IngredientsSumac (Rhus coriaria L.) is a member of the Anacardiaceae family, a medicinal and aromatic plant historically known for its use both as a culinary spice and in traditional medicine. Rhus coriaria L., commonly known as sumac, is a shrub of the Anacardiaceae family present in various subtropical and temperate regions of the world. It is native to the Mediterranean Basin and is a useful plant for food and medical purposes. Sumac exhibits a wide distribution across Africa, South Eastern Anatolia, the Mediterranean region, and Western Asia.
The word "sumac" is derived from the Arabic term summaq (سماق), which refers to the dark red color of the spice. The term has been adopted into various languages, including Persian as sumaq and Turkish as sumak. The etymology of sumac reflects its widespread use and cultural significance across the Middle East and beyond.
Sumac (Rhus coriaria) is a shrub native to the Mediterranean region, known for its deep red berries that are dried and ground into a coarse, crimson powder. In botanical research, multiple parts of the plant have been studied, including the fruits, leaves, and bark. The fruits are the primary part used as a spice and dietary supplement.
While Rhus coriaria is not native to North America, other Rhus species, such as Rhus typhina (staghorn sumac) and Rhus glabra (smooth sumac), are prevalent in that region. Native American communities have long utilized these species for various purposes, including culinary and medicinal uses. It is important to distinguish between the culinary sumac commonly used in Middle Eastern cuisine (Rhus coriaria) and the native sumac species of North America, since while the North American species can be used similarly, their flavor profiles and chemical compositions may differ slightly. Poison sumac, known as Toxicodendron vernix, also belongs to the Anacardiaceae family but is a distinct and toxic species unrelated to culinary sumac.
Sumac spice is a tangy red-purple powder produced by drying and grinding the hairy clusters of sumac fruit. It is often used in several regions to add a lemony and astringent taste to many dishes. In research settings, preparations have included dried fruit powder, aqueous extracts, alcoholic (methanol, ethanol) extracts, and encapsulated fruit powder. In folk use, the powdered spice product from the dried fruit was spread on boiled eggs and consumed for diarrhea treatment. A fruit decoction has been traditionally administered for the treatment of hepatic diseases, urinary system disorders, and diarrhea.
Rhus coriaria L. (Anacardiaceae), commonly known as sumac, has been used since ancient times for many different applications, and nowadays is used mostly as a spice obtained from its ground fruits and employed for flavoring and garnishing food, predominantly in the Mediterranean and Middle Eastern regions. Traditionally, sumac has been used in popular medicine for the treatment of many ailments including hemorrhoids, wound healing, diarrhea, ulcers, and eye inflammation.
Sumac played a significant role in ancient Mediterranean cuisine and culture. Its use extended beyond the kitchen, with sumac being used in traditional medicine, rituals, and as a dye. In ancient Mediterranean cuisine, sumac was a staple spice used to add flavor to a variety of dishes; the ancient Greeks and Romans used sumac to season meat, fish, and vegetables.
In Iran, Rhus coriaria is traditionally used as a table spice, especially along with rich dishes, and is highly recommended for adjustment of the blood lipids in diabetic patients. Sumac features in classical Persian medicine texts spanning many centuries. The plant (Rhus coriaria L.) is referenced in major Iranian traditional textbooks including the Canon of Medicine (Avicenna, 980–1037 AD), Al-Hawi (Razes, 865–925 AD), Tuhfat ul-Momineen (Mo'men Tonekaboni, 17th century), Makhzan-ul-Adwiah (Aghili, 18th century), Ikhtiarat Badi'i (Ansari, 1329–1404 AD), and Al-jāmi li-mufradāt al-adwiya wa al-aghdhiya (Ibn al-Baitar, 1197 AD). Persian medicine, as one of the oldest traditional and complementary medicine traditions in the world, includes contributions from great scientists such as Ibn Sina and Razi and is currently gaining increasing popularity after rigorous modern research.
Dakota and Ojibwe peoples have used sumac for generations to boost the immune system and soothe sore throats and colds. The bark and leaves have been used to treat infections, stomach problems, and skin conditions like poison ivy. Staghorn sumac has been used by Indigenous peoples, including the Dakota and Ojibwe, for centuries, and its berries are an important source of Vitamin C and are often used in teas to prevent illness. The Comanche chewed the bark and swallowed the resulting juice for treating colds. In California, the Indians of Round Valley applied the dried and powdered berries to smallpox sores.
