Fagopyrum

Other Names

AjdaAlforfónBagonalBeech wheatBitter buckwheatBjoBlé de BarbarieBlé de sarrasinBlé noirBoekweitBokhveteBokkveiteBouquetteBoveteBrankBroBuchweizenBuckwheatBuckwheat herbCommon buckwheatDattan sobaDoronDroDuckwheatDyatEchter BuchweizenEr chiFafarFagginaFagopiroFagopyri herbaFagopyrum acutatumFagopyrum cerealeFagopyrum cymosumFagopyrum dibotrysFagopyrum dryandriiFagopyrum emarginatumFagopyrum esculentumFagopyrum fagopyrumFagopyrum homotropicumFagopyrum macropterumFagopyrum polygonumFagopyrum sagittatumFagopyrum tataricumFagopyrum vulgareFalscher BuchweizenGolden buckwheatGrano saracenoGrano sarracenoGrano turcoGrechikha posevnayaGrečicha kul'turnajaGrečicha posevnajaGrečihaGrečkaGreen buckwheatGrykaGryka siewnaGryka zwyczajnaGwinizh-duHajdinaHeidekornHeidenkornHeljdaHriškaIndian buckwheatIndian wheatIshisobaJapanese buckwheatJareKaspatKotiKotuKotulKu qiaoKu qiaommaiKutuKyoubakuMemilMe밀Mil des MauresMithe phapharNavadna ajdaOgalOogalPerennial buckwheatPhaaparPhaparPhapharPhapharaPhaphraPhegopyrum esculentumPogankaPohankaPohanka obecnáPolygonum cerealePolygonum fagopyrumQiao maiRenouée sarrasinSaracenSarasinSarrasinSarrasin de TartarieSilverhull buckwheatSobaSweet buckwheatTartary buckwheatTatar buckwheatTatarischer BuchweizenTatarka grykaTian qiao maiTite phapharTrigo mouroTrigo negroTrigo sarracenoVanligt bovete

Synopsis

Fagopyrum (Buckwheat): A Comprehensive Reference

1. Identity, Taxonomy, and Botanical Description

Genus and family. The genus Fagopyrum belongs to the flowering plant family Polygonaceae and includes important food plants such as F. esculentum (common buckwheat) and F. tataricum (Tartary buckwheat). It is a small genus, and most of its wild species are distributed in narrow areas in Southern Asia, mainly on the southeastern edge of the Qinghai-Tibetan Plateau.

Cultivated species. Two species are cultivated: common buckwheat (F. esculentum) and Tartary buckwheat (F. tataricum); a wild species, F. cymosum, is utilized as forage and a source of pharmaceutical drugs. The three best-known species are common buckwheat (Fagopyrum esculentum), Tartary buckwheat (Fagopyrum tataricum), and cymose buckwheat (Fagopyrum cymosum).

Etymological note. Buckwheat owes its botanical genus name to the Latin fagus (meaning "beech") and the Greek pyros (meaning "wheat"), reflecting the resemblance of its seeds to beechnuts; the species epithet esculentum is Latin for "edible."

Plant description. Fagopyrum esculentum is a warm-season, herbaceous annual flowering plant with erect, reddish stems and arrow-shaped leaves. It bears profuse shallow white flowers resembling those of knotweeds, which bloom quickly within 3 to 6 weeks after planting. The flowers are followed by dark brown, triangular seeds approximately the size of a soybean.

Pseudocereal status. Despite the common name and its grain-like use as a crop, buckwheat is not a grass and is therefore classified as a pseudocereal; it is not related to wheat or other monocots. Buckwheat is related to sorrel, knotweed, and rhubarb, and is known as a pseudocereal because its seeds' culinary use is the same as cereals, owing to their composition of complex carbohydrates.

Species differentiation. F. esculentum is an annual Asian herb with clusters of small pinkish or white flowers and edible triangular seeds, while F. tataricum is also an erect annual herb but with a smaller seed size. Detailed comparisons reveal that F. esculentum has advantages of sweet taste, large seed size, and easy dehulling of the seed coat. Tartary buckwheat (F. tataricum) contains more rutin and quercetin than common buckwheat (F. esculentum).

