Hops are the flowers, or strobiles, of the hop plant (Humulus lupulus). The hop plant is a perennial climbing plant native to Europe, Western Asia, and North America, with different cultivars and varieties specific to each region. Properly named a bine, as the plant supports its growth solely by the strength of its stems and without the need for tendrils, it can grow to 30 feet long, with square bristled stems and hairy lobed leaves, and dies back to a rhizome in the autumn each year.
The hop flowers are drooping and yellow-green, and have a star-shaped appearance when open. The hop plant is part of the Cannabaceae family, and is related to hemp and marijuana. Hops are most commonly used as preserving and flavoring agents in beer, as the characteristic bitter taste of hops cuts the sweetness of the malted cereal. Major hops-producing regions include Germany, the United States, and Ethiopia. In addition to their use in brewing, hops are considered to have medicinal benefits in various alternative medicinal traditions, and are used to promote relaxation and to stimulate the appetite.
Though today hops are associated almost exclusively with beer-making, hops were absent for much of beer-making’s history. The first recorded evidence of beer comes from hunter-gatherer societies approximately 9000 years ago. Hops, on the other hand, were first recorded by the Roman naturalist Pliny the Elder in 77 AD, and he said nothing of their use in beer. Instead, he spoke of the plant as a botanist would, noting its stiff stems and relation to other climbing vines and calling it an “amusement” rather than food.
The first recorded evidence of hops being used in beer comes from France in 822 AD, and Germany did not start using hops in beer until the 12th century. Prior to hops, a mixture of fruit and spices called “gruit” was used for the same purpose. Even after the introduction of hops, gruit remained the most common flavoring ingredient in many countries. In fact, for centuries England insisted on a distinction between “ale,” which had to be flavored with gruit, and “beer,” which could use hops. Only in the 19th century did this distinction dissolve, and hops replaced gruit entirely soon after. Nowadays, beer is almost exclusively flavored with hops.
In contrast to their relatively new introduction to beer, hops have been used for their medicinal purposes for centuries. European folk medicinal traditions hold that hops have sedative powers, and pillows stuffed with hops were often used by those who wanted a restful night’s sleep. In fact, King George III was said to sleep on hop pillows, and at least one London doctor recommended hop pillow for those suffering from anorexia and other nervous disorders. Tinctures or infusions were used to help stimulate the appetite and treat digestive problems, and a mixture of hops and chamomile was used externally as an analgesic. Hop tea, or even beer, was also prescribed to prevent or slow hair loss, and the young shoots, which are also edible, were used to purify the liver, spleen, and blood. However, herbalists recommended caution, as it was believed that too high a dosage of hops would lead to melancholy.
The name “hops” comes from the Anglo-Saxon word hoppan, meaning “to climb.” The Latin name, Humulus lupulus, was given by Carl Linnaeus. The genus name, Humulus, comes from humle, the Swedish name for the plant. The species name, lupulus, meaning “wolf,” comes from the writings of Pliny the Elder, who referred to the plant as “willow wolf” because of its tendency to climb trees and strangle them in the process, much as a wolf strangles a sheep.
Hops are most commonly known as the main flavoring and preservative agent in beer. They have a characteristic bitter flavor, which cuts the sweetness from the malted cereal. The young shoots and leaves of the plant are also edible, and are sometimes eaten as vegetables. Pliny the Elder mentioned that the young shoots can be eaten like asparagus, indicating that they were a fairly common vegetable in ancient times, but nowadays hop shoots are not widely consumed.
Hops have been used for their medicinal purposes for centuries. The most common use of the plant is as a sedative, for which it was made into pillows by European folk medicinal practitioners. Interestingly, this alleged benefit of the plant seems to be widespread, with mentions of hops used as a sedative in the writings of Arabic physicians and among the Cherokee of North America, suggesting hops were used for sedative purposes in many distinct cultures across the world.