Sumac is employed as a natural preservative in the food sector due to its rich content of antioxidant compounds, including hydrolysable tannins, phenolic acids, anthocyanins, and flavonoids. Research has evaluated its potential as a food preservative for nutraceutical exploitation. In recent years, utilization of Rhus coriaria L. (sumac) has been upgrading not only in culinary use and human nutrition, but also in the pharmaceutical industry, food industry, and veterinary practices, driven by accumulating evidence that supports the ethnobotanical use of this plant.
As of recent reviews, over 200 phytochemicals have been isolated from Rhus coriaria, including organic acids, phenolic acids, phenolic compounds conjugated with malic acid derivatives, flavonoids, isoflavonoids, hydrolysable tannins, anthocyanins, terpenoids, and other compounds such as butein, iridoid, and coumarin derivatives.
The overall composition of the dried sumac fruit is mainly composed of moisture (6–11.8%), essential oil content (1.0%), protein (2.3–2.6%), fiber (14.6–22.15%), ash (1.5–2.66%), water-soluble extract (63.8%), and fatty oil (17.4%).
Hydrolysable tannins compose the highest percentage in the sumac fruits, followed by flavonoids. This emphasizes the antioxidant potential of the fruit. Following hydrolysable tannins, comprising almost 20% of the fruit's mass, are other still unidentified compounds. Six gallotannins have been identified: penta-, hexa-, hepta-, octa-, nona-, and decagalloyl-glucoside. Tannins are the compounds responsible for the astringent taste of sumac.
The fruits and leaves of Rhus coriaria contain various phenolic acids such as gallic acid, ellagic acid, caffeic acid, and chlorogenic acid; flavonoids including quercetin, rutin, kaempferol, luteolin, and apigenin; as well as anthocyanins such as cyanidin, delphinidin, and peonidin. Other significant phytochemical groups include gallotannins, ellagitannins, volatile compounds, organic acids, sugars, polysaccharides, sterols, and vitamins.
Hydroxyphenyl pyranoanthocyanins and other anthocyanins are responsible for the highly desired red pigments, accounting for the strong pigmentation capacity and colorant ability of sumac. Anthocyanins are abundant in sumac fruits.
Among the volatile constituents identified from sumac, the main components were α-pinene (44%), limonene (20%), and β-pinene (11.4%).
Most of the antioxidant potential and therapeutic roles of sumac are increasingly attributed to its constituent tannins, flavonoids, and phenolic acids. Sumac is a spice with remarkable antioxidant activity thanks to the high presence of phenolic compounds. Sumac is considered a valuable plant that contains nutritious elements such as proteins, unsaturated fatty acids, dietary fibers, minerals, vitamins, and many polyphenols, and its phenolic content contributes to activate its medical and therapeutic role.
Polyphenol-rich acetone extracts and ethanol extracts derived from fruit samples of sumac show strong antioxidant capacity. Rhus coriaria has significant antioxidative potential due to its richness in phenolic compounds, especially gallic acid and its derivatives. Sumac drupes are rich in various classes of phytochemicals including organic acids, flavonoids, tannins, and others, which are responsible for their powerful antioxidant capacity.
In cell-based studies involving Helicobacter pylori infection, sumac extracts inhibited IL-8 release (IC₅₀s <70 μg/mL) and exhibited direct antibacterial activity at comparable concentrations (MIC = 100 μg/mL). The phenolic content and bioactivity were associated with nuclear factor kappa B (NF-κB) impairment, considered the main putative anti-inflammatory mechanism.
Data from pharmacological studies emphasize the significant value of sumac fruit in inducing beneficial vasorelaxant actions through adenylyl cyclase (AC) and guanylyl cyclase (GC) signaling pathways, including the potential of cross-talk between the two systems. These findings offer a mechanistic explanation for the use of sumac in folk medicine for amelioration of cardiovascular diseases.