2. Common Forms and Preparations

The grain can be prepared by simple dehulling, milling into farina, or processed into whole-grain flour or white flour; it can also be fractionated into starch, germ, and hull for specialized uses. The hulled seeds (groats) are used in food preparations such as kasha. Buckwheat is also processed into products such as breakfast foods, flour, and soba noodles.

Buckwheat products include whole groats, cracked groats, flour, and tea, used in both sweet and savory dishes. In medicinal contexts, cut buckwheat herb is used for the preparation of a tea infusion, or powdered buckwheat herb is incorporated into tablets.

3. Historical and Traditional Use

3.1 Origin and Early Cultivation

Buckwheat was cultivated as early as 6,000 years ago, as evidenced by historical finds from Nepal, Siberia, Manchuria, and China. Nomads spread the grain across much of the world until it reached cool Europe in the 13th century. China was the earliest country in the world to cultivate buckwheat, beginning approximately 2,000 years ago by archaeological accounts, with genetic origins traced to Yunnan and Sichuan Provinces.

Buckwheat was brought from China to Japan via the Korean Peninsula and then to Europe via Siberia and southern Russia. Germany was the first country in Europe to grow buckwheat in 1396, followed by Belgium, France, Italy, and Britain in the 17th century; it was later brought to North America from the Netherlands.

3.2 Culinary Traditions

Buckwheat noodles have been eaten in Tibet and northern China for centuries, where the growing season is too short to raise wheat. A wooden press is used to press the dough into boiling water; old presses found in Tibet and Shanxi share the same basic design features, and the Japanese and Koreans are believed to have learned the process from them. Buckwheat noodles play a major role in the cuisines of Japan (soba) and Korea (naengmyeon, makguksu, and memil guksu). Soba noodles are the subject of deep cultural importance in Japan.

3.3 Traditional Medicinal Use

Tartary buckwheat (Fagopyrum tataricum) is a traditional herbal and functional food in China reported to be associated with decreased risk of type 2 diabetes mellitus. Fagopyrum tataricum is used for the treatment of type 2 diabetes mellitus in Taiwan. Both edible and versatile medicinal uses have a long tradition across the principal buckwheat species.

For approximately 20 years, flowering buckwheat herb has been used in therapeutic preparations in Europe to treat vascular diseases on account of its high rutin content; it was named the medicinal plant of the year in 1999. It is traditionally used alone or in combination with other preparations to improve the condition of tired legs, as recognized under the traditional use provisions of EU Directive 2001/83/EC.

4. Key Constituents and Active Compounds

4.1 Flavonoids

Flavonoids have been proven to be the major active compounds in Fagopyrum buckwheats, with the class and content varying in different parts of the plant. For example, six flavonoids — rutin, quercetin, orientin, vitexin, isovitexin, and isoorientin — were found in F. esculentum hulls, while only rutin and isovitexin were found in the seeds.

The dominant flavonoid across the genus is rutin (quercetin-3-rutinoside). Rutin is quercetin with a rutinose sugar attached, which is why it is also written as quercetin-3-rutinoside; that sugar changes how it behaves in the body compared to plain quercetin. Quantitative HPLC-based analysis of leaves of UK-grown F. esculentum showed a rutin content of 3,417 mg/100 g on a dry-weight basis.

Tartary buckwheat contains numerous functional components, including flavonoids, phenolic compounds, phytosterols, fagopyrins, D-chiro-inositol, and thiamin-binding proteins. The major flavonoids — rutin, quercetin, orientin, vitexin, and kaempferol — have been demonstrated to be responsible for its functional properties.

4.2 Fagopyritols and D-Chiro-Inositol

The seeds of buckwheat contain significant amounts of myo-inositol, D-chiro-inositol (DCI), and galactosyl derivatives of DCI commonly referred to as "fagopyritols." Analyses of the soluble carbohydrate composition demonstrated the presence of at least two galactosyl chiro-inositol isomers known as Fagopyritol A1 and Fagopyritol B1, at least two di-galactosyl chiro-inositol isomers known as Fagopyritol A2 and Fagopyritol B2, and small quantities of a tri-galactosyl chiro-inositol isomer known as Fagopyritol B3. Fagopyritols are found primarily in the embryo portion of buckwheat groats.

