What is kalonji?
Kalonji is the seed of Nigella sativa, a flowering plant grown across South Asia and the Middle East. The seeds are small, black and angular, with a slightly bitter, peppery taste. They are a staple in Pakistani kitchens, sprinkled on naan and used in pickles (achar).
Kalonji in Prophetic medicine and Unani tibb
Kalonji holds a special place in Islamic tradition. A hadith in Sahih al-Bukhari describes black seed as containing healing for every illness except death. Because of this, it is known as habbatus sauda and has been part of tibb-e-nabawi (Prophetic medicine) for centuries.
In Unani tibb, kalonji is traditionally used to:
- support digestion and relieve gas and bloating
- support the respiratory system in cough and cold season
- support overall immunity and energy
- support healthy hair and skin, usually as oil
What does research say about kalonji?
Nigella sativa has been widely studied, mostly in laboratory and small human trials. Its main active compound, thymoquinone, has antioxidant and anti-inflammatory activity in lab studies. In humans, systematic reviews of small trials report modest improvements in:
- blood pressure
- cholesterol and triglycerides
- fasting blood sugar
The effects are small and the trials vary in quality. Kalonji can be a useful addition to a healthy diet, but it should never replace medicines prescribed for blood pressure, diabetes or cholesterol.
How is kalonji used?
- Seeds with honey: the most traditional method is a small amount of ground or whole seeds mixed with a spoon of honey, usually in the morning.
- In food: sprinkled on bread, salads, yoghurt and daal.
- Kalonji oil: a few drops in food or warm water, or applied to the scalp and skin. Cold-pressed oil is preferred.
Lightly roasting the seeds improves the taste. Follow product labels for oil and capsules.
How to identify real kalonji seeds
Kalonji is sometimes confused with, or replaced by, onion seeds (Allium cepa), partly because it is sold as "black onion seed" in some countries. Real kalonji seeds are:
- small, matte black, and angular with three or four sides, like tiny teardrops
- white inside when crushed
- aromatic when rubbed between the fingers, with a peppery, slightly oregano-like smell
Onion seeds are shinier, rounder, and smell mildly of onion. For oil, choose cold-pressed kalonji oil in a dark glass bottle. Strong-smelling, very cheap oil may be diluted with other oils.
Kalonji side effects and who should be careful
- As a food spice, kalonji is safe for most people.
- Diabetes and blood pressure medicines: larger amounts or oil supplements may lower blood sugar and blood pressure further, so monitor and speak to your doctor.
- Pregnancy: culinary amounts are fine, but avoid concentrated oil or supplement doses.
- Surgery: stop supplements two weeks before, as kalonji may slow blood clotting.
- Kalonji oil can cause skin rash in some people. Test on a small patch first.
