Leah:
Hello and welcome to the Ideal Nutrition Podcast. I’m Leah Higl and I’m here with my co-host Aidan Muir and today we will be talking about a supplement called L-Theanine. So L-Theanine itself is an amino acid that is naturally found in plants. So we do and can naturally consume it through different kinds of tea, although the amount in there is a lot lower than what we kind of see in research looking at L-Theanine and its potential benefits.
So we’ll talk about kind of other ways of taking it as well. But it theoretically helps with relaxation by increasing alpha waves in the brain amongst other things. So I know it’s something that you’ve been looking into a fair bit as of late and that’s something that can be potentially quite interesting when we’re looking at maybe stress and anxiety and but we’ll talk about what its potential effects are, dosages and maybe some potential side effects as well.
Aidan:
So the biggest one is a reduction in stress. There are a bunch of randomised control trials that show L-theanine helps with stress. We’ve linked them in the show notes. Normally I’m a lot more nuanced when talking about research and stuff like that. But the reason I’m keeping this section short and sweet is because of all the randomised control trials that have been done on this topic to the best of my knowledge, they have all shown benefits from proving stress levels. Like this is a clear cut thing. The only thing that you could argue is that maybe there’s not enough studies, maybe there’s not enough sample size.
But it’s like, if we’re at a point where there’s five plus randomised control trials and every single one shows reductions in stress and like how much more do we really need before we’re confident in that topic? starting with stress, I think that’s pretty clear, cut.
Leah:
Yeah, I guess it’s just how much it improves stress by that might be the thing that we’re still kind of questioning, right?
Aidan:
Yeah. And it’s not like, this is a clear thing. It’s not a game changer that like dramatically shifts things. Call it a 20% improvement. Like I know I’m that number out of thin air because it’s kind of like a lot of this research is based on like, how do we measure stress? It’s self-reported, right? So we could see like a 50% improvement in self-reportable levels of stress and I’ll just downplay it by calling it a 20%. But it’s like, how much does it do? Like it depends on your baseline levels. It depends on a variable so it’s hard to give a good number but it does help consistently.
Leah:
Yeah I think the the place where it’s less clear is probably around that anxiety point of view so stress and anxiety, people do tend to link those together and just call it stress and anxiety. But I think it’s an important distinction to make where we do see pretty clear benefits of L-Theanine in stress, but less so with anxiety. So a 2016 systematic review on the impact of L-Theanine on stress and anxiety found five randomised controlled trials. And one of them actually included people with diagnosed anxiety, which is an important thing because a lot of the research that looks at anxiety doesn’t involve people with anxiety.
Aidan:
Yeah, it’s wild.
Leah:
So that’s a bit of an issue. But the specific one that did include people with diagnosed anxiety did not find any advantages of L-Theanine over placebo for specific anxiety outcomes. Like the research that did find improvements in anxiety, whilst that looked pretty promising and it’s worth being aware of, it’s not particularly relevant because again, those participants were not diagnosed with anxiety. So how much can we actually draw from that when it comes to anxiety? The study that include people with the diagnosis didn’t find any beneficial outcome.
Aidan:
Yeah, I think it makes sense to keep an open mind on this, but it also would be silly to say L-thin helps with anxiety. It’s very early days there. And it’s like if we had two or three studies with people with anxiety and L-theanine in showing no improvements, at that stage, we start to get pretty clear being like, okay, this doesn’t help anxiety.
Leah:
But just having one, know, it’s still a little bit in the air.
Aidan:
It’s still a little bit in the air.
Leah:
Yeah. And I think even still, looking at if there’s a reduction in stress potentially that does have a flaw and effect to anxiety even though they are different. So I think it’s something worth considering but it’s just not as clear cut in that space.
Aidan:
That’s why I it makes sense to be open minded about it. Another interesting topic is sleep. I’ll look at this from two angles. So the first angle is just helping you sleep at night. L-Theanine does not directly affect sleep. Indirectly though, it could benefit sleep through reducing stress and anxiety. And I’m not just saying that because it makes sense, because it does make sense, but that’s what the research finds. The research finds that most people who take L-Theanine get better sleep, largely due to the reductions in stress slash maybe anxiety. I’ve linked some of that research in the show notes. Some of it is looking at sleep directly, some of it is just looking at stress, and then they’ve also measured sleep and they’ve shown improvements in sleep.
There is also one study in particular that is on children with ADHD that found taking 400 milligrams of L-CNN, which is a relatively high dose, but not super crazy. Taking 400 milligrams of L-CNN per day, it improves their sleep and you could make some logical sense about maybe this could help ADHD due to that. But the other angle I want to look at this through is something that I see more on social media more so than the research. There’s not really research looking at this because researchers don’t really want to spend time on this. I’ll go through it.
The concept of a lot people saying that they like, take L-theanine and then I feel drowsy during the day. I’ve seen a lot of people say that and I want to analyse it from a few perspectives. One is open-minded perspective, maybe they are experiencing this. The other is let’s look at it from another angle. The other angle to start off with is to really test this we need to compare it to placebo because a lot of people would feel a reduction in stress as being tired in some cases.