Fagopyritols are galactosyl derivatives of D-chiro-inositol, which are known to act as insulin mediators in the treatment of non-insulin-dependent diabetes mellitus. Of the six types of fagopyritols isolated from buckwheat seeds, fagopyritol A1 is the most prominent and is mainly present in the bran section; it is known to lower blood glucose levels in rats.

4.3 Fagopyrins

Fagopyrin is a phototoxic substance found in the flowers of buckwheat (Fagopyrum esculentum). Its chemical structure contains a naphthodianthrone skeleton similar to that of hypericin. After ingestion, fagopyrin can cause sensitivity to light, also known as fagopyrism, manifesting as an itchy skin rash. The substance was isolated from flowers of the red-flowering genotype of buckwheat in 1941, and its chemical structure was first described in 1979; within the edible parts of the plant, it is found exclusively in the brown fruit husk of buckwheat grains. Recent literature describes several variants of fagopyrin, referred to as fagopyrins A to F.

4.4 Additional Phenolic Compounds and Proteins

Polyphenols, flavonoids (mainly rutin, quercetin, emodin, and fagopyrin), proteins, vitamins (thiamine, riboflavin, and pyridoxine), and minerals (sodium, potassium, copper, zinc, and magnesium) are examples of bioactive compounds found in different vegetative parts and seeds of buckwheat. Four catechins and rutin were isolated from ethanol extracts of F. esculentum groats; chemical analysis also confirmed the plant contains cyclitols including fagopyritol A1, A2, A3, B1, B2, and B3.

The proteins in buckwheat seeds have been claimed to possess numerous health benefits, including hypocholesterolaemic, anti-inflammatory, and antioxidant effects, suppressing gallstones and tumors, and inhibiting the angiotensin I-converting enzyme.

5. Established Mechanisms of Action

5.1 Antioxidant Activity

At a concentration of 0.05 mg/mL, rutin exhibited 90.4% inhibition against the DPPH radical and showed effective inhibition of lipid peroxidation. When the extract of buckwheat herb was compared to pure rutin regarding antioxidant and radical-scavenging activity, the extract had significantly better antioxidant activity than pure rutin, suggesting that the minor phenolic compounds in the extract contribute importantly to this effect. The hulls, bran, and protein hydrolysates of F. esculentum exhibit excellent antioxidant effects, including free radical-scavenging ability and linoleic acid peroxidation-inhibiting ability.

5.2 Anti-Inflammatory Activity

Rutin, glycosides, and quercetin — the principal flavonoids in buckwheat — confer anti-inflammatory and antioxidant properties as well as favorable cardiovascular effects. Studies have demonstrated inhibition of cyclooxygenase 1 (COX-1) and COX-2 activity, with this activity decreasing proportionally with flavonoid content from sprouts to seeds. Rutin is a flavonoid with established antioxidant, anti-inflammatory, anti-diabetic, anti-cancer, and pro-lipid-metabolism effects, as documented across multiple peer-reviewed investigations.

5.3 Vascular and Capillary-Stabilizing Effects

The most consistent findings regarding rutin relate to blood vessels and microcirculation. One of the most studied areas is chronic venous insufficiency and related vein problems. Rutin and its semisynthetic derivatives (hydroxyethylrutosides) are understood to reduce capillary fragility and permeability through mechanisms including inhibition of inflammatory mediators and stabilization of endothelial cell junctions.

5.4 Antidiabetic Mechanisms

Phytochemicals from Tartary buckwheat, particularly flavonoids and D-chiro-inositol, alleviate increases in postprandial glucose and lower fasting glucose. The hypoglycemic effects of dietary fiber from buckwheat are mainly achieved through binding glucose and digestive enzymes, thereby inhibiting glucose release and absorption; soluble dietary fiber from Tartary buckwheat reached its highest inhibition activity plateau against α-glucosidase at a relatively low concentration of 0.8 mg/mL. D-chiro-inositol (DCI) is an active compound in Tartary buckwheat with insulin-like bioactivity.

5.5 Cardiomyocyte Effects (Preclinical)

Buckwheat rutin exhibited an inhibitory effect on angiotensin II-induced hypertrophy in cultured neonatal rat cardiomyocytes via calcium antagonism, blocking the calcineurin-dependent signal pathway. This is a preclinical, in vitro finding and has not yet been confirmed in human trials.

