20 Health Benefits Of Walnuts, Side Effects, & Cooking Tips

Medically Reviewed by Joel Kahn, MD
By Ravi Teja Tadimalla, Professional Certificate In Food, Nutrition & Health

Walnuts (Juglans regia) are high in antioxidants, proteins, dietary fiber, and essential omega-3 fatty acids. All these nutrients contribute to the benefits of walnuts. Walnuts can be black or brown, and both varieties have a wide range of health benefits. They may promote heart health, reduce cancer risk, support brain function, and reduce inflammation.

This article discusses the benefits of walnuts, their types, nutritional profile, how to use them, and their risks. Take a look.

Health Benefits Of Walnuts

1. May Promote Heart Health

Due to the high levels of omega-3 fatty acids, walnuts are very beneficial to the cardiovascular system. Eating a few walnuts a day may help reduce blood pressure too. Omega-3 fatty acids are known to reduce bad cholesterol in the body and encourage the production of good cholesterol. They also help reduce inflammation and boost blood vessel function (1),(2), (3). As a consequence, walnuts can promote heart health.

2. May Reduce Cancer Risk

Walnuts are rich in plant compounds like omega 3-fatty acids, polyphenols, and urolithins. These bio-active components may have anticancer properties.

Walnuts may reduce the risk of certain types of cancers such as that of breast, colon, and prostate (4). The American Association For Cancer Research stated that consuming a few walnuts each day may help reduce the risk of breast cancer (5).

3. May Support Brain Function

The omega-3 fatty acids in walnuts are also good for the brain. Having foods rich in essential fatty acids (like omega-3 fatty acids)may slow down cognitive decline (6).

In one study on the elderly, daily consumption of walnuts had shown improvement in cognitive function (7).

4. May Decrease Inflammation

Individuals with inflammatory diseases like asthma, arthritis, and eczema can benefit from walnuts due to the presence of essential fatty acids (8).

Walnuts may fight inflammation and reduce the risk of coronary heart disease (9). The polyphenols in walnuts may help in fighting inflammation too (10).

5. May Boost Immunity

Walnuts contain antioxidants that keep your immune system healthy and prevent the onset of diseases. Add some walnuts to your diet every day.

Walnuts are rich in vitamins and minerals such as copper and vitamin B6 that may boost immunity (11), (12).

6. May Improve Bone Health

Walnuts contain an essential fatty acid called alpha-linolenic acid. This acid and its compounds have been associated with stronger and healthier bones.

The omega-3 fatty acids in walnuts can also help. They help fight inflammation and decrease the subsequent bone resorption in humans (13).

7. May Provide Better Sleep

Walnuts have melatonin. This compound is associated with better sleep patterns (14). The omega-3 fatty acids may also keep the blood pressure low and help relieve stress. However, more research is needed in this regard.

8. May Benefit Pregnant Women

Having a walnut daily may greatly benefit pregnant women. Walnuts contain healthy vitamin B-complex groups like folates, riboflavin, and thiamin. These may promote health during pregnancy. However, more research is needed in this regard.

The folic acid in walnuts is particularly necessary for a pregnant woman and the fetus. Folic acid has many beneficial biological properties that may be helpful during pregnancy (15).

9. May Help Boost Digestive Health

Walnuts are rich in fiber. The nutrient helps in keeping your digestive system functioning properly. All humans require fiber on a daily basis to maintain their digestive health(16).

Having walnuts daily may help ease digestive problems and keep your bowels functioning properly. 

10. May Cure Fungal Infections

Anecdotal evidence suggests that black walnuts may help treat fungal infections. Candida growth, either in the digestive system or on the skin, can be highly aggravating.

These infections create a range of uncomfortable symptoms including itching and other allergies. Black walnuts could be as effective as certain treatments against fungal infections (17).

However, more research is needed in this regard.

11. May Help Detox The Body

There is limited research in this regard. Some claim the fiber in walnuts may help cleanse the system. The nutrient may also flush out harmful parasites.

Walnuts could be a healthy snack. However, do take them in moderation, as they also may cause allergies in certain individuals. Research is limited.

In the following section, we have discussed how walnuts may promote skin health.

Walnuts For Healthy And Beautiful Skin

12. May Delay Skin Aging

Walnuts can be good for the skin as they are packed with the B-vitamins. These vitamins may help ease stress and hence mood. Lower stress levels may promote skin health, though more information is warranted in this regard. Increased stress levels may lead to an earlier onset of wrinkles and other signs of aging.

The vitamin E (a natural antioxidant) in walnuts may help fight the free radicals caused due to stress. This can further help delay the aging process (18). 

13. May Help Moisturize Skin

Applying warm walnut oil may help ease dry skin. Anecdotal evidence suggests that walnut oil may help keep skin moisturized. It may nourish skin from within.

14. May Reduce Dark Circles

Regular application of warm walnut oil may lighten dark circles. The oil could soothe skin. It also may ease puffiness and relax your eyes. However, there is no direct research in this regard.

