jeffnv 10 hours ago

Noticing that the waist circumference on average went down on the peppermint group (85.17 -> 84.61) while the placebo group it went up (88.33 -> 88.65)? Also the resting heart rate dropped for the peppermint group. My initial suspicion is that the peppermint group coincidentally was also the 'got in better shape' group. Maybe the peppermint helped, but for relatively small groups that also seem to be improving waist circumference and heart rates likely due to good diet and exercise, I'm not convinced the peppermint did jack shit. More investigation needed! Would be awesome if it helped though!

  • rolisz 10 hours ago

    Maybe it helps with weight loss (I wish)

    • yumraj 9 hours ago

      It seems to aid in digestion, soothe upset stomach, so maybe it does.

  • potatoking 10 hours ago

    I'd think weight could be causal for hypertension result or sentiment over health measurement could have been causal for weight or the study could just be too small.

    • criddell 8 hours ago

      When you say weight, do you really mean obesity? And if you are talking about weight, is it likely that people who live in low gravity environments will have fewer hypertension problems?

      • debo_ 5 hours ago

        On the topic of mass, I am certain your pedantic comment will be mass downvoted.

  • ktm5j 9 hours ago

    But weight/mass didn't change one bit (okay exaggeration, but not by much), so maybe peppermint helps relieve gas. Who knows? There's a lot that this data could mean, and no simple way to figure it out.

    • bherms 7 hours ago

      i actually had heard it helps w/ bloating/stomach issues online and took for a while and def noticed a debloating effect and less gas... obviously 1 anecdote, but I'd assume any slight waistline reduction is due to that. Also sidenote: pooping often made it feel like I put a breathmint... up... "there" lol

      • samudrijan 7 hours ago

        Funniest thing today so far.

      • simondotau 7 hours ago

        Not surprising, it’s what happens to capsaicin too. Something has to happen to the molecules/compounds you consume. Either your body discards them, stores them, or transforms them.

        The fascinating part is that your anal tissue has that level of sensitivity and insight.

        • debo_ 5 hours ago

          Unlike the anuses in government etc.

      • scorpioxy 2 hours ago

        In my culture, that's the goto herbal drink for when you have a stomach ache due to indigestion or gas by the way. I don't know how or why they work but some of these things do work. The footnote here is that it is for pain/discomfort that would also go away by itself if untreated. It just speeds up the process and provides some comfort. For different kinds of pain/discomfort, a doctor needs to be consulted of course.

      • wahern 25 minutes ago

        Mint stimulates release of bile, which can help digestion, especially of fats. I have gallstones and unfortunately recently learned first hand how powerful the effect is after eating a couple of leaves (two kinds, but I forget which) from a neighbor's garden.

      • mindhash 18 minutes ago

        I thought on similar lines. Because I use it often for ibs i noticeably feel much better and I suspect the bp and heart rate reduction could be due to reduced gi effect on body

  • mlmonkey 8 hours ago

    Peppermint oil has traditionally been used in India for digestion, so you may be on to something. I remember this particular brand growing up: https://www.amazon.com/clp/B001NQ7S9G (no relation).

    • yumraj 4 hours ago

      I don’t think that’s peppermint. That’s pudina so spearmint. Mentha spicata.

  • vector_spaces 8 hours ago

    There has been some research on spearmint suggesting anti-androgen effects in PCOS, which is a bit unexpected to me as I wouldn't expect mint-family herbs to have much hormone modulating effect at all. I would imagine there to be similarities in profile between spearmint and peppermint so perhaps a related mechanism is involved, although I would probably expect the opposite outcome as a naive layperson. But I haven't closely evaluated the paper nor do I know whether there's been much else suggesting this

    It is important to remember that herbs are difficult to study in this setting compared with isolated compounds -- likely because their pharmacological and chemical compositions are sensitive to many factors: hour and season of harvest, form consumed (raw powder, alcohol extract, cold water infusion, fat emulsion, hot water infusion, combustion, pyrolysis, essential oil), part consumed (leaf, root, flower, seed), among staggeringly many others. Anyone with experience consuming cannabis or coffee can probably testify to the above

    Not to mention that the pharmacologically active compounds in many plants are far from being comprehensively understood, let alone their interactions and dynamics

    This isn't to say that every claim about herbs is to be taken seriously. My point here is more that there is no good reason to dismiss the herb itself as a cause yet simply because it's an herb and a fairly mundane one at that. There are easy examples of herbs which have pronounced physiological effects, used for recreation, performance enhancement, as literal poison, to induce labor, to thin the blood -- among others.

    https://pubmed.ncbi.nlm.nih.gov/19585478/

    • mrob 8 hours ago

      >I wouldn't expect mint-family herbs to have much hormone modulating effect at all

      Mints are closely related to pennyroyal (Mentha pulegium), which was traditionally (and dangerously because of toxicity) used as an abortifacient. Its mechanism of action is still unknown, so hormone modulating effects seem plausible to me.

