How much theanine is in tea?

 

I just looked this up related to someone bringing it up in a biohacking group, of course related to taking it as a pill supplement instead of drinking tea.  Those people love supplements, the more experimental the better, it sometimes seems.  Theanine should be harmless enough, in a normal dosage range.  But what is that?

WebMD says this; they would never steer you wrong:

L-theanine is naturally found in tea and some mushrooms. As medicine, L-theanine has most often been used by adults in doses of 200-400 mg by mouth daily for 4-8 weeks. Speak with a healthcare provider to find out what dose might be best for a specific condition.

People in that group said that 100 mg is probably ok for a starter dose, but if they mean to take that twice a day it's back to 200.  It would depend on why someone is taking it.  WebMD says this:

Possibly Effective for:  Memory and thinking skills (cognitive function). Taking L-theanine by mouth might help healthy people stay focused. It isn't clear if adding L-theanine to caffeine works better than using either of those ingredients alone.

There is interest in using L-theanine for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.

Healthline said this, more in line with what those people in that group were using it for:  

It’s said to help ease anxiety, stress, and reduce insomnia.  Before trying it out yourself, learn more about the potential health benefits, as well as any possible risks or complications.

So those two not so reliable, light content health sites said completely opposite things; that can happen.  People in that group thought that it could provide different benefits, and were taking it for different reasons.

So how much is in tea, especially in relation to standard supplementation amounts?  Scanning a few sources turned up different measured amounts, but this seems kind of middle of the road for other results:

Theanine and Caffeine Content of Infusions Prepared from Commercial Tea Samples

Materials and Methods:

Theanine and caffeine contents of 37 commercial white, green, oolong, black, and pu-erh tea samples were quantified by high-performance liquid chromatography-diode array detector.

Results:

The mean L-theanine content of white, green, oolong, and black teas were 6.26, 6.56, 6.09, and 5.13 mg/g, respectively. The same values for caffeine content were 16.79, 16.28, 19.31, and 17.73 mg/g.

So just over 6 mg per gram of dry tea.  The caffeine values seem normal enough; measured amounts typically ranges between 15 and 25 mg/g, so maybe a little on the low side, but these are "commercial" products, probably low to medium low in quality level.  Both theanine and caffeine range might bump a little in relation to testing or consuming slightly better tea, but probably not too much.

Extraction rate could be a little clearer, but it seems to follow the same pattern as for caffeine, so for a relatively complete brewing process something like 90% may be extracted, possibly a little less:

So from there it's really down to daily intake, amount of dry leaf prepared per day, which is going to vary for everyone.  Someone could brew two rounds of tea a day and consume 10 grams, but I tend to brew 9 or 10 grams for each Gongfu brewing session.  10 grams at 6 mg / gram of extraction (which may be slightly lower) is 60 mg; not a lot, in relation to taking supplements, which again might be in a range of 200 mg per day (taken as pills), but that would just depend.

It's interesting that they seemed to test one pu'er sample and found no theanine in it.  That could be an anomaly, or it could be that they tested shou pu'er and fermentation really does transition that compound to become something else.  Here is that summary:

Those results are all over the place.  There may well be a correlation between theanine levels and buds and fine leaves content, versus older leaves, as there is for caffeine level, but you can't really spot an underlying cause input from this kind of list.  It would seem natural for there to be a divide between variety Sinensis and variety Assamica plants, but this definitely wasn't set up to isolate that input, or any other, really.  One sample of any given type doesn't even tell you with any certainty that other samples of the same type would follow the same pattern, and have a similar amount in them.

For me it's enough to have as a guess that we might be ingesting around 6 mg per gram of tea, since I'm not even sure what theanine would do anyway.  There's a vague understanding that it calms you while caffeine gives you a lift, so I guess a very mild speedball effect, but not much of one.  The effect would be limited if your daily consumption probably lands between 60 and 120 mg per day, and only that higher level based on drinking 20 grams worth of tea a day, which is a lot.

I glanced at a couple of other studies and they're in this general range, with some showing some black tea amounts that are a good bit higher (in this study example):

High levels of milk resulted in a marked lowering of the level of detectable l-theanine. Contrary to previous research, a standard (200 ml) cup of black tea was found to contain the most l-theanine (24.2 ± 5.7 mg) while a cup of green tea contained the least (7.9 ± 3.8 mg).