6. Scientific Evidence by Area of Use

6.1 Chronic Venous Insufficiency (CVI) and Vascular Health

The most robustly studied clinical application of buckwheat-derived preparations is in chronic venous insufficiency, principally through herbal tea preparations standardized for rutin content.

The efficacy of a buckwheat herb tea was assessed in a single-centre, randomized, double-blind, placebo-controlled clinical trial. Sixty-seven male and female patients aged 22–74 years with CVI were randomly divided into two groups after a 2-week run-in period and received either buckwheat herb tea (Fagopyrum esculentum) or a placebo tea for a period of 3 months. The main outcome measure was lower leg volume determined by ultrasound; subjective symptoms were assessed by a clinical symptom score, and femoral vein diameters were measured by B-scan sonography.

Although the mean partial leg volume did not change in the treatment group (from 2,041 to 2,073 mL), it increased in the placebo group by 110 mL (from 1,972 to 2,082 mL) according to intent-to-treat analysis. Subjective clinical symptoms were significantly reduced in both groups. Mean diameters of the femoral veins were reduced and capillary permeability improved, but neither change was statistically significant. No drug-related adverse effects were observed. The authors concluded that CVI is a very placebo-sensitive condition and that buckwheat herb tea treatment is safe and could have a favorable influence on patients with CVI in preventing further oedema development.

Semisynthetic derivatives of rutin (hydroxyethylrutosides / oxerutins) have been studied more extensively in CVI. Hydroxyethylrutosides (HR) are semisynthetic derivatives of rutin sold as standardized products for the treatment of CVI; commercially available products include Relvène (France), Venoruton (Switzerland), and Paroven (United Kingdom). However, systematic review found that the evidence for their efficacy is inconclusive. These derivatives are pharmacologically related to, but structurally distinct from, the naturally occurring rutin in buckwheat preparations and should not be equated with the unmodified botanical extract.

Evidence strength for CVI: Modest. There is one published randomized controlled trial using buckwheat herb tea itself (Ihme et al., 1996), with a positive trend on leg oedema prevention but limited statistical significance on vascular endpoints. The Cochrane review on phlebotonics for venous insufficiency has cited this trial in its reference list. Overall, this remains an area of traditional use with limited confirmatory clinical trial evidence for the whole herb/tea form.

6.2 Cardiometabolic Health: Cholesterol, Blood Glucose, and Cardiovascular Risk Markers

Two systematic reviews and meta-analyses have directly examined Fagopyrum and cardiometabolic outcomes in humans.

A 2018 meta-analysis aimed to summarize human and animal studies evaluating the impact of buckwheat consumption on cardiovascular disease risk markers; it identified 13 randomized controlled human studies, two cross-sectional human studies, and 21 animal studies. Using random-effects models, the weighted mean difference of post-intervention concentrations showed that blood glucose, total cholesterol, and triglycerides were significantly decreased following buckwheat intervention compared with controls (differences in blood glucose: −0.85 mmol/L [95% CI: −1.31, −0.39]; total cholesterol: −0.50 mmol/L [95% CI: −0.80, −0.20]; triglycerides: −0.25 mmol/L [95% CI: −0.49, −0.02]). All meta-analyses exhibited high unexplained heterogeneity, and there was inconsistency in HDL cholesterol outcomes in both human and animal studies.

A more recent 2022 systematic review and meta-analysis selected 16 human studies based on 831 subjects with mild metabolic disturbances, such as hypercholesterolemia, diabetes, and/or overweight. Weighted mean differences for subjects receiving buckwheat supplementation compared to controls were −0.14 mmol/L for total cholesterol, −0.03 mmol/L for LDL cholesterol, −0.14 kg for body weight, −0.04 mmol/L for HDL cholesterol, −0.02 mmol/L for triglycerides, and −0.18 mmol/L for glucose. Most of the studies (66.7%) had concerns of risk of bias, and studies investigating other CVD markers were scarce with inconsistent findings. The evidence on how buckwheat affects cardiometabolic health was judged to be limited.

The available literature indicates that buckwheat supplementation in mild dyslipidaemia and type 2 diabetes may provide some benefit in lowering total cholesterol and glucose, albeit non-significant in the 2022 meta-analysis. The authors highlight the need for more rigorous trials with better methodological quality.