Scientific research has suggested that hops do have decided sedative properties. A study performed in quail found that hops preserved the circadian rhythm and reduced nocturnal activity, while a study performed in rats concluded that hops extract had a stronger effect than Diazepam, a commonly-prescribed sedative 1, 2. Rodent studies have suggested different mechanisms by which hops may be inducing sleep, such as activating the melatonin receptors 3 and altering GABAergic neurotransmission 4. Interestingly, studies have indicated that the alpha-acids present in hops, which are responsible for their bitter flavor, also contribute to their sedative effect, and may also have anti-depressant properties 8. Clinical trials have mostly tested a combination of valerian and hops instead of hops alone, but these trials have also generally concluded that this valerian-hops combination significantly induces sleep compared to placebo 5-7. While the clinical evidence is still somewhat lacking, it seems likely that hops, especially in combination with valerian, can promote restful sleep, possibly through a number of different mechanisms, and may also have some anti-depressant activity.
In addition to their alleged sedative properties, hops have also been suggested to be effective in fighting cancer, specifically due to a compound called xanthohumol. Xanthohumol has been proposed to have anti-cancer activity via a number of different mechanisms, including the inhibition of carcinogen-synthesizing enzymes and inhibition of tumor growth, both seen in cell culture models 9, 10. However, the level of hops in beer is generally considered too low to produce any anti-cancer effects, and no clinical trials have been done in this field, limiting knowledge of this anti-cancer effect in humans 11. Thus, while hops are considered safe to use 5, 11, more research needs to be done into their alleged anti-cancer effects to determine their efficacy and therapeutic potential in that area.
1. Franco L, Sanchez C, Bravo R, et al. 2012. The sedative effect of hops (Humulus lupulus), a component of beer, on the activity/rest rhythm. Acta Physiologica Hungarica 99(2): 133-139.
2. Shishehgar R and A Monadi. 2013. Study of sedation and pre-anesthetic effects of polar, semi-polar, and non-polar fractions of hop (Humulus lupulus L.) extract compared with Diazepam in rats. Middle-East Journal of Scientific Research 16(6): 762-768.
3. Butterweck V, Brattstroem A, Grundmann O, et al. 2010. Hypothermic effects of hops are antagonized with the competitive melatonin receptor antagonist luzindole in mice. Journal of Pharmacy and Pharmacology 59(4): 549-552.
4. Zanoli P, Zavatti M, Rivasi M, et al. 2007. Evidence that the beta-acids fraction of hops reduces central GABAergic neutrotransmission. Journal of Ethnopharmacology 109(1): 87-92.
5. Koetter U, Schrader E, Kaufeler R, et al. 2007. A randomized, double blind, placebo-controlled, prospective clinical study to demonstrate clinical efficacy of a fixed valerian hops extract combination (Ze 91019) in patients suffering from non-organic sleep disorder. Phytotherapy Research 21(9): 847-851.
6. Ross SM. 2009. Sleep disorders: a single dose administration of valerian/hops fluid extract (Dormeasan) is found to be effective in improving sleep. Holistic Nursing Practice 23(4): 253-256.
7. Morin CM, Koetter U, Bastien C, et al. 2005. Valerian-hops combination and diphenhydramine for treating insomnia: a randomized placebo-controlled clinical trial. Sleep 28(11): 1465-1471.
8. Zanoli P, Rivasi M, Zavatti M, et al. 2005. New insight into the neuropharmacological activity of Humulus lupulus L. Journal of Ethnopharmacology 102(1): 102-106.
9. Miranda CL, Yang Y-H, Henderson MC, et al. 2000. Prenylflavonoids from hops inhibit the metabolic activation of the carcinogenic heterocyclic amine 2-amino-2-methylimidazo[4,5-f]quinoline, mediated by cDNA-expressed human CYP1A2. Drug Metabolism and Disposition 28(11): 1297-1302.
10. Deeb D, Gao X, Jiang H, et al. 2010. Growth inhibitory and apoptosis-inducing effects of xanthohumol, a prenylated chalone present in hops, in human prostate cancer cells. Anticancer Research 30(9): 3333-3339.