So their findings were way off that other scale, which is more typical of what other sources that I looked through were saying.  It can be confusing comparing amount per brewed cup with a derived amount per gram of dry leaf, which to me is easier to work with.  They seemed to be making tea from a standard 2 or 2 1/2 gram commercial tea bag, and then infusion time surely would've been a limitation to extraction, since you don't brew tea bags for 10 minutes.  The point here is more that studies vary on general findings, as that one study varied quite a bit in relation to measured amounts and individual tea versions, even within type categories (black, green, and so on).

Someone could keep digging if they really wanted to know, but it would be hard to factor in what these studies are not testing for:  theanine amounts in relation to tea plant material type (buds, fine leaves, old leaves), and related to tea quality level.  Guessing that a final average experienced result is around 6 grams per gram of dry tea seems good enough, with extracted amount probably just below that.  

We're taking in a significant amount of theanine when drinking tea, just not getting dosed on the high side compared to the range of 100 mg to 400 mg of intake per day.  20 grams of tea--a good bit to drink in one day, which probably would exceed that 100 mg theanine input level--might work out to 20 mg of caffeine per dry gram of ingested tea, or 400 mg of caffeine per day, the general recommended daily limit.  

That is on the high side of most caffeine level test findings; 15 to 20 grams per mg is probably a more standard range, with extraction potentially between 85 and 90%.  My point in venturing into this second tangent is that it seems that you can drink 20 grams worth of tea per day, related to not exceeding a standard caffeine input level.  Then a daily dose of over 100 mg of theanine might offset some negative effects of caffeine, feeling "jittery," as people understand might happen.  It's not completely clear that would occur, but then theanine and caffeine aren't necessarily the only two active compounds in tea, the only two that would have any effect on how you feel.

What does "tea drunk" mean?

 

A question in Reddit inspired me to write out a detailed answer about this, what people mean by "tea drunk?"  The actual question, now deleted, related to asking if cold tea can make you tea drunk, but prior to that it's necessary to consider what it even means.  My answer was this:

"Tea drunk" is really used in two completely different ways by tea enthusiasts. One meaning relates to drinking a lot of tea, essentially related to experiencing strong effects from caffeine. There is definitely theanine in tea too, and other compounds that can affect your body and mental state, so it's not just caffeine, but it's mostly that. This kind of feeling is familiar to anyone who has drank a few cups of coffee in a short time, but it's not identical, because those other compounds really do alter the experience.

The next use and meaning relates to other compounds in tea combining with the caffeine and theanine effects to result in an atypical body feeling or mental state. In some description it's called cha qi, or what I take to mean the energy and feeling from tea, although that phrasing and implied meaning can lean towards mystical range a little. Per my experience this is a real thing. I don't tend to ever notice it unless I'm drinking sheng pu'er, and even then not so often. It's said that old tree and natural grown versions, or aged versions, can have a stronger effect, and there might be something to connecting those three inputs. It doesn't need to be regarded as a mystical theme, because it's well known that caffeine and theanine aren't the only two active compounds in tea, the only two that can potentially affect mental states.

You don't notice this much at all if you've eaten with or just before drinking the tea. My take on this, which isn't necessarily accepted conventional understanding, is that food slows the digestion of related compounds so that you are still absorbing and experiencing those inputs, but much slower, and it's the sudden change from one mental state to another that makes it so noticeable. At times it can feel like being stoned (a bit like on weed, just different), or very relaxed, or even hyper in unusual ways, all of which are also familiar ground for marijuana experience. I've drank tea that made me feel sleepy before, and have taken a nap after drinking a good bit of some.

So far nothing I've said is clearly supported beyond it being one more hearsay account, so let's consider what else is in tea that might account for this:

Tea Epicure article on tea chemistry

Tea leaves contain many amino acids, the most abundant of which is theanine. Theanine, specifically L-Theanine, is responsible for promoting alpha brain wave activity and a feeling of relaxation. L-Theanine in concert with caffeine can induce a state of “mindful alertness” in the tea drinker. Amino acids make up an average of 6% of the extract solids in steeped tea1...