Evidence strength for cardiometabolic health: Preliminary to moderate. Meta-analyses of multiple small human trials show trends toward benefit on blood glucose and total cholesterol, but heterogeneity is high, risk of bias is a concern in many trials, and most individual trial sizes are small. Animal data are more consistently positive but cannot be directly extrapolated to humans.

6.3 Glycaemic Control and Type 2 Diabetes

Tartary buckwheat is a traditional herbal and functional food in China associated with decreased risk of type 2 diabetes mellitus. It is rich in nutrients and phytochemicals; flavonoids and D-chiro-inositol alleviate postprandial glucose increases and lower fasting glucose.

A randomized controlled trial investigated the effect of Tartary buckwheat on renal function in type 2 diabetes mellitus patients. A significant protective effect of flavonoids from buckwheat on renal function was demonstrated in T2DM rats, but few studies had focused on the effect of Tartary buckwheat on renal function in humans at the time of that publication.

Fagopyrum tataricum is used for the treatment of type 2 diabetes mellitus in Taiwan; one study evaluated the antihyperglycaemic and anti-insulin resistance effects of 75% ethanol extracts of buckwheat in FL83B hepatocytes by high-glucose induction and in C57BL/6 mice by fructose-rich diet induction. This remains primarily preclinical evidence.

Tartary buckwheat contains several hypoglycemic and hypolipidemic compounds, including rutin, fagopyritols, D-chiro-inositol, and protein. Fagopyritols are galactosyl derivatives of D-chiro-inositol that act as insulin mediators; fagopyritol A1 is known to lower blood glucose levels in rats, suggesting that buckwheat fagopyritols have potential to emerge as dietary treatments for reducing symptoms of non-insulin-dependent diabetes mellitus.

Evidence strength for glycaemic control: Preliminary. Human evidence is limited to small trials, many of which have methodological limitations. Most mechanistic evidence on D-chiro-inositol and fagopyritols derives from animal and cell studies. A 2018 meta-analysis showed statistically significant blood glucose reductions, but the 2022 meta-analysis found the effect was non-significant, indicating the clinical picture remains uncertain.

6.4 Antioxidant and Anti-inflammatory Applications

The health benefits of buckwheat grains are mainly attributed to their bioactive phenolic compounds, especially rutin and quercetin, which have a positive impact on heart health, weight loss, and diabetes management. The antioxidant and anti-inflammatory activities of Fagopyrum preparations have been demonstrated extensively in cell and animal studies. Therapeutic benefits of the strong metal-chelating activity observed in buckwheat sprouts are noted in metal-catalyzed chronic diseases induced by oxidative stress, e.g., cardiovascular diseases; the chelating activity may be due to the higher content of rutin and quercetin, as they have more structural features for complexing metal ions.

Evidence strength for antioxidant/anti-inflammatory applications: Primarily in vitro and animal-based. Controlled human trials specifically targeting oxidative stress or inflammatory biomarkers as primary endpoints are lacking.

6.5 Renal Protection in Diabetes

Protein and flavonoids from Tartary buckwheat suppress hypercholesterolaemia and improve lipid profile; a significant protective effect of buckwheat flavonoids on renal function was demonstrated in T2DM rats, but human evidence at the time of that review was sparse. This area remains one primarily supported by preclinical research, with limited human confirmatory data.

7. Body Systems and Health Areas

Cardiovascular and vascular system: Rutin and related flavonoids support capillary integrity, reduce endothelial permeability, and have venotonic properties relevant to chronic venous insufficiency.
Metabolic and endocrine system: D-chiro-inositol, fagopyritols, and flavonoids are associated with improvements in insulin sensitivity and glycaemic control, particularly relevant to type 2 diabetes and metabolic syndrome.
Lipid metabolism: Buckwheat proteins and flavonoids are associated with hypocholesterolaemic effects in both animal models and some human studies.
Renal system: Preliminary evidence from animal studies suggests protective effects on kidneys in diabetic conditions, attributed to flavonoid content.
Antioxidant defense: High flavonoid and polyphenol content supports broad free radical-scavenging capacity across multiple tissue systems.
Skin (photosensitivity risk): The fagopyrin constituents of green plant parts interact with UV radiation, a consideration in preparations using flowers, sprouts, or green herbal extracts.