15. May Make Skin Glow

Anecdotal evidence suggests that walnuts may make your skin glow too. You may use a face pack for the same. This is how you can make and use one: 

How To Make A Walnut Face Pack

  • Add 4 walnuts, 2 teaspoons of oats, 1 teaspoon of honey, 1 teaspoon of cream, and 4 drops of olive oil in a blender.
  • Blend well to make a smooth paste.
  • Apply it to your face and let it dry completely.
  • Wash your face with warm water while massaging in a circular motion.

This face mask helps keep skin moisturized and also may delay the signs of aging.

Walnuts may also enhance hair health. In the next section, we have discussed certain important benefits of walnuts for hair. 

Walnuts For Healthier Hair

Factors like pollution, hectic lifestyle, and poor eating habits can damage hair and stress it out. You can have healthier hair by incorporating walnuts into your daily hair care regimen. Walnuts, whether consumed or applied externally as an oil, may keep hair strong and shiny.

16. May Strengthen Hair

Walnuts are good sources of fatty acids. These may strengthen hair follicles. In mice studies, those treated with walnut oil showed improvements in their hair color and texture. The mice also had reduced hair loss(19). More studies are needed to observe similar effects in humans.

17. May Help Treat Dandruff

Walnut oil is widely used for its moisturizing properties. It may help stimulate natural hair oils and help treat dandruff. Ethanol extracts of walnut leaves had shown anti-inflammatory activity. The leaves may also be used to treat dandruff (20). However, more information on walnuts is needed in this regard.

18. May Promote Scalp Health

Regular application of walnut oil may keep your scalp moisturized. This may help treat dandruff. However, more research is needed to further understand this benefit.

Anecdotal evidence suggests that walnut oil may have anti fungal properties. These may also help prevent infections triggered by ringworm. Concrete research is limited in this area.

19. May Enhance Hair Color

The husk of walnuts may act as a natural coloring agent. It may accentuate the natural highlights of your hair. The important proteins in walnut oil may also help enhance and maintain hair color.

20. May Reduce Chances Of Balding

Regular use of walnut oil has been reported to reduce chances of balding. However, there is no direct research to support this.

You may apply walnut oil to your scalp and hair at least thrice a week. You may also use it along with coconut or olive oils. However, if the oil causes any allergies, stop use and consult a doctor.

These are the benefits of walnuts. While most of them are yet to be confirmed by the medical community, including walnuts in your diet usually is healthy. The nuts are rich in several nutrients. In the following section, we will explore a few of them.

Nutritional Value*Of Walnuts

Walnuts are rich in fiber and low in carbs. These nuts are rich in fatty acids, vitamins, minerals, and plant components.

One ounce of walnuts (28 grams) provides 185 calories. It also contains 4 grams of protein, 18 grams of fat, and 3 grams of carbohydrates. Here are the other nutrients in an ounce of walnuts:

1.9 g of fiber

27 mg of calcium

44 mg of magnesium

98 mg of phosphorus

125 mg of potassium

1.3 µg of selenium

28 µg of folate

5 IU of vitamin A

0.7 mg of vitamin E 

*values sourced from USDA, nuts, walnuts, English

Though walnuts are replete with nutrients, taking them in excess can lead to adverse effects.

Serious Side Effects Of Walnuts

It is important to be aware of the side effects of walnuts. In some people, excess consumption can lead to allergies and drug interactions. Walnuts may also increase the risk of skin cancer in some. 

1. May Cause Allergic Reactions

Studies state that people who are allergic to nuts (pecans, in particular) should avoid black walnuts. This is because of the allergic reactions associated with them(21). The allergic reactions may include tightness in the throat or chest, hives, and difficulty breathing.

Walnuts may cause both primary and secondary allergies. Primary allergies involve the direct intake of walnuts or their products, which can lead to anaphylaxis. Secondary allergies involve pollen, which reacts with walnuts due to cross-reactivity and causes itching or swelling of the mouth (22).

2. May Increase The Risk Of Skin Cancer

Many people apply black walnut paste to their skin to treat minor cuts and eczema. However, black walnuts contain juglone, a chemical compound that has certain toxic properties (23). Though juglone is known for its anticancer properties, its pro-oxidant nature may increase the risk of cancer too. However, research is limited here.

3. May Cause Changes In Cellular DNA

According to a study published in the Toxicology and Applied Pharmacology Journal, the juglone in black walnuts may adversely affect fibroblasts (cells that produce collagen proteins). The studies were carried in rodents only (24).

The compound may decrease the levels of p53 (a type of skin protein) and cause damage to cell DNA. However, there is no concrete research in this regard.

4. May Cause Equine Inflammatory Disease

The extract of black walnuts was found to betoxic to horses (25). It caused an inflammatory disease called equine laminitis. The condition caused the white blood cells to accumulate in the hooves of the horse, leading to pain and lameness. Similar inflammatory conditions have not been observed in humans yet.