      • samudrijan 7 hours ago

        Sit and drink pennyroyal tea, I’m anemic royalty.

      • rshm 7 hours ago

        Also used as lactation reducing herb.

      • vector_spaces 5 hours ago

        By "mints" I meant the family lamiaceae, so pretty broadly which contains sages, rosemaries, basils, teak, verbena, and in hindsight of course contains examples like this which straddle medicine (depending on dosage and circumstances -- I'm not advocating it be used as such) and poison. Even if just restricting to the genus mentha apparently. Anyway good call

    • r0ze-at-hn 7 hours ago

      So spearmint is not peppermint. Peppermint (mentha pipereta in this study) inhibits CYP3A4 and CYP1A2. CYP1A2 is in the liver and if that is inhibited then estrogen will route down the CYP1B1 path so the ratio of the two metabolites 2-OHE1 v.s 4-OHE1 would be altered. For the PCOS (renamed to PMOS btw) if they start with elevated 2-OHE1 after the peppermint this could result in improve estrogen signaling because the now raised 4-OHE1 has much higher affinity than the 2-OHE1 for ESR1 (Era). ESR1 in particular is known for lowering blood pressure.

      This particular path isn't that crazy, but it would only be for a subset of folk. From the study there is something simpler: menthol acts as a natural calcium-channel blocker, triggering vasodilation to reduce blood pressure.

  • f33d5173 8 hours ago

    Nothing but blood pressure and heart rate was significant, and heart rate only barely so. I wouldn't read anything into the other numbers. It was a 20 day study, you aren't going to get long term outcomes from that.

  • crooked-v 8 hours ago

    Wild-ass guess: maybe the aftertaste of peppermint oil twice daily leaves people who are already unhealthy wanting to snack less, leading to minor weight loss.

    • simondotau 7 hours ago

      As a bit of random speculation: improved digestion might reduce the “needy stomach” sensation associated with hunger.

  • joecool1029 4 hours ago

    I'm wondering if caffeine was accounted for in this. One thing I seem to recall is peppermint tea has some inhibition of CYP1A2. I notice it's missing from the wikipedia page now, so maybe this was a flawed study or something... figured I'd mention in case anyone else knows.

    At least this study says the activity was reduced, not significantly though: https://www.sciencedirect.com/science/article/abs/pii/S02786...

saulpw 7 minutes ago

Maybe we can add some licorice root to balance the effect.

jrflo 7 hours ago

Whenever I see a study like this I assume that the researchers won the p<0.05 lottery

yumraj 11 hours ago

There are two types of peppermint supplements being sold: mentha pipereta that this study looked at, and mentha arvensis.

I wonder if mentha arvensis has the same effect. Supplements vs mint tea would be another interesting thing to study in future.

  • kzrdude 9 hours ago

    Based on your new information, I think it would be good to test the effect of supplemenths vs supplemints.

    • tclancy 6 hours ago

      Please consider the fact there may be children reading before you do something like this again.

  • trueno 6 hours ago

    im bored and want to buy some peppermint sups. someone drop a brand and sell me on it in the marketplace of ideas

paimapi 5 hours ago

a single RCT of 40 people is about middle-of-the-range when it comes the hierarchy of evidence and is at best a 'that's neat, I'll wait a few years for there to be more studies' if you don't want to do any more thinking about it, a 'I need to see it in context of other studies' if you want a lot of work, or a 'I sure hope there's a meta/review' if you don't have the time but still want to remain skeptical

that said, there is a GRADE-assessed systematic review and meta on mint (PMC11587584) and this linked study's results are 7x the pooled effect size (SBP -8.5mmHg vs -1.2mmHg) of the other RCTs. the review also concludes that more high quality RCTs are needed before anything approaching clinical significance

the wildly disproportionate effect size indicates to me that this is one going to be one of those outlier studies that future reviewers will either likely omit or clearly state that it is an outlier result and if they're super duper honest they'll provide the new pooled results with and without this outlier study

_heimdall 2 hours ago

Peppermint is also very helpful for headaches and nausea in my experience. I'll smell some peppermint oil or put a drop on my upper lip, headaches and nausea go away pretty soon after.

1337h4xx 3 hours ago

Essential oils are quite versatile for self-experimentation; maybe one day the world will rediscover oilahuasca.

overtone1000 10 hours ago

That is very accurate sphygmomanometry!

profsummergig 5 hours ago

So does it therefore reduce stress? Anyone?

  • Finnucane 3 hours ago

    Those old York's Peppermint Patty ads were on to something.

reilly3000 7 hours ago

Aren’t people generally getting some via toothpaste?

