Nigella sativa is a plant that is sometimes used as a natural remedy to treat a wide variety of illnesses. Seeds and oil extracts from the plant are often sold as black cumin or black seed.
Experiments in test tubes and in laboratory animals have demonstrated that Nigella sativa may have anti-oxidant, anti-inflammatory, and other desirable properties. A few small studies in humans have demonstrated positive effects on memory, on blood pressure and on blood sugar in people with diabetes. More research is needed to better understand both the positive and negative effects of Nigella sativa on human health.
Nigella sativa products are marketed and sold as dietary supplements. As with all herbal and nutritional supplements, the US Food and Drug Administration does not regulate these products. The American College of Medical Toxicology recommends against the use of herbal and other dietary supplements (see the Choosing Wisely campaign.) One major concern is the lack of quality control in the products that make their way to consumers. Products may contain contaminants, including metals and prescription medications. Many herbal products have been documented not to contain any of the active ingredient. When they do contain the active ingredient, the dose can vary tremendously.
Until large, well-designed trials can illuminate the health benefits and adverse effects that result from use of Nigella sativa, and quality control of products sold to consumers can be assured, it is best to avoid use of these products. Most importantly, do not forego proven effective treatments for serious medical conditions because of an impression that ‘natural’ means safe.
Michelle Ruha, MD FACMT