8. Dosage Forms and Reported Dosages

Tea preparations: the European traditional-use dosage described in herbal medicinal product guidance is one cup of buckwheat herb tea three times daily for several weeks; preparation involves pouring 150 mL of boiling water over 2 g of buckwheat herb, straining after 10 minutes, with an optional brief boiling of 2 to 3 minutes.

In the pivotal CVI clinical trial, 67 patients received buckwheat herb tea (Fagopyrum esculentum) or placebo tea for a period of 3 months. The study did not specify the exact daily rutin dose delivered.

The content of total dietary fiber in Tartary buckwheat bran was reported at 24.76% in the bran fraction, which is higher than that in flour. Studies on DCI-enriched Tartary buckwheat bran extract used animal models; steaming buckwheat bran in an autoclave significantly enriched the DCI level in the tartary buckwheat bran extract from 0.03% to 0.22%, and further to 22% after passage through activated carbon and ion exchange resins.

For cardiometabolic studies, eight studies investigating primarily grain components were included in the 2022 meta-analysis (n = 464 participants). Intervention forms and doses varied across studies, reflecting the heterogeneity noted by reviewers.

9. Safety Considerations and Interactions

9.1 Fagopyrism (Phototoxicity)

Buckwheat contains fluorescent phototoxic fagopyrins. A systematic review of fagopyrins and the phototoxicity of buckwheat found that reliable quantitative data on fagopyrin toxicity are not yet available. Generally, buckwheat seeds, flour, and teas are safe in normal amounts. Diets extensively composed of buckwheat sprouts, herbs, and particularly flowers, or fagopyrin-rich buckwheat extracts, may cause fagopyrism.

Fagopyrin is found in the flowers of buckwheat and has a naphthodianthrone skeleton similar to hypericin; after ingestion, it can cause sensitivity to light (fagopyrism), presenting as an itchy skin rash. Fagopyrism is a toxic reaction, not an allergy; it can occur after sunlight exposure and has principally been described in albino or partially pigmented animals such as swine, cattle, horses, sheep, or rabbits.

Standard commercial buckwheat foods like flour and groats contain negligible levels of fagopyrin due to milling and heat processing. A higher risk exists with large-scale consumption of raw sprouts or concentrated extracts from the green parts of the plant.

9.2 IgE-Mediated Allergy

Cultivated buckwheat species can cause IgE-mediated allergy, including severe allergic reactions and anaphylaxis. Exposure can occur when eating buckwheat food, when producing or handling buckwheat food (occupational exposure), or when sleeping on buckwheat husk pillows (household environmental exposure).

A number of allergenic proteins have been identified in common buckwheat (e.g., Fag e 1, Fag e 2, and Fag e 3) and in Tartary buckwheat (e.g., Fag t 1, Fag t 2, Fag t 3). Clinically relevant cross-reactivity has been described between buckwheat and peanut, latex, coconut, quinoa, and poppy seed. The prevalence of buckwheat allergy in the population is estimated at 0.1–0.4% in Japan, Korea, and buckwheat-consuming areas of China.

9.3 Pregnancy and Lactation

No safety studies are available on the use of buckwheat herb in therapeutic form during pregnancy and lactation.

9.4 Long-Term Safety Data

Most intervention trials of rutosides and related phlebotonics last from one to three months, occasionally extending to about ten months. As a result, the effects of years-long daily use of high-dose rutoside or hydroxyethylrutosides are not well characterized, and possible impacts on chronic disease risk, hormone-sensitive tissues, or kidney function over very long periods remain uncertain.

9.5 Cross-Reactivity and Drug Interactions

Rutin has relatively low oral bioavailability, and most of the more impressive data come from cell and animal studies rather than large human trials. In clinical practice, rutosides and their semisynthetic derivatives have been used for decades to help relieve symptoms of chronic venous insufficiency; beyond vein support, rutoside is valued for its antioxidant and capillary-stabilizing properties. The anticoagulant-related mild effects of rutin on blood clotting have been noted but warrant further research before firm clinical guidance can be established.

Gluten-free individuals should note that while buckwheat is naturally gluten-free, buckwheat products can be contaminated with gluten if processed in facilities that also handle wheat, which is a critical consideration for individuals with coeliac disease or severe gluten sensitivity.

References

Health Conditions

Health conditions that Fagopyrum may help support.

No conditions available.

Body Systems

Body systems that Fagopyrum may help support.

No body systems available.