The main methylxanthine in tea is the stimulant caffeine. Other methylxanthines found in tea are two chemically similar compounds, theobromine and theophylline. The tea plant creates these chemicals as a way to ward off insects and other animals. On average, methylxanthines make up 2% to 5% of the dry weight of the fresh tea leaves5. Methylxanthines also contribute to a bitter taste in the tea infusion. The level of methylxanthines in tea depends on the variety and cultivar of Camellia sinensis used, the climate, the age of the leaves, and the propagation method (seed vs. cutting) used on the plant...

Theobromine is also found in chocolate, and acts as a stimulant with similar effects as caffeine, seemingly just less intense (more on that here: https://neuropedia.com/theobromine-benefits-side-effects/). So there doesn't need to be any mystical explanation for why different types of tea have different effects on energy level and mood, even though we can't really completely unpack the total effect of all active compounds in tea, or map likely levels to tea types, since processing changes a lot beyond what that Tea Epicure article already cited.

Additional clarifications:

There's always more to add, so I'll extend those points just a little before closing.  

I didn't clarify that I always eat food before drinking tea, in part to offset the "tea drunk" experience, but really more to protect my stomach from either immediate or longer term negative impact.  I don't necessarily want to feel any sort of buzz or stony sensation from drinking tea, or to emphasize relaxed body-feel, and I couldn't be sure what the long-term effect on my stomach of drinking 8 to 10 grams worth of tea in daily sittings might be, so it works as a hedge of that risk to eat food first.  To me it seems to work best to eat something with both carbohydrates and fat in it, so fruit with toast and butter is fine, or breakfast cereal, or the heavier eggs, bacon, and rice breakfast (or the American version, with potatoes instead).

A separate line of thought, probably more common in sheng pu'er appreciation circles, is that "drinking tea with your body" is a higher form of experience, something people only come to value after long exposure and refined preference.  What to say about that?  I'm probably biased against wanting tea to affect me in related ways because I have some history with drug and alcohol use, not so much addiction and alcoholism, but enough that I don't want to revisit that path.

The sheng pu'er versions that affected me the most did match up with the hearsay input about what are said to, older tree plant material, natural grown versions, and those from regions that tend to be associated with that, like Lao Ban Zhang.  I've drank (and own) a significant amount of sheng aged from the early 2000s but I've not experienced much of the more prized 30 year old range, or well-regarded versions that stand out as most desirable related to tea enthusiast group hearsay.  It would be easier to isolate that kind of feel input if I was emphasizing it, not intentionally offsetting it related to eating food prior to drinking tea.

I don't tend to overdo it with tea quantity and caffeine input either.  I've accidentally gone there in the past, of course, during tasting sessions with others, or while writing comparison reviews of multiple teas.  It's not aversion to that effect that I avoid as much as making it a habit to moderate caffeine intake to prevent long term exposure problems.  I know of four people who have developed long term sensitivity to caffeine from drinking too much tea, three of them tea bloggers.  Two never did return to more moderate consumption, while after a substantial break two did.  

comparison tastings are likely to overdo it for caffeine intake

Caffeine can become a headache trigger, or can cause problems with maintaining balanced energy levels, beyond potential sleep disruption, or even more problematic disruption of normal sleep period rest cycles.  It's simple to avoid this potential risk, by staying at or below the standard daily recommended intake level for caffeine, 400 mg per day.  Using the standard amount of 30 to 50 mg of caffeine per cup it's no risk to drink eight 250 ml cups of tea a day, around two quarts or liters, and that's enough tea anyway.  It's possible to break that down to a finer level to dry leaf amounts, or to factor in body size and natural tolerance, raising or lowering that practical limit, but it's easy enough to limit yourself to that general range.

I think appreciating the first effect is fine, drinking types of sheng pu'er that lend themselves to that, and it would work to judge stomach impact risk by feel, if it causes discomfort (even though I don't; I stop short of needing to gauge that by preventing it).  For the second case getting relatively blasted on caffeine once or twice a week might still be fine, again even though I don't, but going further and further with exposure and daily intake habit seems like more of a concern.