Leah:
Yeah, that’s true.
Aidan:
Yeah, and I do wonder like does stress make people more don’t know like alert is the right word.
Leah:
If you’re in fight or flight mode compared to being at like baseline.
Aidan:
What if you have relatively subpar sleep to start off with, but then you’re just stressed all day, every day, and then suddenly stress is down a little bit. Do you feel a little bit more drowsy? And then the other thing is like the impact of, as we said, placebo. Like some people might do that. So like the only way we can really measure that is by comparing to placebo and then if people still experience that, then I’d fall on that latter kind of thing. So once again, open-minded, but like if we’re gonna, if I was gonna give a simple cover-all statement, it is that L-theanine does not affect sleep during the day directly, but the open-minded perspective is like, what if somebody experienced less stress and they were carried over? Maybe.
Leah:
Yeah. Another potentially useful application for L-Theanine is utilising caffeine and L-Theanine together as a combination. So caffeine obviously helps with focus and productivity. That’s why many of us use it, but it can come along with some negative side effects like increased heart rate, increased blood pressure, jitters, increased anxiety, and so things that are not super conducive to productivity and don’t feel great. But if we look at L-Theanine,
L-Theanine has evidence it can potentially offset some of those specific things. So utilising the combination of the two could be beneficial for reaping the rewards of caffeine whilst dulling its negative side effects. So I think that could be an interesting way to utilise L-Theanine.
Aidan:
And it is pretty commonly used, a lot of people do notice benefits with that. I’m a lot higher on the benefits of like the caffeine associated anxiety and L-Theanine offsetting that, then I am so much on the just helping anxiety. Generalised anxiety. Yeah. I see far more potential there. But like we clearly do see that like the increased heart rate and the jitters and stuff like that is reduced when people take L-Theanine. So that’s pretty promising.
An obvious question that you might have is what are the downsides? Are there any side effects or anything like that? And there are no common side effects that are reported, which I don’t want to like, I always feel very cautious making a blanket statement like that because it’s like, what if there is a super rare thing that happens and somebody’s like, you said there were no side effects ever. I found a case study. I don’t know. So like there are no common side effects reported.
If you want another level of detail that could make you feel far more comfortable taking the common dose that we’ll recommend, the common dose, which we’ll talk about a bit more, but like it’s 200 to 400 milligrams, right? One study on rodents even used a crazy high dosage of 4,000 milligrams per kilo. I can’t remember if it’s on my head, but I looked up right after reading the study and be like, how much does a rodent normally weigh? It’s somewhere between, I think it’s somewhere between like 200 and 500 milligrams. So like, call it half a kilo, so like we’re looking at still over 2000 milligrams or around 2000 milligrams, don’t test my maths on that. So 2000 milligrams per day for a tiny, tiny rodent for 13 weeks and no down sides found.
And we’re like, okay, well, I’m not a rodent. l Iike to think a little bit bigger. if I’m looking at 200 to 400, that’s like nothing in comparison to the obscene amount that was dosed for that particular study.
Leah:
And talking a little bit more about the dosages. So 200 milligrams per day appears to be the most common dosage. But like you said, 200 to 400 milligrams is kind of the range. It is safe to go higher than that from what we can see based on those rodent studies, but we aren’t exactly sure how high you could go before there are any risks. there’s probably, it’s probably just worth staying within the recommended dosage range.
Aidan:
I just look at it through the lens of being like, if we see this working consistently in research. And we don’t have a lot research testing orders on higher. Let’s just do what we’ve seen works.
Leah:
Yeah. And if there are beneficial outcomes, yeah, two to 400 milligrams, and we know that’s safe, I think that’s probably like where you want to sit anyway. It does take 30 to 50 minutes to peak in the blood and has a half life of anywhere between 58 to 74 minutes. So I would dose it accordingly based on when you want the stress reducing effects, which could be, you know, using your caffeine, L-Theanine combo or it could be a time where you know stress is going to be quite high in the day but yeah a lot of applications for it.
Aidan:
Yeah when people ask me like when should I take it like as said, the caffeine, L-Theanine combo. The other option is like an hour before bed or something like that is another option. And another one that I love in theory, but would be very hard to do is like an hour before the most stressful part of the day. But it’s like, I don’t know, once you get to that level of detail, are you going to take it consistently? I never actually recommended that way just because it’s like, well, it’s probably not going to happen in practice. People are going to forget to take everything like that. But in a perfect world. that’s when you would take it.
Leah:
Yeah, and could you potentially take it multiple times a day?
Aidan:
You can, I haven’t seen research on that. that would be an interesting thing to kind of test. Yeah, and that’s where I come back to being like, if we 200 milligrams works, it’s like, maybe you could take it multiple times a day. I’m pretty open to that. I don’t see any downside of it. It’s just, once again, we haven’t seen whether that works.
Leah:
Yeah, interesting. So this has been episode 102 of the Ideal Nutrition podcast on L-Theanine. If you haven’t left a rating and review, as always, that’s always greatly appreciated. But otherwise, thank you’re pitching me.