Black seed has anti-inflammatory and antioxidant effects and immune-modulating properties. Currently, the most well-studied benefits of black seed are for cardiovascular health and metabolic health.[1]
Black seed may improve glycemic control by lowering fasting glucose and hemoglobin A1c (HbA1c) by a clinically significant degree. This effect is the greatest in people with type 2 diabetes, but benefits are still observed in other relevant conditions like metabolic syndrome and nonalcoholic fatty liver disease (NAFLD).[2][3][4][5]
Black seed may also improve lipid profiles, including reduced triglycerides, low-density lipoprotein (LDL) cholesterol, and total cholesterol, and increased [high-density lipoprotein (HDL) cholesterol.[4][3][2] This lipid-modulating effect has not been found in people with NAFLD despite other observed benefits in this population (reduced levels of liver enzymes, C-reactive protein, and liver fat).[6]
Lastly, black seed may reduce blood pressure, and in people with overweight or obesity, it may cause slight reductions in weight and body mass index (BMI).[7][8]
Most of these effects have been observed in short-term studies (≤12 weeks), meaning the long-term effectiveness of black seed supplementation still needs to be determined. An exception to this is the effect of black seed on glycemic control, with benefits being maintained in some studies spanning 6 to 12 months.[4]