At non-cytotoxic doses, sumac significantly modulates the growth of MCF-7 (breast), PC-3 (prostate), and SKOV3 (ovarian) cancer cells with a higher inhibitory effect and selectivity to carbonic anhydrase (CA) isoforms (hCA I, II, IX, and XII). The data showed that sumac at doses of 50 and 100 μM significantly inhibited the growth, proliferation, and viability of cancer cells by activating the apoptotic process via caspase-3 overexpression and the regulation of Bcl-2 anti-apoptotic protein.
In vitro hypoglycemic activity of the methanolic extract of Rhus coriaria fruits is partly attributable to inhibition of α-amylase (87% inhibition at 50 μg/mL).
Many clinical trials have investigated the effects of sumac (Rhus coriaria) supplementation on cardiovascular disease risk factors (CVDRFs); however, these studies have yielded contradictory findings.
A study designed to investigate the clinical effects of sumac fruits on dyslipidemia in 12–18 year-old adolescents was conducted as a randomized triple-blinded clinical trial on 72 obese adolescents with dyslipidemia. Eligible adolescents were randomly assigned to case and control groups; the case group received capsules containing 500 mg of powdered sumac fruits three times a day for one month. In patients with dyslipidemia, a triple-blind randomized placebo-controlled crossover trial reported improvement in endothelial vasodilator function, including flow-mediated dilation (FMD), after consumption of a daily dose of 500 mg of Rhus coriaria fruits for 4 weeks. Furthermore, significant reduction in systolic and diastolic blood pressure, total serum cholesterol, LDL-C, non-HDL-C, and BMI was observed in the Rhus coriaria-treated group compared to placebo.
A meta-analysis study revealed that Rhus coriaria exerts a positive effect on different indices of the lipid profile, including increasing Apo A-I and HDL, and decreasing Apo B, Apo B/Apo A-I ratio, total cholesterol, LDL, and triglycerides.
Evidence strength: Many clinical trials have investigated the effects of sumac supplementation on CVD risk factors; however, these studies have yielded contradictory findings. The overall literature on lipid lowering is promising but heterogeneous, and effect sizes vary across populations and preparations.
In a double-blind randomized controlled clinical trial on 41 type 2 diabetic volunteers randomly assigned into 3 g/day sumac powder (n=22) or placebo (n=19) groups over 3 months, there were significant decreases in serum glucose and HbA1c and also apoB levels at the end of the study compared with initial values (P<0.0001, P=0.002 and P<0.0001, respectively).
A separate double-blind randomized placebo-controlled trial on 41 type 2 diabetic volunteers was conducted, with participants randomly assigned into 3 g per day sumac powder (n=22) or placebo (n=19) groups for 3 months, to determine the effect of sumac powder on insulin resistance (IR), malondialdehyde (MDA), high-sensitivity C-reactive protein (hs-CRP), and paraoxonase 1 (PON1) activity.
However, at the meta-analytic level, results are not uniformly positive. A random-effects meta-analysis of 6 clinical trials (278 participants total) suggested no statistically significant effects on fasting blood glucose [−7.08 mg/dL, 95% CI: −14.85 to 0.70, P=0.07], HbA1c [−0.48%, 95% CI: −1.01 to −0.04, P=0.07], HOMA-IR [−0.97, 95% CI: −1.96 to 0.02, P=0.05], or insulin [−2.94 Hedges' g, 95% CI: −6.67 to 0.80, P=0.12] following supplementation with sumac powder. This meta-analysis thus found no significant effects on any glycemic indices. The authors noted that more high-quality RCTs with longer duration are needed to further clarify the effects of sumac on blood glucose control, especially among patients with diabetes.
Evidence strength: Individual RCTs have shown reductions in glucose and HbA1c, but a pooled meta-analysis found no statistically significant benefit across glycemic indices. Evidence is mixed and preliminary; heterogeneity across studies is high.
Sumac is a medicinal plant with potential anti-inflammatory properties; however, the effects of sumac supplementation on inflammatory biomarkers, particularly hs-CRP, remain controversial. Clinical trials have shown that sumac can reduce oxidative stress markers and improve antioxidant capacity, although its effects on inflammation are less consistent, with some studies reporting no significant changes in inflammatory markers like TNF-α and IL-6. However, sumac has demonstrated potential in reducing inflammation in specific conditions, such as gastritis and gouty arthritis, by modulating inflammatory pathways.
