Hops

Common Names

How It Works
Hops extracts have not been shown to treat or cure cancer.
Hops are traditionally used in beer brewing as flavoring agents. Studies done in laboratory and in animals have shown that hops extracts have antibacterial, anti-inflammatory, anti-diabetic and anticancer effects. In human studies, hops was found to benefit patients with type-2 diabetes, osteoarthritis, and insomnia. Hops extracts have also been used to reduce hot flashes in menopausal women.
Patients with hormone-sensitive cancers should consult their physicians before using products containing hops.
Purported Uses
- Arthritis
  When used in combination with rosemary leaf and oleanolic acid, hops extract reduced pain in patients with osteoarthritis.
- Sleeping aid
  When used in combination with valerian, hops extracts improved sleep in patients with mild insomnia. More data are needed.
- Menopausal symptoms
  Hops extract decreased hot flashes in menopausal women,
- Diabetes
  In a small study, hops extract lowered blood glucose and improved insulin sensitivity in patients with type-2 diabetes. Larger studies are required to confirm such effects.
Do Not Take If
- You are taking Cytochrome P450 substrates: Hops extracts were shown to inhibit CYP2C8, CYP1A2, CYP2C9 and CYP2C19 in vitro, and may affect the efficacy and safety of the substrate drugs when co-administered. Clinical relevance is not known.
- You are taking Paracetamol (Acetaminophen): Some hops species were shown to slow clearance of paracetamol, thereby increasing its analgesic effects, in murine models. Clinical relevance has yet to be determined.
Side Effects
- Several cases of respiratory disease have been associated with inhaling hop dust during harvest and processing.
Scientific Name
Humulus lupulus L.
Clinical Summary
Hops are the female inflorescences of the plant Humulus lupulus L. They are used primarily in beer brewing to add bitterness and flavor. Hops is also used as an herbal medicine for mood disturbance and insomnia ⁽¹⁾ and to treat menopausal symptoms. In vitro studies have shown that hops has antibacterial ⁽²⁸⁾, chemopreventive ⁽²⁾ ⁽³⁾ ⁽⁴⁾, antitumor ⁽⁵⁾, antiangiogenic ⁽⁶⁾, anti-inflammatory ⁽¹⁹⁾, phytoestrogenic ⁽²⁹⁾ and antidiabetic ⁽⁷⁾ properties. In murine models, hops reduced hyperlipidemia ⁽⁸⁾, obesity ⁽⁹⁾, protected against bone loss following estrogen depletion ⁽²¹⁾, and reduced development of acute alcohol-induced damage ⁽²²⁾.
In clinical studies, a hops-valerian combination product was reported to improve sleep quality ⁽¹⁰⁾ ⁽¹⁶⁾, and insulin sensitivity in patients with type-2 diabetes ⁽⁷⁾. Hops extracts were also shown to alleviate mild depression, anxiety and stress symptoms in healthy adults ⁽²³⁾; and to decrease body fat in healthy overweight subjects ⁽²⁴⁾. Data from an observational study suggest benefits of a combination of hops, rosemary extract and oleanolic acid in reducing arthritic pain ⁽¹¹⁾. However, it is not clear whether hops alone would exert similar effects.
In addition, hops extracts were shown to alleviate menopausal symptoms ⁽¹³⁾ ⁽¹⁷⁾ ⁽²⁵⁾, and may improve bone health ⁽¹⁸⁾ in postmenopausal women. Some studies also indicate that derivates of hops have phytoestrogenic effects ⁽⁷⁾ ⁽¹²⁾. Patients with hormone-sensitive cancers should consult their physicians before using products containing hops.
Food Sources
Female inflorescences of Humulus lupulus L.
Purported Uses
- Arthritis
- Fibromyalgia
- Insomnia
- Menopausal symptoms
- Diabetes
Mechanism of Action
Isomerized hops extracts (IHEs) increase plasma HDL levels and decrease atherosclerosis index (AI) in mice on high fat, high cholesterol diet via PPAR-alpha activation ⁽¹⁴⁾. These extracts also reduced plasma triglyceride levels and induced hepatomegaly ⁽⁸⁾. A product containing hops extract reduces levels of C-reactive protein in patients with inflammatory diseases ⁽¹²⁾.
Prenyl flavonoids from hops, xanthohumol, isoxanthohumol, and 8-prenylnaringen (8-PN) inhibit aromatase activity and breast cancer cell proliferation, increase apoptosis ⁽⁵⁾, and inhibit prostate cancer cell proliferation ⁽³⁾. 8-PN has also been reported to be among the potent estrogen receptor alpha (ERα) phytoestrogens, which is likely responsible for relief of menopausal symptoms ⁽²⁹⁾. In addition, xanthohumol exhibits antiangiogenic effect by inhibiting the NF-kB and Akt pathway ⁽⁶⁾; isoadhumulone, isocohumulone and isohumulone derived from hops were shown to selectively inhibit aldo-keto-reductase 1B10 (AKR1B10), which is upregulated in various cancers promoting carcinogenesis ⁽³⁰⁾.
