Black walnuts are famous for their bold, natural taste and impressive nutritious profile.
They have been associated with many health benefits, for example, to reduce the risk of heart disease and weight loss.
Antioxidants and antibacterial compounds in their outer shells make them useful for the natural treatment of parasitic and bacterial infections.
This article discusses the benefits of black walnut, its properties and uses, as well as potential safety issues.
What are black walnuts
Black walnuts, or Juglans nigra, grow wild in the United States and are the second largest cultivated walnut in North America after English walnuts.
They consist of a core, a dry outer coating, known as a shell, and a hard shell.
A kernel is a part of a walnut that is usually eaten raw or fried and which can be pressed to produce oil. The shells contain antioxidants and are used in extracts and supplements for medicinal purposes, such as treating parasitic infections or reducing inflammation ( 1 ).
Black walnuts have a unique taste and aroma, which makes them more saturated and earthy than English walnuts. They are a popular addition to recipes such as pastries and desserts.
Black walnuts are the second most common walnuts and are valued for their bold and earthy taste. Inshell nutrients are mined and used in supplements.
Properties of Black Walnut
Black walnuts are rich in protein, healthy fats and many vitamins and minerals.
A serving of black walnuts in 1 ounce (28 grams) contains ( 2 ):
- Calories: 170
- Protein: 7 grams
- Fat: 17 grams
- Carbohydrates: 3 grams
- Fiber: 2 grams
- Magnesium: 14%
- Phosphorus: 14%
- Potassium: 4%
- Iron: 5%
- Zinc: 6%
- Copper: 19%
- Manganese: 55%
- Selenium: 7%
Black walnuts contain 75% more protein than English walnuts, which provide 4 grams of protein per 1 ounce (28 grams) serving. Protein is a nutrient that positively affects weight loss, control of blood sugar and a feeling of fullness ( 2 , 3 ).
They are low in carbohydrates, and most carbohydrates come from fiber, a nutrient that can also contribute to a feeling of fullness and weight control ( 4 ).
Walnuts are a good source of antioxidants – substances that can prevent or delay cell damage caused by unstable molecules called free radicals.
For example, they contain proanthocyanidins, which can protect against the harmful effects of the sun, improve vision and improve blood circulation ( 1 ).
They also provide alpha-linolenic acid (ALA), a type of omega-3 fatty acid. ALA is an essential fat, which means that your body cannot produce it, so you need to get it from your diet.
Black walnut is a food rich in nutrients – low in carbohydrates and high in protein, antioxidants and omega-3 fatty acids.
The use of black walnut
Fiber, omega-3 fatty acids and antioxidants in black walnuts provide various health benefits. In addition, the black walnut shell has unique antibacterial properties and is used in plant extracts and additives.
Black walnuts are nutritionally similar to English walnuts, which have been carefully studied for their health benefits.
May benefit heart health
Black walnuts, whose properties are provided by the content of healthy nutrients, are good for heart health. Nuts contain various nutrients and compounds that positively affect the heart system, including:
- Omega-3 fatty acids. May improve some risk factors for heart disease, such as high blood pressure and cholesterol ( 7 ).
- Tannins. Helps lower blood pressure and blood lipids, potentially improving heart health ( 8 ).
- Ellagic acid . May help prevent narrowing of the arteries caused by the accumulation of plaques, which can lead to heart disease ( 9 ).
A review of 13 studies showed that eating walnuts lowers total cholesterol and LDL (bad cholesterol). Moreover, studies show that eating walnuts improves blood vessel function and reduces the risk of blood clots, a major risk factor for cardiovascular disease ( 10 , 11 ).
May have anti-cancer properties
In addition, black walnuts contain flavonoid antioxidants, which have been shown to have beneficial effects on cancer of the lungs, breast, prostate, and colon ( 18 ).
They have antibacterial properties
Black walnut shells are rich in tannins – compounds with antibacterial properties ( 8 ). Therefore, black walnut, whose properties extend to counteract foreign microorganisms, is widely used in antiparasitic programs and protocols.
Tannins in black walnuts have an antibacterial effect, for example, against Listeria , Salmonella, and E. coli , bacteria that usually cause foodborne diseases ( 19 ).
An in vitro study showed that extracts of black walnut shells have antioxidant and antibacterial activity, preventing the growth of Staphylococcus aureus , a bacterium that can cause infections ( 20 ).
May help weight loss.
In fact, it has been found that walnuts maintain a full feeling in the stomach longer, which can help you naturally eat less, potentially contributing to weight loss ( 24 ).
In one three-month study, people who ate 1/4 cup (30 g) of walnuts daily experienced more weight loss than the control group — despite the extra calories of walnuts ( 25 ).
Black walnuts can have an antitumor effect and contribute to heart health and weight loss. In addition, plant compounds in the bodies have antioxidant and antibacterial properties.
How to eat black walnut
Herbal compounds in the shell of black walnut are extracted and used as additives in the form of capsules or liquid drops.
Due to its antibacterial properties, black walnut in the form of an extract is used in complex wormwood supplements. The wormwood complex is a tincture made of black walnut shell, a plant called wormwood and clove. This is a natural remedy for parasitic infections.
Moreover, body extract is used as a dye for hair, skin and clothing thanks to tannins, which have a natural darkening effect.
Both black walnut extract and complex wormwood supplements are widely available in stores and online.
However, research is limited to black walnut extract for these purposes, and more research is needed to confirm the benefits and side effects of black walnut supplements.
Black walnut shell extracts are popular in herbal medicine and are used to treat parasitic infections. It can also be used as a rinse and as a natural dye.
Black Walnut Safety
Although black walnuts have many health benefits, there are some safety aspects to consider when eating them or as an additive.
People with any allergies to nuts or tree nuts should not eat black walnuts or use supplements that contain them.
Supplements are not regulated by the Food and Drug Administration (FDA). Therefore, we recommend purchasing them from well-known brands that offer products that have been independently tested for safety and effectiveness.
Studies of the effects of black walnut supplements during pregnancy or breastfeeding are inadequate. And it is not known whether it is safe to take these supplements during pregnancy or breastfeeding.
In addition, tannins in black walnuts may interact with some medicines. It is best to consult a physician before taking black walnut extract if you are taking the medicine, are pregnant or breastfeeding ( 28 ).
People who are pregnant or breastfeeding, allergic to nuts, or taking certain medications should not take black walnut supplements without first consulting a doctor.
We examined black walnuts, properties and applications. Summarize.
Black walnuts are rich in omega-3 fatty acids and many vitamins and minerals. They can reduce the risk of heart disease and have anti-cancer and antibacterial properties.
The antioxidants and other plant compounds in black walnut shells make them a popular herbal supplement – although research is still limited.
Their nutrition profile and bold taste make black walnuts a healthy and tasty addition to your diet.