Matcha and collagen: what the studies measure
Matcha and collagen: what is published and what is not
The short answer, for anyone who only wants that: no clinical trial in people has measured collagen synthesis after drinking matcha or green tea. What is published covers attention, sleep, mood, blood lipids and photoaged skin. None of those trials measured collagen. Every study named below carries its PMID so you can check it.
What matcha is
Matcha is green tea ground to a very fine powder. The plant comes from China and the whisked preparation became known through Japan. The obvious markers are the bright green colour and the dense, faintly sweet flavour.
Unlike an infusion, you drink the whole leaf. The powder is whisked into water and nothing is filtered out, so the catechins, theanine, caffeine, chlorophyll and fibre end up in the bowl rather than only the soluble fraction.
What collagen is
Collagen is a structural protein and the most abundant one in the human body. It makes up a large part of skin, tendons, ligaments and cartilage. Natural production declines with age, which shows up first in the elasticity of the skin.
The two skin trials and what they measured
We looked for human trials linking green tea or matcha to collagen synthesis and found none. The nearest are two studies on photoaged skin, and it is worth reading what they recorded.
The first appeared in Dermatologic Surgery in 2005 (Chiu et al., PMID 16029678). Forty women with moderate photoageing were randomised to eight weeks of a 10% green tea cream plus 300 mg orally twice a day, or to placebo. Clinical assessment showed no significant differences, though the biopsies did show a higher elastic tissue content.
The second appeared in the same journal in 2009 (Janjua et al., PMID 19469799). Fifty-six women aged 25 to 75 took 250 mg of oral green tea polyphenols twice a day for two years. The authors conclude that at 24 months the supplementation was no better than placebo.
What has been measured, and in whom
A randomised placebo-controlled trial published in Nutrition Research in 2021 (Baba et al., PMID 33744591) gave 2 g of matcha a day for two weeks to 42 adults aged 25 to 34 and recorded their Stroop test reaction times after a mild stress task.
A twelve-month trial published in PLoS One in 2024 (Uchida et al., PMID 39213264) followed 99 older adults with cognitive decline, 49 on 2 g of matcha daily and 50 on placebo. The primary outcome, the Montreal Cognitive Assessment, did not change significantly.
Caffeine: a figure from composition, not from an effect
For matcha as a category, the USDA nutrient database gives 2.4 g of caffeine per 100 g of powder. A bowl made with 2 g therefore carries around 48 mg, roughly half a cup of filter coffee. That is a composition figure and says nothing about what it does.
Our own powder has its own analysis, datasheet MZ-FT-MAT-CER-001, at 3.2 g per 100 g. The two numbers are not interchangeable: one describes the category, the other one batch.
So why do the two keep turning up together
Because they share a shelf. In Holland & Barrett, and in the wellness aisle at Waitrose, collagen powder and matcha sit about twenty centimetres apart, and a good share of those collagen tubs are matcha flavoured. Shelf adjacency is merchandising, not evidence. Pay £29 for a tub of collagen powder flavoured with matcha and you are mostly buying the flavouring, in its weaker form.
How to tell good matcha from the rest
Colour first. Fresh first-harvest leaf grown under shade gives a bright jade green, while older or coarser stock looks olive or straw-coloured. Then the grind: properly milled powder feels like face powder between the fingers, not like flour. Then the smell, which should be sweet and grassy rather than hay-like.
Our Matcha Zen Ceremonial is first harvest, shade grown in Jingshan (China), processed at Zhejiang Camel Transworld in Yuhang (Hangzhou) and stone milled slowly. 100 g for £19.00, about 50 bowls. A matcha latte at Pret costs roughly what a week of the powder costs at home, which is one way to find out how much you value the walk.
If you want to know how much makes sense in a day, that is covered in our piece on daily amounts.
References
- Chiu AE, Chan JL, Kern DG, Kohler S, Rehmus WE, Kimball AB., Double-blinded, placebo-controlled trial of green tea extracts in the clinical and histologic appearance of photoaging skin. Dermatologic Surgery, 2005. PMID 16029678. https://pubmed.ncbi.nlm.nih.gov/16029678/
- Janjua R, Munoz C, Gorell E, et al., A two-year, double-blind, randomized placebo-controlled trial of oral green tea polyphenols on the long-term clinical and histologic appearance of photoaging skin. Dermatologic Surgery, 2009. PMID 19469799. https://pubmed.ncbi.nlm.nih.gov/19469799/
- Baba Y, Kaneko T, Takihara T., Matcha consumption maintains attentional function following a mild acute psychological stress without affecting a feeling of fatigue: A randomized placebo-controlled study in young adults. Nutrition Research, 2021. PMID 33744591. https://pubmed.ncbi.nlm.nih.gov/33744591/
- Uchida K, Meno K, Korenaga T, et al., Effect of matcha green tea on cognitive functions and sleep quality in older adults with cognitive decline: A randomized controlled study over 12 months. PLoS One, 2024. PMID 39213264. https://pubmed.ncbi.nlm.nih.gov/39213264/