5. May Cause Iron Deficiency

Black walnut contains phytates. These have a strong effect on the body’s ability to absorb iron. Consuming walnuts when low on iron may lead to iron deficiency (26).

6. May Cause Liver Damage

An overdose of black walnuts may harm the kidneys (27). The juglone in the walnuts may have a role to play in this regard, though research is unclear. 

7. May Dry Up Body Fluids

Black walnuts may dry up bodily fluids like mucous. They may also cause dehydration during illness. However, research is limited in this area.

8. May Cause Skin Rashes

When applied topically, black walnuts may result in skin rashes. The chemical compounds found in the hull of the nut may irritate skin and lead to contact dermatitis (red-colored rashes) (28).

9. May Cause Birth Defects

The phytates in walnuts may cause iron deficiency (26). Pregnant women are more vulnerable to iron deficiency. The mineral is crucial for pregnancy. Its deficiency may lead to complications (29).

Iron deficiency during pregnancy may also cause miscarriage, though more research is needed in this regard.

10. May React With Other Medications

Black walnuts may interact with other medications that you may be taking (30). If you are on medications, consult your doctor before taking black walnuts or supplements containing them.

The tannins present in the hull may reduce the absorption of medications. However, more research is needed to support this claim.

Walnuts may cause adverse effects if consumed in excess. It also is important that you pick the right walnuts from the market. In the following section, we have discussed how you can select and store walnuts to get their maximum benefit.

How To Choose The Right Walnuts

Walnuts come in three different sizes – small, medium, and large. Check the shells thoroughly. Avoid shells that come with holes and/or cracks. If you are picking the shelled ones, ensure the meat within is plump and crisp. 

How To Store Walnuts

You can store walnuts in an airtight container in a dry, cool area, away from direct sunlight. Walnuts in the shell can have a shelf life of 3 months when stored this way.

Once the shell is removed, walnuts can be stored in the refrigerator for a maximum of six months. You can freeze walnuts in an airtight package and use them for a year without any damage. Walnuts generally absorb food flavors quite easily. While refrigerating or freezing, ensure they are kept away from foods such as onions, cabbage, or fish.

Recommended Serving

You can relish an ounce of walnuts daily. An ounce may include about 12 to 14 walnut halves.

Including walnuts in your diet and cooking is simple. You can check the following ideas.

Tips For Cooking

You can enjoy the benefits of walnuts by snacking on them directly or incorporating them as part of your diet. Here are a few tasty ideas for using these nuts:

  • Add 2 to 3 walnuts along with a banana and some yogurt for a healthy smoothie.
  • Transform walnuts into a delicious spread by toasting and then grinding them into a powder. Blend walnuts along with garlic, salt, lemon juice, olive oil, and a dash of pepper.
  • Prepare a delicious salad by mixing walnuts, diced apples, red and yellow bell peppers, and spring onions. Tossin a low-fat garlic vinaigrette dressing.
  • For a protein-packed meal, prepare a delicious dish with canned tuna, avocado, celery, and apples. Toss in toasted walnuts and flavor the dish with fresh lime juice.
  • Toss in a handful of crushed, toasted walnuts in your butter-free, sugar-free, whole grain, almond-oats cookie.
  • Walnuts can be paired with caramel, blue cheese, mushrooms, port, assorted salads, penne pasta, zucchini, raisins, and sherry.
  • Always shell walnuts or chop them only when you plan to eat. This will help retain the irfreshness.

Walnuts are nutrient-dense nuts with rich antioxidant properties. They also contain omega-3 fatty acids that contribute to many health benefits. They may promote heart health, reduce the risk of certain cancers, support brain function, decrease inflammation, and boost immune health. They also help delay skin aging, moisturize the skin, reduce dark circles, and promote scalp health. However, excess intake may cause allergies and drug interactions in some people. Hence, limit their consumption and consult your doctor if you experience any emergencies.

Frequently Asked Questions

What is the best time to eat walnuts?

Anecdotal evidence suggests that intake of walnuts along with breakfast may regulate blood pressure. Taking walnuts in the mornings seems to be ideal.

Is eating walnuts everyday good for you?

Yes, eating walnuts everyday is good for you. These nuts are rich in antioxidants and provide essential nutrients thatmay improve brain function, and potentially reduce the risk of heart disease and  cancer.

Sources

Articles on StyleCraze are backed by verified information from peer-reviewed and academic research papers, reputed organizations, research institutions, and medical associations to ensure accuracy and relevance. Check out our editorial policy for further details.
Was this article helpful?
thumbsupthumbsup
The following two tabs change content below.
Ravi Teja Tadimalla is an editor and a published author. He has been in the digital media field for over... more

Joel Kahn

(MD)
Joel Kahn, MD is a practicing cardiologist and a Clinical Professor of Medicine at Wayne State University School of Medicine.... more

LATEST ARTICLES