Latvia's midsummer festival is a glorious, fire-lit, cheese-and-beer-fuelled marathon that runs from dusk to dawn. Here's what actually happens to your body across the Jāņi cycle — and how a little preparation makes all the difference.

For one night each June, Latvia refuses to sleep. Bonfires burn on hilltops, oak-leaf wreaths crown every head, caraway cheese and beer appear in quantities that defy explanation, and the whole country stays awake to greet a sunrise that arrives absurdly early. Jāņi is one of the oldest and most beloved celebrations in the Baltic calendar — and, from a purely physiological standpoint, one of the more demanding things we voluntarily put our bodies through all year.

It is also far older than it might feel. Jāņi is, at heart, a summer solstice festival — a celebration of the shortest night and longest day, marked across pre-Christian Europe long before it acquired the name of St. John (Jānis). On the night of June 23rd into the 24th, the sun in Latvia barely dips below the horizon, and the old belief held that this was the single most magical night of the year, when the boundary between the ordinary and the supernatural grew thin. Herbs gathered on Jāņi night — the famous Jāņuzāles — were thought to hold their greatest healing power, and ferns, according to legend, bloomed with a mysterious flower that only the luckiest couples wandering the forest at midnight could ever hope to find. (Botanically, of course, ferns don't flower at all — which has never stopped anyone from looking.)

The good news for the modern celebrant is that nearly every part of the Jāņi experience — the feast, the drinks, the sleepless night, the morning after — follows predictable biology. And once you understand the biology, you can work with it rather than simply suffering through it. Consider this a field guide to the longest night of the year, in three acts.

Act One: Before the Fire — Preparation

The single most useful thing you can do for a long night happens before it begins, and it's almost always neglected: you prepare the body that has to do the work.

The star of the Jāņi table — Jāņu siers, the golden caraway cheese — turns out to be a small masterpiece of intuitive food science. It is rich, fatty, and dense with protein, and that's not a flaw; it's an asset, if you time it right. Fatty and protein-rich food slows the rate at which the stomach empties into the intestine, which in turn slows the absorption of alcohol into the bloodstream [1]. The old folk instinct to "line your stomach" before drinking has a real mechanism behind it.

But the cheese hides a second, cleverer trick — and it's in the caraway. Those little crescent-shaped seeds are not merely for flavour. Caraway (Carum carvi) is, in the words of one herbal pharmacologist, among the most reliable of all the "carminative" herbs — plants that calm the gut and help expel trapped gas [2]. Its essential oils, principally carvone and limonene, have antispasmodic effects that relax the intestinal muscles, and clinical trials have found caraway oil — often paired with peppermint — effective against the bloating and discomfort of functional dyspepsia [3]. In other words, the ancestors who first folded caraway into a heavy festival cheese were, without knowing it, building a digestive aid directly into the richest food on the table. It is one of the most elegant examples of traditional Baltic cooking quietly solving a problem centuries before anyone could explain it.

There's a third, subtler piece of preparation worth knowing about. The liver carries the entire burden of processing alcohol, and it does so using enzyme systems that can be supported nutritionally in the days leading up to a heavy night.

Certain plants — among them the sharp, earthy black radish long used across Eastern Europe as a traditional liver and gallbladder tonic — contain glucosinolates shown in laboratory research to increase the activity of the liver's own phase II detoxification enzymes [4]. This is a gentle, preparatory idea rather than a quick fix: the kind of thing that belongs in the quiet days before the festival, not the chaos of the night itself. (It's the active principle behind earthy pressed juices like Sage Green's Earth Pulse.)

Act Two: The Long Night — The Feast and the Fire

Once the fire is lit, two things tend to challenge the body in parallel: the sheer volume of rich food, and the alcohol that accompanies it.