  • simondotau 7 hours ago

    But do you spit or swallow?

    • garbageman 6 hours ago

      Whatever you want baby

      • Havoc 5 hours ago

        I need my porch painted and tradesmen are expensive

DonHopkins 10 hours ago

Doctor Bronner was right!

Peppermint - Pure-Castile Magic Soap: Cool, Refresh, and Awaken with Invigorating Peppermint

https://www.drbronner.com/products/peppermint-pure-castile-l...

Dr. Bronner invented the peppermint oil soap for soiled diapers

https://www.sandiegoreader.com/news/1978/nov/02/cover-look-f...

Created in California: How Dr. Bronner’s became the soap for every subculture

https://www.latimes.com/business/story/2023-07-12/dr-bronner...

>Perhaps inspired by that experimental ethos, customers have discovered their own unusual uses in the years since Emanuel started mixing gallons of peppermint castile soap out of his Pershing Square tenement apartment in 1948. [...]

>David, Mike and Lisa Bronner grew up in Glendale, not giving much thought to the prospect of one day taking over the family business and generally regarding their grandfather as a bewildering figure.

>“My granddad was always talking about uniting ‘Spaceship Earth,’ and it was kind of sailing over our heads,” David said.

>“He’d be talking to us as if we were all PhD students in religious studies,” Mike said of visits to Emanuel’s home when the siblings were in elementary school. “He was blind, and every once in a while he would say, ‘Are you there?’ and we’d be like, “All-one, Grandpa!’ And he’d be like, ‘Very good. OK, I want you to recite the peppermint bottle.’”

Lisa Bronner: The Poetry of the Lavender Label

https://www.lisabronner.com/the-poetry-of-the-lavender-label

>The label on the quart size of the Lavender Pure-Castile Magic Soap holds the greatest insight for me into his motivations and goals. The Peppermint label records the tenets of his Moral ABC, his guidelines for humanity to find unity and a path forward. But it is the Lavender quart that hosts his poetry, and in that I see his heart. [...]

>"To keep my health! To do my work! To love, to live!"

>"Great peace is found in little busyness."

>"Work well yourself and work for all."

>"Til we rally, raise, unite!"

>"All-One-God-Faith, All-One! Unite!"

>"Lives of great men all remind us we can make our lives sublime."

>"Life is real! Life is earnest! And the grave is not its goal."

>"Let us then be up and doing ... still achieving, still pursuing"

>"In all we do, let us be generous, fair & loving to Spaceship Earth and all its inhabitants."

>"We're ALL-ONE OR NONE! ALL-ONE!"

  • NDizzle 5 hours ago

    This is my favorite soap, by far, for what it’s worth. The peppermint one, in fact. ALL ONE!

Lu2025 7 hours ago

Well, mint tea does make me sleepy

alastairr 10 hours ago

Peppermint group N=20. Mkay. 2 of those lost to followup, one because they didn't like the taste (control group got peppermint cordial). The result might be real but needs followup before we all starting gulping down peppermint oil.

  • bryceacc 9 hours ago

    >50 µL of supplement diluted into 100 mL of water

    pretty tiny amount of peppermint was consumed

    • jeffbee 9 hours ago

      That's enough to turn a whole barrel of water detectably minty.

    • HeyLaughingBoy 8 hours ago

      I was surprised by this too. From a background in writing code to control precision pumps, I have a good idea of what 50 µL looks like and it seemed like an awfully small amount. But I don't know how concentrated the oil is.

      FWIW, I had an Indian co-worker who took peppermint oil frequently and said that it was very good for his upset stomach.

catigula 7 hours ago

The funny thing is, I've read countless meta-analyses on various mainstream drugs, where total n=hundreds of thousands, and I still don't know if they work at all or not.

techteach00 8 hours ago

Also works well for IBS. Popular brand name green box. Bit pricey.

Palomides 9 hours ago

HN really upvotes some dumb medical articles, come on, n=20 about peppermint?

  • rozap 9 hours ago

    Silence, we have disruptive direct to consumer peptide startups that need to pump.

  • ChickeNES 8 hours ago

    From PLOS One as well! I remember in college, I was taking a bio class that taught how to read journal articles...and a psych class that was assigning them. Psych class assigned almost solely PLOS One articles...which didn't survive the criticism I was being taught in the bio class lmao

  • pessimizer 8 hours ago

    If there's anything consistent about HN as long as I've been on it, it's that HN is orthorexic.

    • doublepg23 7 hours ago

      > orthorexic

      New word of the day!

liveoneggs 9 hours ago

herbal tea is good for you, it seems

  • SwellJoe 7 hours ago

    This study did not involve tea. Do you have links to studies showing herbal tea has similar effect? (Sincere question, I drink a lot of peppermint tea for its mild decongestant effects.)