You'll see black seed oil, officially known as Nigella sativa, promoted as an antioxidant, a liver protector, an alternative remedy for cancer, an inflammation fighter and an aid in lowering your blood pressure. Many other naturally occurring dietary agents are used for some of the same purposes that black seed oil is marketed for, including curcumin, milk thistle and garlic. Always consult a doctor before adding an herbal remedy to your diet.
Black seed oil has several active ingredients, chief among them the antioxidant thymoquinine, which is considered a possible phyotochemical chemoprotective agent, meaning it might help prevent cancer. Turmeric, also called curcumin, is often promoted for the same purpose. Research suggests that turmeric can destroy certain cancer cells and reduce inflammation, according to "The Essential Herb-Drug-Vitamin Interaction Guide," by George T. Grossberg and Barry Fox. Turmeric also is promoted for preventing Alzheimer's disease and for treating bloating and heartburn. More research is needed, however, before firm conclusions can be drawn about any possible cancer chemoprotective agent, according to Edwina N. Scott, lead author for a 2009 review published in Cancer Prevention Research.
Black seed oil has possible protective effects for your liver, according to the Memorial Sloan Kettering Cancer Center. Milk thistle also is believed to promote liver function and have liver-protecting effects. It's frequently used to treat chronic hepatitis, which is liver inflammation, as well as liver cirrhosis, according to the National Center for Complementary and Alternative Medicine. While the experts at NCCAM say results from clinical trials of milk thistle have produced mixed results, Germany's Commission E, which is that country's regulatory body for herbs, has approved it for treating liver complaints.
Garlic is another herb promoted for its anti-inflammatory action, possible cancer protective properties and for its ability to lower blood pressure, all of which are uses black seed oil is marketed for. Early scientific evidence that taking garlic works to lower blood pressure -- if yours is high -- is promising, according to NCCAM. Commission E approves garlic to treat elevated blood pressure. A few studies also indicate that regularly consuming garlic can help cut your risk for cancer, but no clinical trials existed as of 2011, note the experts at NCCAM.
Whether you are looking to boost your health, prevent cancer or treat a medical condition by including black seed oil or another dietary agent into your regimen, it's important to realize that such foods can have side effects. For example, turmeric can cause diarrhea and nausea, gallbladder contractions and increase your risk of bleeding and bruising when taken with drugs such as warfarin. Milk thistle can have estrogen-like effects, so you shouldn't use it if you have a hormone sensitive condition such as breast cancer. It also can cause allergic reactions, vomiting or nausea, anorexia and menstrual changes. It also can lower blood sugar levels. Garlic can increase the risk for hypoglycemia when taken with certain drugs, reduce the effectiveness of other drugs and worsen gastrointestinal ailments. Black seed oil, at high doses, has the potential to cause kidney or liver damage. It may interfere with radiation therapy or chemotherapy drugs and may lower your blood pressure too much if taken in combination with drugs designed for fighting high blood pressure. It also may cause contact dermatitis.