Nigella sativa is a flowering plant native to Asia and the Middle East, where it has a long history of use in traditional herbal medicine.
Nigella sativa oil (NSO), also known as black seed oil, is an extract made from the plant’s seeds. The seeds contain several different vitamins and minerals, but thymoquinone is thought to be the most active component and is responsible for NSO’s main effects.
Read below to discover the science behind the potential health benefits, uses, and safety concerns of NSO.
Health Benefits of Nigella Sativa Oil
Researchers have demonstrated NSO may have antioxidant effects, meaning it’s able to combat the effects of oxidative stress – a collection of harmful reactions involving oxygen that cause cell damage.
For example, one study found thymoquinone extracted from Nigella sativa increased the production of antioxidant enzymes in rats.
Another study on human cells found that thymoquinone could decrease oxidative damage caused by hydrogen peroxide.
Helps to Regulate the Immune System
The immune system is the body’s natural defense system. When overactivated, immune cells may start attacking human cells inside the body, which can cause several health complications.
Evidence has found thymoquinone can decrease the action of immune cells called cytokines. This effect could help balance immune system dysregulation.
Furthermore, Nigella sativa has demonstrated usefulness in several animal models of inflammatory diseases.
NSO may help fight against viruses. For example, research has demonstrated Nigella sativa is useful in treating patients infected with hepatitis C.
Lowers Blood Cholesterol
Researchers have shown that Nigella sativa can decrease certain fats called cholesterols in the blood. This effect means NSO may be able to decrease the risk of heart disease caused by a build-up of cholesterol inside blood vessel walls.
Uses of Nigella Sativa Oil
Treatment of Allergies
Overactivity of the immune system is what causes allergic reactions. Because of its dampening effects on the immune system, NSO can help treat allergies and allergic conditions, such as asthma.
In one study on asthmatic adults, three weeks of daily Nigella sativa extract improved lung function and decreased the severity and frequency of asthmatic symptoms compared to a placebo.
Researchers have highlighted NSO as a helpful treatment for asthma and other allergic conditions.
Another study found supplementing with two 500mg NSO capsules per day improved asthma control scores and breathing in adult patients.
As well as asthma, researchers have highlighted NSO as a helpful treatment for other allergic conditions, such as rhinitis and eczema.
May Aid Weight Loss
In a study investigating the effects of NSO on weight loss, researchers gave overweight or obese women NSO or a placebo. After four weeks, the NSO groups had more significant reductions in body weight, BMI, waist size, and decreased appetite.
It’s unclear how NSO may impact weight loss. One reason may be that NSO contains compounds called polyphenols, which can help break down fat and inhibit the growth of fat cells.
However, as this review article indicates, some studies found NSO doesn’t affect weight loss, stating: “Although weight and waist circumference (WC) in 2 articles were reduced significantly, in 6 articles they were not.”
Could Help Treat Diabetes
Diabetes is caused when the body stops responding to insulin – a chemical messenger that increases glucose storage and breakdown. This insulin resistance causes diabetic patients to have abnormally high concentrations of blood sugar.
Evidence has demonstrated that NSO may decrease insulin resistance and increase insulin production, in turn helping to lower blood sugar in people with diabetes.
In line with this claim, an overview of seven different studies found NSO consistently helped improve blood sugar levels in diabetic patients.
Hair and Skincare
The antioxidant and anti-inflammatory properties mean Nigella sativa can protect against damage to the scalp, therefore, increasing hair growth and preventing hair from falling out.
In line with this claim, one study found that giving men and women coconut oil and a mixture containing NSO for 60 days reduced hair fall-out by 76%.
Furthermore, NSO has been effective in treating telogen effluvium – a scalp disorder characterized by hair fall-out and thinning of the hair.
The anti-inflammatory properties of NSO mean it may also be helpful for treating skin conditions caused by inflammation.
For example, researchers have demonstrated that NSO can reduce psoriasis plaques and acne. It can also reduce inflammation caused by bacteria in wounds, speeding up the process of wound healing.
May Protect Against Cognitive Decline
Because of the role of oxidative stress in age-related brain damage, the antioxidant properties of Nigella sativa mean it could help protect the brain against a decline in cognitive functions.
An experiment found that administering older adults daily capsules containing Nigella sativa for nine weeks improved their logical memory and attention scores.
The antioxidant properties of Nigella sativa mean it could help protect the brain against a decline in cognitive functions.
One study found that thymoquinone prevented nerve cell loss caused by beta-amyloid, a protein involved in the pathogenesis of Alzheimer’s disease.
In a rat model of Alzheimer’s disease, thymoquinone reduced brain damage in brain areas related to learning and memory and improved the rat’s scores in learning and memory tasks. However, similar results have yet to be replicated in humans.
Could Be Useful in Cancer Treatment
One research experiment found that thymoquinone, the major constituent of Nigella sativa oil, could initiate cellular suicide in pancreatic cancer cells, which may be useful at stopping the growth of cancerous tumors.
A group of scientists also demonstrated that alpha-hedrin, one of the key constituents in Nigella sativa, increased cellular suicide in the lung cancer cells of mice.
Furthermore, because of the antioxidant properties of Nigella sativa, it can help protect against oxidative stress caused by cancer cells, thus reducing cancer-related damage to health.
Despite the evidence supporting the potential of NSO for cancer, the lack of human research means it’s still largely unknown whether NSO would be safe and effective for cancer patients.
Side Effects of Nigella Sativa Oil
A review of various clinical trials observed that treatment with NSO caused no severe side effects in trial participants.
However, online sources suggest potential side effects from NSO include:
- Low blood pressure
- Itching and allergies (when applied to the skin)
In one 2013 case report, a diabetic patient was hospitalized with kidney failure after consuming Nigella sativa, suggesting NSO may have harmful effects on the liver. However, no similar cases have been reported to date.
Dosage Recommendations for Nigella Sativa Oil
A typical bottle of NSO will contain around 5g (5000mg) of Nigella sativa per teaspoon. A general dosage recommendation is, to begin with, half a teaspoon per day.
In one study, taking one teaspoon of NSO for eight weeks caused no negative side effects.
However, a large number of clinical trials have demonstrated that lower doses of NSO of between 0.5 and 3g are both safe and effective.
Nigella sativa is also sold in capsule form as well as an oil extract. Capsules typically contain around 500mg.
Nigella Sativa Oil Drug Interactions
Research has demonstrated that NSO can inhibit enzymes belonging to the cytochrome P450 (CYP450) family.
NSO could therefore increase the potency of medications which are normally broken down by CYP450 enzymes, including blood-thinners, antidepressants, and antiepileptics. However, there is no direct evidence to date showing that NSO has this effect.
Taking NSO alongside medications that lower blood pressure, such as antihypertensives, could potentially decrease blood pressure to dangerously low levels and should be avoided.
Additionally, taking NSO alongside medications that lower blood sugar levels, such as diabetic medications, could also decrease blood sugar levels to dangerously low levels and should also be avoided. Please consult with your physician before taking NSO if you are on any other medications or have any medical conditions.
Nigella Sativa Oil: Final Words
The antioxidant and anti-inflammatory effects of NSO give rise to several health benefits, including protection against cognitive decline and improving hair and skin health. NSO could also offer a natural remedy for various conditions, such as diabetes and allergies.
Although there appears to be little concern about any harmful side effects linked to NSO, users should still exercise caution. Every person is different and could have a different reaction to NSO.
As such, if you are considering using NSO, consult with your doctor first as they may be able to provide specialist advice suited to your own medical needs.
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