The isoxanthohumols are converted in the distal human gut into 8-PN via the action of intestinal microflora ⁽¹²⁾. This process also occurs in the liver and is regulated by the cytochrome P450 enzymes ⁽¹⁵⁾.
Adverse Reactions
- Several cases of respiratory disease have been associated with inhaling hop dust during harvest and processing ⁽²⁶⁾.
Herb-Drug Interactions
- Cytochrome P450 substrates: Hops extracts were shown to inhibit CYP2C8, CYP1A2, CYP2C9 and CYP2C19 in vitro, and may affect the efficacy and safety of the substrate drugs when co-administered. Clinical relevance is not known ⁽²⁷⁾.
- Paracetamol (Acetaminophen): Some hops species were shown to slow clearance of paracetamol, thereby increasing its analgesic effects, in murine models. Clinical relevance has yet to be determined ⁽²⁰⁾.
Herb Lab Interactions
- Isomerized hops extracts (IHEs) may increase plasma HDL levels ⁽¹⁴⁾.
- Hops extract in combination with rosemary extract and oleanolic acid may reduce C-reactive protein in patients presenting with elevated levels ⁽¹¹⁾.
References
1. Piersen CE. Phytoestrogens in botanical dietary supplements: implications for cancer. Integr Cancer Ther. Jun 2003;2(2):120-138.
2. Dietz BM, Kang YH, Liu G, et al. Xanthohumol isolated from Humulus lupulus Inhibits menadione-induced DNA damage through induction of quinone reductase. Chem Res Toxicol. Aug 2005;18(8):1296-1305.
3. Delmulle L, Bellahcene A, Dhooge W, et al. Anti-proliferative properties of prenylated flavonoids from hops (Humulus lupulus L.) in human prostate cancer cell lines. Phytomedicine. Nov 2006;13(9-10):732-734.
4. Nozawa H, Nakao W, Zhao F, Kondo K. Dietary supplement of isohumulones inhibits the formation of aberrant crypt foci with a concomitant decrease in prostaglandin E2 level in rat colon. Mol Nutr Food Res. Aug 2005;49(8):772-778.
5. Monteiro R, Faria A, Azevedo I, Calhau C. Modulation of breast cancer cell survival by aromatase inhibiting hop (Humulus lupulus L.) flavonoids. J Steroid Biochem Mol Biol. Jun-Jul 2007;105(1-5):124-130.
6. Albini A, Dell’Eva R, Vene R, et al. Mechanisms of the antiangiogenic activity by the hop flavonoid xanthohumol: NF-kappaB and Akt as targets. FASEB J. Mar 2006;20(3):527-529.
7. Yajima H, Ikeshima E, Shiraki M, et al. Isohumulones, bitter acids derived from hops, activate both peroxisome proliferator-activated receptor alpha and gamma and reduce insulin resistance. J Biol Chem. Aug 6 2004;279(32):33456-33462.
8. Shimura M, Hasumi A, Minato T, et al. Isohumulones modulate blood lipid status through the activation of PPAR alpha. Biochim Biophys Acta. Sep 5 2005;1736(1):51-60.
9. Yajima H, Noguchi T, Ikeshima E, et al. Prevention of diet-induced obesity by dietary isomerized hop extract containing isohumulones, in rodents. Int J Obes (Lond). Aug 2005;29(8):991-997.
10. Morin CM, Koetter U, Bastien C, Ware JC, Wooten V. Valerian-hops combination and diphenhydramine for treating insomnia: a randomized placebo-controlled clinical trial.Sleep. Nov 1 2005;28(11):1465-1471.
11. Lukaczer D, Darland G, Tripp M, et al. A pilot trial evaluating Meta050, a proprietary combination of reduced iso-alpha acids, rosemary extract and oleanolic acid in patients with arthritis and fibromyalgia. Phytother Res. Oct 2005;19(10):864-869.
12. Possemiers S, Bolca S, Grootaert C, et al. The prenylflavonoid isoxanthohumol from hops (Humulus lupulus L.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human intestine. J Nutr. Jul 2006;136(7):1862-1867.
13. Heyerick A, Vervarcke S, Depypere H, Bracke M, De Keukeleire D. A first prospective, randomized, double-blind, placebo-controlled study on the use of a standardized hop extract to alleviate menopausal discomforts. Maturitas. May 20 2006;54(2):164-175.