Take the food first. A night of grilled meats, šašliki, and slice after slice of caraway cheese is a heavy load for the digestive system, and the familiar result is bloating, heaviness, and sluggishness. This is where one of the best-evidenced plants in all of nutrition science earns its place at the table: ginger. A comprehensive systematic review of 109 randomized controlled trials found that ginger's benefits for digestive function, nausea, and inflammation were among its most consistently supported effects [5]. Ginger has been shown to accelerate gastric emptying and stimulate the stomach's natural contractions [6] — precisely the kind of help a Jāņi feast calls for. The traditional reach for something sharp and warming after a heavy meal was, it turns out, well-aimed. (Ginger reaches the modern table in warming blends like Sage Green's Golden Blend or as a concentrated ginger shot.)

It's worth pausing on the beer, too, because it is as woven into Jāņi as the fire itself. Latvia has one of the oldest unbroken brewing traditions in Northern Europe, and home-brewed Jāņi beer was historically a point of genuine pride — flavoured, in some regions, with the same kind of bitter and aromatic herbs that folk healers prized. Beer's reputation as the festival drink is no accident: in an era before refrigeration, fermentation was one of the safest ways to preserve the calories of the grain harvest. None of which changes the basic chemistry of what alcohol does once it's inside you — but it does explain why the mug in your hand carries several thousand years of history.

And here it's worth being honest rather than promotional. Nothing you eat or drink "cancels out" alcohol, lets you drink more safely, or prevents intoxication — the only things that truly help are drinking less, drinking slower, and alternating with water. What food and certain plant compounds can do is support the body's recovery from the oxidative stress that alcohol generates. When the liver metabolizes alcohol, the process produces a flood of reactive oxygen species and depletes the body's own antioxidant reserves, particularly glutathione [7]. This oxidative stress is one of the mechanisms now linked to how rough you feel the next day [8].

This is the genuine, evidence-based rationale for antioxidant-rich foods around a heavy night — not as a magic shield, but as recovery support. It's notable that one of the Baltic's own signature berries has been studied in exactly this context: a study found that anthocyanin-rich Aronia melanocarpa — chokeberry — helped counter alcohol-induced oxidative changes in the liver and reduced hepatic fat accumulation and inflammation in an animal model [9]. Aronia happens to be one of the most antioxidant-dense fruits that grows in the region. (It's the berry behind deep-purple juices like Sage Green's Moon Berry.) The same logic extends to vitamin-C-rich sea buckthorn, another northern berry whose dense bioactive profile has made it a long-standing folk remedy for general restoration.

The other quiet challenge of the long night is simple dehydration. Alcohol is a diuretic, the night is long, and the bonfire is warm. Much of what feels like a hangover is, in part, ordinary dehydration — which is why water, not another drink, is the single most useful thing to keep in hand as the fire burns down. There's a reason the tradition insists you stay awake until sunrise: the watching is the point. Pacing yourself so you can actually make it to dawn is, conveniently, the same thing your body would ask of you anyway.

Act Three: The Morning After — Recovery

Eventually the sun is fully up, the fire is embers, and the body presents its invoice. The morning after Jāņi is, for most people, a study in self-inflicted biology: a tired, dehydrated, inflamed system asking for repair.

The priorities that morning are unglamorous and effective. Rehydration comes first, because so much of the malaise is fluid loss. Gentle replenishment comes next — and this is where the same plants that helped during the night come back into their own. If nausea and a heavy stomach are the problem, ginger's well-documented anti-nausea and gastric-emptying effects are exactly what the morning calls for [5][6]. If the goal is simply to flood a depleted system with antioxidants and vitamin C, the region's berries — aronia, sea buckthorn — are among the densest natural sources available [9]. And the old European tradition of a "cleansing" spring tonic, nettle, brings a genuinely useful midsummer mineral profile of iron, calcium, and magnesium to a body that has lost a great deal overnight [10]. (Nettle survives today in pressed juices like Sage Green's Evergreen.)

