Black walnuts contain three main components that make them beneficial when consumed – antioxidants, polyunsaturated fats, and phenolic compounds. The walnuts also contain a range of other nutrients that includes fiber, protein, melatonin, and folate, which is a type of B vitamin.
Whether people eat them in nut form or take them as a supplement, black walnuts have many potential health benefits. It is also important to consider possible drawbacks as well.
Reduced risk for cardiovascular disease
Most experts agree that consuming nuts, including black walnuts, has well-established links to improving heart health.
Nuts, such as black walnuts, are high in fatty acids and antioxidants that can help to improve a person’s overall heart health.
According to the International Journal of Food Properties, numerous major studies have identified a positive correlation between higher nut consumption and lower risks for sudden cardiac death, heart attack, and heart disease.
Lowering blood pressure
Black walnuts contain arginine, which is an amino acid. Arginine turns into nitric acid in the body. Nitric oxide is a vasodilator, which means that it makes blood vessels larger. According to the International Journal of Food Properties, vasodilators can potentially lower blood pressure,.
The journal reports that black walnuts contain 3.62 grams (g) of arginine per 100 g of the food. This is slightly higher than English walnuts, which contain 2.28 g of arginine per 100 g of black walnuts.
Improved cholesterol levels
Walnuts contain phytosterols or plant sterols. Phytosterols are beneficial to the body because they limit the absorption of cholesterol in the body. This effect can help to lower a person’s cholesterol levels.
Black walnuts contain 37 milligrams (mg) more phytosterols than their English walnut counterparts, according to the International Journal of Food Properties.
Because doctors associate high cholesterol levels with greater risks for heart disease, keeping cholesterol levels low is essential for heart health.
Protection against neurological diseases
Black walnuts are rich in ellagitannins, which are a type of polyphenol. Ellagitannins have anti-inflammatory and free-radical-fighting properties in the body.
According to the journal Critical Reviews in Food Science and Nutrition, these compounds help prevent the onset and progression of neurodegenerative diseases in the body. Examples of these diseases include Parkinson’s disease, Alzheimer’s disease, and amyotrophic lateral sclerosis.
Reduced risk for liver cancer
A study in the 2011 issue of Pharmaceutical Biology found that cancer cells exposed to walnut extracts in a laboratory setting were effective in keeping cancer cells from multiplying.
The researchers found that the compounds chloroform and ethyl acetate were particularly effective at preventing liver cancer cells from multiplying. The researchers theorized that black walnut could have preventive and protective effects against liver cancer as well as some other cancer types.
Reduced risk for prostate cancer
Black walnuts are high in the compound y-tocopherol. Researchers have linked this nutrient with inhibiting tumor cell growth in prostate cancer cells, according to the International Journal of Food Properties.
While researchers have not been able to identify a specific dose or amount that has prostate cancer-protective properties, these compounds show promise as a method to reduce prostate cancer risk.
Additional reported benefits
Some researchers believe that black walnuts have many more health benefits. However, scientists have not studied these in any detail, so they are unable to confirm their effectiveness.
Examples of these potential benefits include:
- treating intestinal parasites
- healing skin wounds
- treating yeast infections
Some people believe that topical pastes of black walnut can treat skin conditions, such as warts, psoriasis plaques, and canker sores. However, researchers have not proven these properties to be true.
How to take and add to the diet
A person can simply add black walnuts to appetizers, salads, entrees, side dishes, and desserts.
Walnut shells are very thick, and some people may find them difficult to crack. However, shelled black walnuts are available.
Choosing walnuts that have undergone minimal processing and preparation will usually ensure they retain their nutritional profile.
Supplement manufacturers also sell black walnut as a single supplement or incorporate it with other herbs and fruits, such as garlic, cranberry, and Echinacea.
People should always check with their doctor before taking any new supplements. Always read the directions on the package carefully to ensure safe consumption.
Doctors generally consider black walnuts safe when people eat them in small amounts or take them as a supplement on a short-term basis.
Doctors do not know the long-term effects of taking black walnut supplements. Also, the U.S. Food and Drug Administration (FDA) do not regulate the supplements industry, so use discretion when buying supplements and always purchase them from a reputable company.
Some people report allergies after consuming black walnuts. Others report stomach irritation and upset after taking black walnut supplements or eating the nuts. Because doctors do not know much about the side effects of black walnut consumption, they recommend that breastfeeding or pregnant women do not take the supplements.
Black walnuts also contain substances called tannins that may decrease the body’s ability to absorb other medications. As a result, a person should not consume or take black walnut supplements at the same time as their regular medications. Waiting 1 to 2 hours between taking the supplement and taking other medicines is the best way to ensure that they will all work effectively.
Black walnut is a natural food product that has anti-inflammatory properties, which may help fight disease. A person can incorporate the nut into their diet or select a supplement that contains it.
However, always talk to a doctor before taking any new supplement, as it is possible that taking black walnut could interfere with how well the body absorbs certain medications.