11. Stevens JF and JE Page. 2004. Xanthohumol and related prenylflavonoids from hops and beer: to your good health! Phytochemistry 65(10): 1317-1330.
Species: H. lupulus
Alleged Medicinal Uses –
Anaphrodisiac, Anodyne, Antiseptic, Astringent, Boil, Cancer, Cystitis, Debility, Diuretic, Dyspepsia, Fever, Hypnotic, Inflammation, Nerves, Nervine, Poultice, Rhematism, Sedative, Soporific, Stomachic, Sudorific, Tuberculosis, Tumor, Vermifuge
Active Ingredients –
1,2-EPI-THIOHUMULENE; 12AROMADENDRINE-EPOXIDE; 2′,6′-DIMETHOXY-4,4′-DIHYDROXY-CHALCONE; 2,2-DIMETHYL-5-OXO-2,5-DIHYDRO-FURAN; 2,3,4-TRITHIAPENTANE; 2,3,5-TRITHIAHEXANE; 2-DECANONE; 2-DODECANONE; 2-METHYL-5-PENTENYLFURAN; 2-METHYL-BUT-3-EN-2-OL; 2-METHYL-BUT-B-EN-2-OL; 2-METHYL-BUTYL-2-METHYL-BUTYRATE; 2-METHYL-BUTYL-ISOVALERATE; 2-METHYL-PROPAN-1-OL; 2-METHYL-THIA-5-HEX-2-ENE; 2-METHYLBUTYLHEPTANOATE; 2-METHYLBUTYLHEXANOATE; 2-METHYLBUTYLISOBUTYRATE; 2-METHYLBUTYLPROPIONATE; 2-METHYLPROPYL-2-METHYL-BUTYRATE; 2-METHYLPROPYL-ISOBUTYRATE; 2-METHYLPROPYLPENTENOATE; 2-NONANON; 2-PENTADECANONE; 2-TETRADECANON; 2-TRIDECANONE; 2-UNDECANON; 3′(ISOPRENYL)-2′,4′-DIHYDROXY-4,6′-DIMETHOXY-CHALCONE; 3-(4-METHYL-PENT-3-ENYL)-3-THIOPHENE; 3-METHYL-BUT-2-EN-1-AL; 3-METHYL-BUTAN-1-OL; 3-METHYL-BUTAN-2-ONE; 3-METHYL-BUTANOIC-ACID; 3-METHYLBUTYLISOBUTYRATE; 4,5-EPITHIOCARYOPHYLLENE; 4-(4-METHYL-PENT-3-ENYL)1,2-DITHIACYCLOHEX-4-ENE; 4-(4-METHYL-PENT-3-ENYL)3,6-DIHYDRO-1,2-DITHIINE; 4-DEOXYCOHUMULONE; 4-DEOXYHUMULONE; 5-(4-METHYL-5-PENT-3-ENYL)1,2,3-TRITHIACYCLOHEPT-5-ENE; 5-ALPHA-ERGOSTAN-3-ONE; 5-ALPHA-STIGMAST22-EN-3-ONE; 5-ALPHA-STIGMASTAN-3-ONE; 6-(4-METHYL-PENT-3-ENYL)1,2,3,4-TETRATHIACYCLOCT-6-ENE; 8,9-EPI-THIOHUMULENE; ACETONE; ADHULUPONE; ADHUMULONE; ADLUPULONE; ALLO-AROMADENDRENE; ALLO-CYMENE; ALLOAROMADENDRENE-EPOXIDE; ALPHA-ALANINE; ALPHA-AMINO-ADIPIC-ACID; ALPHA-CADINENE; ALPHA-CADINOL; ALPHA-CARYOPHYLLENE; ALPHA-COPAENE; ALPHA-CORACALENE; ALPHA-CUBEBENE; ALPHA-EUDESMOL; ALPHA-GUAIENE; ALPHA-HUMULENE; ALPHA-MUUROLENE; ALPHA-PINENE; ALPHA-SELINENE; ALPHA-TERPINEOL; ALPHA-YLANGENE; ALUMINUM; AMMONIA(NH3); ARGININE; AROMADENDRINE; ASCORBIC-ACID; ASH; ASPARAGINE; ASPARAGINIC-ACID; ASTRAGALIN; BETA-ALANINE; BETA-CAROTENE; BETA-CARYOPHYLLENE; BETA-CUBEBENE; BETA-EUDESMOL; BETA-FARNESENE; BETA-PINENE; BETA-SELINENE; BETA-SELINENE-EPOXIDE-I; BETA-SITOSTEROL; BICYCLOGERMACRENE; BUTYLISOBUTYRATE; CADALENE; CAFFEIC-ACID; CALAMENENE; CALCIUM; CAMPESTEROL; CANNABIDIOL; CARBOHYDRATES; CARYOLAN-1-OL; CARYOPHYLLA-3(12)-6-DIEN-4-OL; CARYOPHYLLA-3(8)-13-DIEN-5-ALPHA-OL; CARYOPHYLLA-3(8)-13-DIEN-5-OL; CARYOPHYLLA-4(12)-8(13)-DIEN-5-BETA-OL; CARYOPHYLLENE-EPOXIDE; CARYOPHYLLENE-OXIDE; CATECHIN; CELLULOSE; CEROTIC-ACID; CHLOROGENIC-ACID; CHOLINE; CHROMIUM; CITRAL; COBALT; COHUMULONE; COLUPDOX; COLUPOX; COLUPULONE; CUBENOL; CYANIDIN; DECAN-1-AL; DELPHINIDIN; DELTA-CADINENE; DELTA-CADINOL; DELTA-GUAIENE; DELTA-SELINENE; DEMETHYL-XANTHOHUMOL; DEOXYCOHUMULONE; DEOXYHUMULONE; DIETHYL-AMINE; DIMETHYL-AMINE; DIPENTENE; EO; EPICATECHIN; EPICUBENOL; EPIGLOBULOL; ESTRADIOL; ESTRONE; ETHYL-AMINE; ETHYL-HEPTANOATE; ETHYL-METHYL-AMINE; EUGENOL; FARNESOL; FAT; FERULIC-ACID; FIBER; FORMALDEHYDE; FRIEDELIN; FRUCTOSE; GAMMA-AMINOBUTYRIC-ACID; GAMMA-CADINENE; GAMMA-CALOCORENE; GAMMA-ELEMENE; GAMMA-EUDESMOL; GAMMA-IONONE; GAMMA-LINOLENIC-ACID; GAMMA-MUUROLENE; GENTISIC-ACID; GERANIC-ACID-METHYL-ESTER; GERANIOL; GERANYL-ACETATE; GERANYL-ISOBUTYRATE; GERANYL-PROPIONATE; GERMACRATRIENE; GERMACRENE-B; GERMACRENE-D; GLOBULOL; GLUCOSE; HEDERAGENIN; HELUPONE; HEPTYLISOBUTYRATE; HEPTYLPROPIONATE; HEXYL-ISOBUTYRATE; HEXYLPROPIONATE; HISTIDINE; HULUPINIC-ACID; HULUPONE; HUMULENE; HUMULENE-DIEPOXIDE-A; HUMULENE-EPOXIDE-I; HUMULENE-EPOXIDE-II; HUMULENE-MONOEPOXIDE-I; HUMULENOL-II; HUMULINONE; HUMULOL; HUMULONE; IRON; ISOADHUMULONE; ISOCOHUMULONE; ISOHUMULONE; ISOLEUCINE; ISOMALTOSE; ISOPARAFFIN; ISOPENTENYL-NARANGENIN; ISOPENTYL-AMINE; ISOPREHUMULONE; ISOPRENE; ISOQUERCITRIN; ISOXANTHOHUMOL; JUNIPER-CAMPHOR; KAEMPFEROL; KAEMPFEROL-3-0-RUTINOSIDE; KAEMPFEROL-3-RHAMNODIGLUCOSIDE; KAEMPFEROL-3-RHAMNOSIDE; KILOCALORIES; LEDOL; LEUCINE; LEUCOCYANIDIN; LEUCODELPHINIDIN; LIGNIN; LIMONENE; LINALOL; LINALYL-ISONONYLATE; LINALYL-PROPIONATE; LUPARENOL; LUPAROL; LUPARONE; LUPULIN; LUPULONE; LYSINE; MAGNESIUM; MALTOSE; MANGANESE; MASLINIC-ACID; METACAMPHORENE; METHYL-2,5-DIMETHYLHEXENOATE; METHYL-2-METHYLNONANOATE; METHYL-4-METHYLHEX-2-ENOATE; METHYL-5-METHYLHEXANOATE; METHYL-6-METHYL-HEPTANOATE; METHYL-8-METHYLNONANOATE; METHYL-9-METHYLDECANOATE; METHYL-AMINE; METHYL-DECA-4,8-DIENOATE; METHYL-DECA-4-ENOATE; METHYL-DECANOATE; METHYL-DODECANOATE; METHYL-GERANATE; METHYL-GLUTAMIC-ACID; METHYL-HEPTANOATE; METHYL-HEXANOATE; METHYL-NONANOATE; METHYL-NONYL-KETONE; METHYL-OCTANOATE; METHYL-THIO-HUMULONE; METHYL-UNDECANOATE; METHYL-UNDECENOATE; METHYLDECENOATE; METHYLDODEC-8-EN-OATE; METHYLDODECADIENOATE; METHYLGLUTAMINE; METHYLNONENOATE; METHYLTHIOHEPTANOATE; METHYLTHIOHEXANOATE; METHYLTHIOISOHEPTANOATE; METHYLTRIDECENOATE; METHYLUNDECADIENOATE; MYRCENE; MYRCENOL; MYRICETIN; NEO-CHLOROGENIC-ACID; NEROL; NEROLIDOL; NERYLISOBUTYRATE; NERYLPROPIONATE; NIACIN; NONANYL; OCTYL-ACETATE; OCTYLISOBUTYRATE; OLEANOLIC-ACID; P-COUMARIC-ACID; P-CYMENE; PALUSTROL; PECTIN; PENTADECA-6,9-DIEN-2-ON; PENTENYLISOBUTYRATE; PENTOSAN; PENTYLISOBUTYRATE; PHENYLALANINE; PHENYLETHANOL; PHLOBAPHENE; PHOSPHORUS; PIPERIDINE; POSTHUMULONE; POTASSIUM; PREHUMULONE; PRELUPULONE; PROCYANIDINS; PRODELPHINIDIN-B-3; PROLINE; PROTEIN; PYRROLIDINE; QUERCETIN; QUERCETIN-3′-GLUCOSIDE; QUERCETIN-3-0-RUTINOSIDE; QUERCETIN-3-O-RHAMNOSIDE; QUERCETIN-3-RHAMNODIGLUCOSIDE; QUERCITRIN; RAFFINOSE; RESINS; RIBOFLAVIN; RUTIN; S-METHYLTHIO-2-METHYLBUTANOATE; S-METHYLTHIO-4-METHYLPENTANOATE; SELENIUM; SELIN-11-EN-OL; SELINA-3,7(11)-DIENE; SELINA-3,7-DIENE; SELINA-4(14),7(11)-DIENE; SERINE; SILICON; SODIUM; SPATHULENOL; SQUALENE; STACHYOSE; STIGMASTEROL; SUCROSE; T-CADINOL; TANNINS; TETRADEC-9-EN-2-ON; THIAMIN; THREONINE; TIN; TRICYCLO-DEHYDRO-HUMULONE; TRIMETHYLAMINE; TRYPTOPHAN; TYROSINE; UNDECAN-2-AL; URSOLIC-ACID; VALINE; VIRIDIFLORENE; VIRIDIFLOROL; WATER; XANTHOHUMOL; ZINC
Open Clinical Trials –
ClinicalTrials.gov ID: NCT01376869
Investigation of the Acute Cognitive, Mood and Autonomic Effects of Hops in Healthy Participants