There's a lovely symmetry here, too. Many of the herbs that Latvians traditionally gathered on Jāņi night — the Jāņuzālesbelieved to be at their most potent under the solstice sun — were precisely the bitter, aromatic, digestion-soothing plants that folk medicine reached for all year round. The festival that tests the body so thoroughly also gathered, in its own rituals, some of the very plants best suited to help it recover. The ancestors may not have had the biochemistry, but they had the pattern exactly right.

None of this is a cure for overindulgence. The only real cure is moderation and time. But supporting the body's recovery — fluids, gentle nutrition, antioxidants, rest — is both sensible and grounded in how the relevant biology actually works.

The Real Secret of Jāņi

Strip away the folklore and the festival reveals a surprisingly logical health arc: prepare the body beforehand, support digestion and counter oxidative stress during, and prioritise rehydration and gentle replenishment after. Latvians have intuited this rhythm for centuries — the caraway folded into the cheese, the warming herbs, the bitter solstice tonics, the insistence on water and wakefulness until dawn — long before anyone could measure glutathione depletion or graph gastric-emptying rates.

That's perhaps the most charming thing about Jāņi from a scientist's chair: it is a festival that has been quietly practising evidence-based wellness for a thousand years without ever calling it that. The fire, the cheese, the herbs, the wreaths — beneath the romance, there's a remarkably sound piece of folk physiology.

So light the fire, wear the wreath, and greet the sunrise. Just remember that the people who feel best on June 24th are rarely the ones who drank the most the night before — they're the ones who ate well, drank water, and gave their bodies a little help. Līgo!

This article is for general educational purposes and is not medical advice, nor an encouragement to consume alcohol. No food or drink prevents or reduces intoxication or makes drinking safe; if you choose to drink, do so responsibly, and never drive afterwards. Please consult a qualified healthcare professional about your individual situation.

References

1. Mayo Clinic / National Institute on Alcohol Abuse and Alcoholism (NIAAA). Food and the rate of alcohol absorption: the role of gastric emptying. (General consensus reference on food slowing alcohol absorption.)
2. Hobbs, C. Herbal Therapeutics: Caraway (Carum carvi) — carminative and antispasmodic properties. christopherhobbs.com.
3. Mahboubi, M. (2018). Caraway as an important medicinal plant in management of diseases. Natural Products and Bioprospecting, 9(1), 1-11. (Caraway oil with peppermint/menthol in functional dyspepsia and IBS.)
4. Hanlon, P. R., Webber, D. M., & Barnes, D. M. (2007). Aqueous extract from Spanish black radish (Raphanus sativus L. var. niger) induces detoxification enzymes in the HepG2 human hepatoma cell line. Journal of Agricultural and Food Chemistry, 55(16), 6439-6446.
5. Anh, N. H., et al. (2020). Ginger on human health: A comprehensive systematic review of 109 randomized controlled trials. Nutrients, 12(1), 157.
6. Nikkhah Bodagh, M., Maleki, I., & Hekmatdoost, A. (2019). Ginger in gastrointestinal disorders: A systematic review of clinical trials. Food Science & Nutrition, 7(1), 96-108.
7. Park, S. Y., et al. (2023). Combination of cysteine and glutathione prevents ethanol-induced hangover and liver damage by modulation of Nrf2 signaling in HepG2 cells and mice. Nutrients / PMC10604027.
8. Mackus, M., et al. (2020). The role of alcohol metabolism in the pathology of alcohol hangover. Journal of Clinical Medicine, 9(11), 3421.
9. Wang, et al., cited in Park et al. (2023): anthocyanin-rich Aronia melanocarpa ameliorates chronic alcohol-induced Nrf2 downregulation and inhibits hepatic fat accumulation and inflammation in mice. PMC10604027.
10. National Center for Biotechnology Information (PMC9413031). Stinging nettle (Urtica dioica L.): Nutritional composition, bioactive compounds, and food functional properties. PubMed Central.