T.)), ((Sadzuka, Y.)), ((Tanaka, K.)), ((Sonobe, T.)) | journal=Toxicology Letters | title=Inhibition of glutamate transporter by theanine enhances the therapeutic efficacy of doxorubicin | volume=121 | issue=2 | pages=89–96 | date=30 April 2001 | issn=0378-4274 | doi=10.1016/s0378-4274(01)00317-4}}</ref><ref>{{cite journal | vauthors=((Sugiyama, T.)), ((Sadzuka, Y.)) | journal=Biochimica Et Biophysica Acta | title=Theanine and glutamate transporter inhibitors enhance the antitumor efficacy of chemotherapeutic agents | volume=1653 | issue=2 | pages=47–59 | date=5 December 2003 | issn=0006-3002 | doi=10.1016/s0304-419x(03)00031-3}}</ref>

Theanine increases [[dopamine]], [[GABA]], and [[glycine]] levels in various areas of the brain.<ref name="Nathan2006" /><ref name="Wakabayashi2012" /><ref>{{cite journal | vauthors=((Yamada, T.)), ((Terashima, T.)), ((Wada, K.)), ((Ueda, S.)), ((Ito, M.)), ((Okubo, T.)), ((Juneja, L. R.)), ((Yokogoshi, H.)) | journal=Life Sciences | title=Theanine, r-glutamylethylamide, increases neurotransmission concentrations and neurotrophin mRNA levels in the brain during lactation | volume=81 | issue=16 | pages=1247–1255 | date=29 September 2007 | issn=0024-3205 | doi=10.1016/j.lfs.2007.08.023}}</ref><ref name="Yokogoshi1998">{{cite journal | vauthors=((Yokogoshi, H.)), ((Kobayashi, M.)), ((Mochizuki, M.)), ((Terashima, T.)) | journal=Neurochemical Research | title=Effect of theanine, r-glutamylethylamide, on brain monoamines and striatal dopamine release in conscious rats | volume=23 | issue=5 | pages=667–673 | date= May 1998 | issn=0364-3190 | doi=10.1023/a:1022490806093}}</ref> It also affects [[serotonin]] in a manner which is still a matter of debate in the scientific community, with separate studies showing increases and decreases in brain serotonin levels using similar experimental protocols.<ref name="Yokogoshi1998" /><ref>{{cite journal | vauthors=((Yokogoshi, H.)), ((Mochizuki, M.)), ((Saitoh, K.)) | journal=Bioscience, Biotechnology, and Biochemistry | title=Theanine-induced reduction of brain serotonin concentration in rats | volume=62 | issue=4 | pages=816–817 | date= April 1998 | issn=0916-8451 | doi=10.1271/bbb.62.816}}</ref>

 

*[https://www.erowid.org/experiences/subs/exp_Theanine.shtml Erowid Experience Vaults: Theanine]

[[Category:Psychoactive substance]]

[[Category:Nootropic]]