14. Miura Y, Hosono M, Oyamada C, Odai H, Oikawa S, Kondo K. Dietary isohumulones, the bitter components of beer, raise plasma HDL-cholesterol levels and reduce liver cholesterol and triacylglycerol contents similar to PPARalpha activations in C57BL/6 mice. Br J Nutr. Apr 2005;93(4):559-567.
15. Guo J, Nikolic D, Chadwick LR, Pauli GF, van Breemen RB. Identification of human hepatic cytochrome P450 enzymes involved in the metabolism of 8-prenylnaringenin and isoxanthohumol from hops (Humulus lupulus L.). Drug Metab Dispos. Jul 2006;34(7):1152-1159.
16. Dimpfel W, Suter A. Sleep improving effects of a single dose administration of a valerian/hops fluid extract – a double blind, randomized, placebo-controlled sleep-EEG study in a parallel design using electrohypnograms. Eur J Med Res. 2008 May 26;13(5):200-4.
17. Erkkola R, Vervarcke S, Vansteelandt S, et al. A randomized, double-blind, placebo-controlled, cross-over pilot study on the use of a standardized hop extract to alleviate menopausal discomforts. Phytomedicine. 2010 May;17(6):389-96.
18. Holick MF, Lamb JJ, Lerman RH,et al. Hop rho iso-alpha acids, berberine, vitamin D3 and vitamin K1 favorably impact biomarkers of bone turnover in postmenopausal women in a 14-week trial. J Bone Miner Metab. 2010 May;28(3):342-50.
19. Akazawa H, Kohno H, Tokuda H, et al. Anti-inflammatory and anti-tumor-promoting effects of 5-deprenyllupulonol C and other compounds from Hop (Humulus lupulus L.). Chem Biodivers. 2012 Jun;9(6):1045-54.
20. Jakovljevic V, Popovic M, Raskovic A, et al. Effect of aroma and magnum hops extracts and paracetamol on antioxidant liver parameters in mice. Eur J Drug Metab Pharmacokinet. 2009 Jan-Mar;34(1):37-41.
21. Keiler AM, Helle J, Bader MI, et al. A standardized Humulus lupulus (L.) ethanol extract partially prevents ovariectomy-induced bone loss in the rat without induction of adverse effects in the uterus. Phytomedicine. 2017 Oct 15;34:50-58.
22. Hege M, Jung F, Sellmann C, Jin C, Ziegenhardt D, Hellerbrand C, Bergheim I. An iso-α-acid-rich extract from hops (Humulus lupulus) attenuates acute alcohol-induced liver steatosis in mice. Nutrition. 2018 Jan;45:68-75.
23. Kyrou I, Christou A, Panagiotakos D, et al. Effects of a hops (Humulus lupulus L.) dry extract supplement on self-reported depression, anxiety and stress levels in apparently healthy young adults: a randomized, placebo-controlled, double-blind, crossover pilot study. Hormones (Athens). 2017 Apr;16(2):171-180.
24. Morimoto-Kobayashi Y, Ohara K, Ashigai H, et al. Matured hop extract reduces body fat in healthy overweight humans: a randomized, double-blind, placebo-controlled parallel group study. Nutr J. 2016 Mar 9;15:25.
25. Aghamiri V, Mirghafourvand M, Mohammad-Alizadeh-Charandabi S, Nazemiyeh H. The effect of Hop (Humulus lupulus L.) on early menopausal symptoms and hot flashes: A randomized placebo-controlled trial. Complement Ther Clin Pract. 2016 May;23:130-5.
26. Reeb-Whitaker CK, Bonauto DK. Respiratory disease associated with occupational inhalation to hop (Humulus lupulus) during harvest and processing. Ann Allergy Asthma Immunol. 2014 Nov;113(5):534-8.
27. Yuan Y, Qiu X, Nikolić D, et al. Inhibition of human cytochrome P450 enzymes by hops (Humulus lupulus) and hop prenylphenols. Eur J Pharm Sci. 2014 Mar 12;53:55-61.
28. Bocquet L, Sahpaz S, Bonneau N, Beaufay C, et al. Phenolic Compounds from Humulus lupulus as Natural Antimicrobial Products: New Weapons in the Fight against Methicillin Resistant Staphylococcus aureus, Leishmania mexicana and Trypanosoma brucei Strains. Molecules. 2019 Mar 14;24(6). pii: E1024.
29. Chadwick LR, Nikolic D, Burdette JE, et al. Estrogens and congeners from spent hops (Humulus lupulus). J Nat Prod. 2004 Dec;67(12):2024-32.
30. Seliger JM, Cicek SS, Witt LT, Martin HJ, Maser E, Hintzpeter J. Selective Inhibition of Human AKR1B10 by n-Humulone, Adhumulone and Cohumulone Isolated from Humulus lupulus Extract. Molecules. 2018 Nov 21;23(11). pii: E3041.