• dohpaz42
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    8 days ago

    You’re right, and unfortunately it’s also difficult to find a good quality coffee that’s Fair Trade too.

    Theanine? What’s that do?

    • unfortunate_ferret@piefed.ca
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      8 days ago

      Indeed… Sounds like an unfilled niche, when you put it all together like that 🤔

      Anyhoo. l-Theanine is one of the active ingredients in various teas, alongside caffeine, and complements the effects of caffeine while also offering neuroprotective effects. You’ll find it in coffee too, but only in trace amounts, where in tea it’s a lot closer to 1:1 (variable by botanical of course). Some light reading I happened across in my excursions:

      And, this is a very long-term study - it’s more about the other compounds in coffee and tea than the caffeine and theanine, but it’s a good read and at least tangential to your question: https://pubmed.ncbi.nlm.nih.gov/39772974/

      There’s also this meta-study I found while I was looking for the first one, which shows the benefits differ somewhat based on physiology: https://pubmed.ncbi.nlm.nih.gov/37523229/

      I hope that answers the question 😂

      • dohpaz42
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        8 days ago

        Damn. That is the best response I could have asked for. Thanks!

      • SaveTheTuaHawk@lemmy.ca
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        8 days ago

        Just FYI: all those studies are poorly controlled, underpowered and typical of the junk science around supplements.

        • unfortunate_ferret@piefed.ca
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          7 days ago

          Fair cop on some of it, but some I will defend, and the wider point holds. At supplement doses theanine alone has a narrow but consistent effect on reaction time; paired with caffeine it does more, across attention more broadly. Moderate effects, not miracle ones, but they replicate across independent meta-analyses, which is more than most of the supplement aisle can say.

          Binning, and cheerfully:

          And two of mine, while I’m at it:

          • The 1:1 ratio was wrong, I misremembered. The actual tea arms in the meta-analysis below come in at 46 mg theanine to 100 mg caffeine, 67 to 136, 17.5 to 87. So 1:2 to 1:5 depending on the leaf (variable by botanical, as I said).
          • “Neuroprotective” was an overclaim. That traces to rodent focal ischaemia models: https://pubmed.ncbi.nlm.nih.gov/17928735/ - not human data.

          Not binning:

          Those links were what I’d happened across, not a curated evidence base, and I never claimed the list was exhaustive. A weak cite doesn’t kill a claim, it just means I grabbed badly off the shelf. The claims themselves hold up in much better-conducted work:

          • Cognitive and affective effects of L-Theanine: a systematic review and meta-analysis of 31 randomized trials (Mol Psychiatry, 2026, n=1168): https://www.nature.com/articles/s41380-026-03727-9 - single 200 mg dose, 30 to 60 min before testing, improved choice reaction time, SMD 0.51 (95% CI 0.25 to 0.77). No serious adverse events across the lot. Caveat: senior author founded a supplement company.
          • Effects of Tea or its Bioactive Compounds l-Theanine or l-Theanine plus Caffeine on Cognition, Sleep and Mood (Nutrition Reviews, 2025, 49 RCTs, 15 pooled): https://academic.oup.com/nutritionreviews/article/83/10/1873/8123998 - theanine alone improves choice reaction time (SMD -0.35, CI -0.61 to -0.10, about 18 ms) and does close to nothing on simple reaction time, digit vigilance or accuracy. The combination with caffeine is where the wider effects are: attention switching accuracy SMD 0.40 (0.24 to 0.57) in the first hour, digit vigilance accuracy 0.20 (0.02 to 0.38) in the second. Caveat: two of five authors are Lipton Teas and Unilever, and admittedly the industry was the single most common funding source across the included trials. Though, that doesn’t invalidate anything on its own, either.
          • Acute effects of tea constituents L-theanine, caffeine and EGCG on cognitive function and mood (Nutr Rev, 2014): https://pubmed.ncbi.nlm.nih.gov/24946991/ - the original combination meta-analysis, moderate effects on alertness and attention switching in the first two hours.

          Also, “underpowered” is the wrong stick for two. The Saku cohort (https://pubmed.ncbi.nlm.nih.gov/39772974/) is 1155 people followed about fifteen years, and Zhu 2024 (https://pubmed.ncbi.nlm.nih.gov/37523229/) pools 33 studies and 389,505 participants. Their weakness is that they’re observational: food frequency questionnaires, healthy-user confounding, and pooling observational studies pools the confounding rather than cancelling it. Real problem, different problem, and I’d rather be criticised for the one I’ve actually got thank you very much.

          The curling study (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10566444/) is n=22 but crossover, which brings more power per subject than the raw number suggests. Narrow population and sports nutrition has a publication bias issue, but it isn’t junk.

          So. The acute attention effects at supplement doses are real, hold up across independent meta-analyses, and are stronger with caffeine than without. Sleep and relaxation effects are not as concrete as the marketing suggests. Neuroprotection is rodent focal-ischaemia models, and that class of result translates to humans badly (if there’s human evidence I haven’t found it). Worth being clear as well that the cohorts above don’t necessarily fill that gap: they measure tea and coffee drinking, not theanine intake, so anything they find could be catechins, chlorogenic acids, the sort of person who drinks green tea, etc.

    • YellowParenti@lemmy.wtf
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      8 days ago

      It’s in tea. Its added to energy drinks cause it helps with the caffeine jitters. It helps smooth things out so you don’t feel like you’re having a panic attack like pre workout does to some ppl.