DAO more...
L-theanine and allergy
Science Score:
★ ★ ★ ★ ★
Thanks, John. L-theanine’s “mechanism of action” is quite interesting.
L-theanine has shown some promise as a modulator of allergic reactions. (
R) A major event in allergic reactions is the secretion of histamine from immune cells known as mast cells. Mast cells can be thought of as the first responders of the immune system, they are constantly sensing the environment and when they detect something potentially harmful they secrete a wide range of factors to kick start the immune response. When mast cells detect something as harmful (even if it’s harmless) this causes an allergic reaction. (
R) Theanine inhibits histamine release from mast cells.
Interestingly, this inhibition of histamine also ties in with L-theanine’s glutamate inhibitory activities as well. Histamine can induce glutamate release (
R), which as we’ve established above, is an excitatory neurotransmitter our bodies need. Excess histamine may cause an unhealthy build-up of glutamate, although there is some evidence that there is an upper maximum of glutamate build-up associated with histamine (
R).
L-theanine mechanism of action
Science Score:
★ ★ ★ ★ ★
So the interesting questions then becomes how does L-theanine link all these together, and is there a single gene or SNP which is of particular interest?
Lets look at histamine first, a major gene involved in histamine metabolism is
AOC1, which encodes for the enzyme Di-amine Oxidase (DAO – pay attention to that abbreviation as it’s the cause of much confusion). In health DAO functions to break down histamine following its release from mast cells, curtailing the immune response. There are several SNPs within
AOC1 which are associated with reduced DAO activity, resulting in histamine intolerance, which is characterized by symptoms often associated with allergy such as headaches, flushing of the skin and irritation (
R).
The benefit of L-theanine here is clear. By suppressing histamine release from mast cells (
R), it is prevented from building up to harmful levels, even in those with reduced DAO activity.
We’ve already described how L-theanine can inhibit stress by blocking glutamate receptors (
R). As excess histamine can lead to the buildup of glutamate there’s a clear mechanism for impaired DAO activity leading to increased histamine, leading to increased glutamate. L-theanine works by both preventing histamine release, and also blocking glutamate activity as well.
AOC1/DAO and DAO/DAAO
There’s a nice indirect mechanism linking DAO, histamine and glutamate.
However, if you read around on the internet, you may find articles discussing a direct action for DAO interacting with glutamate. While there may be evidence linking them directly I’ve not come across it; rather I think it’s a case of confusing DAO the enzyme with
DAO the gene. DAO is encoded for by the
AOC1 gene and functions to breakdown histamine (
R). There is however a
DAO gene which confusingly encodes for an enzyme called d-amino acid oxidase (DAAO), which is involved in glutamate metabolism (
R).
See also:
You say DAO, I say DAAO
Quite why it seemed a good idea for DAO to be encoded for by
AOC1 and DAAO to be encoded for by
DAO I’ll never know, but I think this is the basis for much confusion. So be careful when you’re trying to interpret your genetic results!
L-theanine dosage and complementary supplements
Ok, taking the mic back from Aaron for some closing thoughts.
I have found L-theanine to be an effective nootropic that produces a calm focus. For me, it’s an effective tool for writing, meditating, creative bursts, and even to unwind and get to sleep at the end of the day. I also like it socially.
If you’re using theanine as an anti-anxiety supplement, the calming effects for me were greatest when paired with GABA and valerian. Keep in mind that both GABA and valerian can upset the stomach, so start slow. I also don’t recommend this stack for daily use over extended periods of time, best to cycle on and off.
As we discussed, theanine lowers blood pressure. Because there can be side effects, I would encourage everyone to experiment with different doses to see what amount of theanine suits them best. Some will tolerate 200mg quite well, while others may want to dose more in line with the studies that used 50mg.
Choosing a theanine supplement
If you’ve read thus far and want to add theanine to your supplement stack, I’ve included a short section below that gives a tour around some of the best theanine products on the market, standalone supplements, as well as a couple blends that have positive reviews and are made with good manufacturing practices from brands I trust.
https://www.mygenefood.com/experience-l-theanine-dose-benefits-side-effect
not sure about this but found it decide for yourself