Subgroup analyses from a recent systematic review revealed that sumac supplementation led to a significant reduction in hs-CRP concentrations in trials that included both genders, or in studies conducted on patients with non-alcoholic fatty liver disease, individuals who were overweight, or those aged ≥45 years. Overall, sumac supplementation may significantly reduce hs-CRP concentrations in adults, but further high-quality, large-scale trials are required to confirm these findings and determine optimal dosage and duration.
An in vitro study offered what was described as the first demonstration of the potential role of sumac as a nutraceutical useful in H. pylori-related gastritis.
Evidence strength: Preliminary to moderate; anti-inflammatory effects are plausible via NF-κB inhibition but clinical evidence is inconsistent and context-dependent. Most definitive data remain from in vitro and animal studies.
A randomized, double-blind, placebo-controlled clinical trial examined sumac as a novel adjunctive treatment in hypertension. A meta-analysis of 15 RCTs found that sumac consumption significantly reduced diastolic blood pressure (WMD = −2.88 mmHg; 95% CI, −4.22 to −1.54; P=0.001), fasting blood glucose (WMD = −5.15 mg/dL; 95% CI, −8.73 to −1.57; P=0.005), and insulin levels. The plant may therefore serve as a resource for nutraceuticals and therapeutic agents for ameliorating cardiovascular diseases, including atherosclerosis, aortic aneurysms, and hypertension.
Evidence strength: Early-stage but promising in specific populations; effect on diastolic blood pressure was statistically significant in meta-analysis, though individual studies are small and short-term.
Antimicrobial activities of Iranian sumac against food-borne bacteria have been studied. Spices have been used safely since ancient times as food flavoring agents and also as herbal medicines and are now mainly considered "generally regarded as safe" (GRAS). Demonstrated activities of Rhus coriaria include antioxidant, antimicrobial, antidiabetic, cardioprotective and antidyslipidemic, antinociceptive, neuroprotective, dental protection, and anticancer effects. In vitro studies have shown that sumac extracts inhibited IL-8 release (IC₅₀s <70 μg/mL) during Helicobacter pylori infection and exhibited a direct antibacterial activity at comparable concentrations (MIC = 100 μg/mL).
Evidence strength: Primarily in vitro and animal data. There are no published large-scale human clinical trials specifically examining sumac's role in treating clinical infections.
A recent study investigated the neuroprotective effect of extract obtained from sumac fruit samples through an in vitro cellular model of neuroinflammation. The authors observed that the sumac extract exhibited a potent anti-inflammatory potential on cell lines through inhibition of reactive oxygen species (ROS) and nitric oxide. In an animal model, treatment with sumac extracts exerted neuroprotective and anti-inflammatory effects in a mouse model of ischemic optic neuropathy. These findings suggest the potential of sumac in ameliorating neuroinflammation and neurodegenerative diseases.
Evidence strength: Exclusively preclinical (in vitro and animal). No human clinical trials on neurological outcomes have been identified in the peer-reviewed literature.
Scientific reports have provided evidence of the inhibitory role of sumac on tumor growth and survival. Research revealed anti-breast cancer activity of sumac extracts using various breast cancer cell lines; the authors reported that sumac extracts promoted senescence and autophagic cell death, suppressed cell migration, invasion, and metastasis.
Evidence strength: All evidence is from in vitro cell-line studies. No clinical trials in cancer patients have been reported. These findings should not be extrapolated to therapeutic use in humans.
The hepatoprotective effects of sumac fruit have been evaluated in a rat model of paracetamol-induced liver injury. The experimental design relied on pretreatment of rats with intraperitoneal sumac extract followed by a toxic dose of paracetamol. Rats pre-treated with sumac displayed attenuated signs of toxicity; sumac-pretreated animals showed a minimal increase in liver enzyme levels. In parallel, serum albumin and total protein levels were close to normal, and pretreated sumac animals had preserved hepatocyte morphology, whereas unprotected animals had necrotic deformations. Importantly, these effects were dose-dependent and comparable to the silymarin-treated positive control group.
Evidence strength: Animal data only. No human trials on hepatoprotection have been identified.
A double-blind randomized clinical trial examined the effect of sumac powder on clinical symptoms, hyperandrogenism, inflammation, blood glucose, and lipid profiles in women with polycystic ovary syndrome.
