YahGarden

Herb library · Spice · Rhus coriaria

Sumac

The dried, crushed red berries of a Middle Eastern shrub, a sour spice sprinkled on kebabs, salads and za'atar. Small trials have tested it for blood sugar and cholesterol with mixed results. It is not poison sumac, a different plant.

Traditional use

Sumac berries have been an astringent medicine around the Mediterranean and in Persia since ancient times; Greek and Roman writers describe them, and Arab and Persian physicians used them for diarrhea, vomiting and the gums. The leaves were used to tan leather. Today it is mainly a kitchen spice and has been tested as a powder supplement for blood sugar and cholesterol.

Traditional energetics

What studies show

  • Limited

    Blood sugar: reviews disagree. A 2021 review of 6 trials (278 people) found no significant effect of sumac powder on fasting glucose, HbA1c or insulin. A 2026 review of 15 trials (917 people, 4 to 12 weeks) found improvements in blood sugar measures.

  • Limited

    Cholesterol and triglycerides: a 2018 review found only 4 small trials and no significant difference when they were pooled, and said no definite conclusion could be drawn. The 2026 review of 15 trials found improvements in blood lipids but no effect on inflammation markers.

Be careful of

Cautions

  • NoteCulinary sumac (Rhus coriaria) is not poison sumac. Poison sumac, poison ivy and poison oak (Toxicodendron) carry urushiol, which causes blistering skin rashes; swallowing it can cause a body-wide reaction that may be life-threatening. Buy sumac as a food spice, and never forage a sumac you cannot identify.
  • AmountThe trials gave sumac powder for 4 to 12 weeks. Longer use, or amounts beyond seasoning, has not been studied for safety in the sources used here.
  • InteractionIf you take medicine for diabetes or cholesterol, talk with your clinician before taking sumac as a supplement: some trials found lower blood sugar and lipids.
  • PregnancyNo pregnancy or breastfeeding safety information was found in the sources used here. Keep to cooking amounts.
  • Ask a clinicianTalk with a clinician or pharmacist before using this if you take prescription medicines, are pregnant or breastfeeding, or are giving it to a child.

From the old books

What herbals and dispensaries of the past printed. History, in their words.

“Abu Hanifeh in his “Book of Plants” says that Sumák has bunches of small, intensely red berries, and that it does not grow in any part of the land of the Arabs except Syria.”
William Dymock, C. J. H. Warden and David Hooper, Pharmacographia Indica (1890), vol. 1, p. 373. See the page of Pharmacographia Indica, vol. 1, p. 373 (opens in a new tab) · Read the full passage from Pharmacographia Indica, vol. 1, p. 373

Sources

  1. Sumac (Rhus coriaria L.) and human metabolic health: a systematic review and meta-analysis (Endocrinol Diabetes Metab, 2026) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  2. The effect of sumac (Rhus coriaria L.) supplementation on glycemic indices: a systematic review and meta-analysis of controlled clinical trials (Complement Ther Med, 2021) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  3. Effect of sumac (Rhus coriaria) on blood lipids: a systematic review and meta-analysis (Complement Ther Med, 2018) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  4. Toxicodendron toxicity (StatPearls, NCBI Bookshelf) — PubMed record (opens in a new tab) · NIH · read September 25, 2026

Reviewed September 25, 2026.