Educational information, not medical advice — ask your doctor or midwife.
Sumac is a tart red spice made from the dried, ground fruit of the shrub Rhus coriaria. It tastes sour and lemony. Cooks across the Balkans, Turkey and the Middle East use it daily.
In Bosnian it is kiseli ruj. In Turkish and across the Balkans it is sumak. Besides the kitchen spice, it is sold as whole dried berries, capsules and liquid extracts.
Here is the honest verdict on the evidence. As a food spice, sumac is safe for most people. As a medicine, human proof is thin: a few small trials hint at small effects on blood sugar and blood fats.
Long use in folk cooking and folk medicine is not proof that it works. It is also not proof that strong capsules or extracts are safe. That point applies to every section below.
No one has shown, in people, how sumac acts on the body. Most of what you read about it comes from lab work.
Sumac is rich in tannins and other plant acids. In test tubes, these soak up free radicals, which are unstable molecules that can damage cells. That is a lab result, not a health outcome.
In cell and animal studies, sumac extracts appear to slow enzymes that break starch into sugar. If that happened in the gut, it might blunt the rise in blood sugar after a meal. Whether it does this in people at food-sized amounts is not established.
In laboratory tests, sumac extracts slow the growth of several bacteria and fungi. Whether that matters inside the human body, or on skin, has not been shown.
Animal work also suggests effects on blood fats and on markers of inflammation. Animal results often fail to repeat in humans. Treat them as leads, not findings.
Most people meet sumac as a coarse ground spice in a jar.
- Ground spice, sprinkled on meat, salad, rice, eggs and flatbread. - Whole dried berries, soaked and strained. - A sour cold drink made by steeping the berries in water.
- Part of the spice blend za'atar. - Capsules, tablets and powders sold as supplements. - Liquid or dry extracts, which are far stronger than the kitchen spice.
The gap between a pinch on a salad and a daily extract is wide. Nearly all the reassuring safety record belongs to the food use.
Sumac was a souring agent in the ancient Mediterranean long before lemons were common there. Roman and Greek cooks used it to sharpen food.
The Greek physician Dioscorides described sumac in the first century. Later writers recorded it for loose bowels, for gargles and as a wash for wounds. Balkan and Anatolian households kept it as both spice and simple home remedy.
The plant also had a trade use. Its leaves were rich in tannins and were used to tan leather, which is where the name coriaria comes from. These are historical records of how people used it, not records of whether it helped.
Call emergency services if your lips, tongue or throat swell, or if you struggle to breathe after taking sumac. That can be a severe allergic reaction.
Stop sumac and see your doctor if you get a spreading rash, hives or persistent itching.
See your doctor if you have diabetes and notice shaking, sweating, dizziness or confusion, which can signal hypoglycaemia (low blood sugar).
See your doctor if diarrhoea lasts more than two days, or if there is blood in your stool. Do not treat that at home with a spice.
In the United States, the United Kingdom and the European Union, sumac is an ordinary food spice. In the US it is treated as generally recognised as safe for food use. Capsules are sold as food supplements and are not approved to treat or prevent any disease.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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