Evidence strength: A limited number of RCTs; this is an emerging area and replication in larger, independently conducted trials is needed before conclusions can be drawn.
Rhus coriaria L. is a commonly used spice rich in various classes of phytochemicals including flavonoids, tannins, polyphenolic compounds, and organic acids, and may be beneficial for cardiovascular disease risk factors. A comprehensive systematic review and meta-analysis assessed the impact of sumac supplementation on cardiovascular disease risk factors, including anthropometric measures, glycemic profile, inflammatory markers, and lipid profile, and explored the dose-response relationship and optimal duration. Relevant randomized clinical trials were identified through electronic database searches up to March 2025. The Cochrane risk-of-bias tool was employed to evaluate study quality. The overall conclusion was that sumac supplementation enhances glycemic control and lipid metabolism, indicating potential cardiometabolic benefits in reducing cardiovascular disease risk factors. However, existing evidence from multiple randomized clinical trials on the effects of sumac is heterogeneous.
The following dosages are reported directly from published clinical studies and are described for reference purposes only.
In recent decades, the utilization of sumac spice is expanding based on increasing empirical evidence that supports its ethnopharmacological use and advanced knowledge of the content of nutritionally and medicinally important metabolites such as proteins, unsaturated fatty acids, fiber, and minerals, essential oils, phenolic acids, tannins, anthocyanins, and organic acids. Such evidence has been widely reported from in vitro and in vivo studies, and many have reached the stage of clinical trials in humans.
From the search of available literature, sumac has maintained a good track record for safety, with little or no reported adverse effects. Toxicity studies show that sumac is very safe to consume by humans and has little toxicity.
Sumac has maintained a good track record for safety, with little or no reported adverse effects. However, the fact that sumac belongs to the cashew family Anacardiaceae means people with allergies to those foods may want to take caution in the use of sumac to avoid any potential allergic reactions. Poison sumac, also known as Toxicodendron vernix, also belongs to the Anacardiaceae.
Proper identification of Rhus coriaria is important to avoid confusion with toxic species, especially if foraging for the plant. If there is any uncertainty regarding the type of sumac, it is best to avoid consumption to prevent potential adverse effects.
When using Rhus coriaria medicinally, it is important to follow dosage instructions carefully because this plant contains tannins and gallic acid, which can cause gastrointestinal irritation and allergic reactions if not used in moderation.
Given the clinical trial data showing reductions in both blood pressure and glycemic indices in specific populations, combination strategies involving sumac may require particular attention to potential adverse interactions in patients with comorbid conditions such as metabolic syndrome, type 2 diabetes, or dyslipidemia.
Many clinical trials have indicated the potent antidiabetic property of sumac, but the results on glycemic indices were inconclusive; patients on antidiabetic medications who also supplement with sumac would be advised by study authors that monitoring is warranted. Similarly, studies showing blood pressure-lowering effects indicate that use alongside antihypertensive medications could require monitoring. Future research should explore genetic polymorphisms and other biomarkers that predict individual responsiveness to sumac supplementation, as tailoring treatment based on such factors could lead to more nuanced, patient-specific recommendations.
The clinical trial literature consistently excludes pregnant and lactating women from sumac supplementation trials. In published RCTs, pregnancy and lactation were explicitly listed as exclusion criteria. There is insufficient published clinical evidence to characterize safety in these populations.
Old or spoiled sumac may contain harmful compounds that can cause adverse reactions or even toxicity, highlighting the need for strict quality control measures during processing and storage.
Several studies have demonstrated the wide range of pharmacological and biological activities of the different parts of Rhus coriaria. These activities include antioxidant, antimicrobial, antidiabetic, cardioprotective and antidyslipidemic, antinociceptive, neuroprotective, dental protection, and anticancer effects. The following body systems have received attention in the research literature:
The sterols and vitamins found in sumac contribute to immune system support, lipid profile regulation, and cardiovascular protection. Numerous in vitro, in vivo, and preclinical studies have demonstrated the efficacy of these compounds. Thus, Rhus coriaria should be considered not only for its traditional uses but also as a promising natural resource in modern functional food development and phytotherapy.
Health conditions that Sumac may help support.
Body systems that Sumac may help support.
Go back