Walnut Oil: Are There Health Benefits?

Reviewed by Kathleen M. Zelman, RD, LD, MPH on November 17, 2022

Walnuts are one of the world’s healthiest nuts. They pack more nutrients and antioxidants than all other nut varieties.

Walnuts originated in ancient Persia before spreading across the world. They became a popular item on trade routes and were often gifted to royalty. The Romans thought the nut would counteract poison and treat skin conditions, while in Traditional Chinese Medicine they’re used to:

Modern scientists have found evidence to support many of these claims. While studies have traditionally focused on the benefits of the whole nut, newer research suggests that pressing it into walnut oil retains its health-boosting effects. 

Walnut oil is available at most grocery stores and is primarily used as a finishing oil to add flavor to recipes, sauces, and dressings. It’s can be used for pan frying, but try to avoid cooking it at too high of a temperature. At its smoking point, around 320°F, it can lose some nutrients and develop a bitter taste.

Nutrition Information

One tablespoon of walnut oil contains: 

  • Calories: 120
  • Protein: 0 grams
  • Fat: 14 grams
  • Carbohydrates: 0 grams
  • Fiber: 0 grams
  • Sugar: 0 grams

Walnut oil is a good source of: 

Walnut oil is also high in selenium. This antioxidant supports healthy thyroid function and may reduce your risk of cognitive decline, heart disease, and cancer.  

Potential Health Benefits of Walnut Oil

Walnut oil is a rich source of nutrients and antioxidants, some of which may even improve your memory and concentration.

Research shows that walnut oil has a number of other health benefits: 

Heart Health

Most of walnut oil’s fat content contains the omega-3 fatty acid called alpha-linolenic acid. This “good fat” can reduce your risk of developing heart disease by 10% when part of your daily diet. Scientists think this is because the omega-3s can lower cholesterol levels, helping to keep your arteries clear and well-functioning.

Walnuts also reduce levels of triglycerides, a type of fat associated with a higher risk of heart disease, heart attacks, and stroke. One study even found that walnut oil can help the body better deal with stress by keeping blood pressure levels steady and lowering strain on the heart. 

Lower Risk of Diabetes

Walnut oil is high in antioxidants that can lower blood sugar levels, reducing your risk of diabetes. Studies have found these antioxidants have anti-inflammatory effects as well.

Inflammation is our body’s natural response to stress and infection, but it can cause insulin resistance, which blocks the body’s ability to use sugars. This raises blood sugar levels, putting you at a higher risk of obesity and diabetes. 

Better Skin

Studies show that your body converts walnut oil’s fatty acids into compounds that make up your skin. Scientists believe that getting enough omega-3s and omega-6s in your diet — like those in walnut oil — may promote better skin health, heal wounds faster, and treat eczema, acne, and even some skin cancers.

You can also apply walnut oil topically. The oil’s anti-inflammatory and antioxidant effects may help slow signs of aging and treat conditions like psoriasis

Cancer Prevention

While more research is needed, studies show that walnuts' nutrients can slow the growth of cancer cells. Further research exploring the effects on humans is needed. The oil’s antioxidants help fight cell damage that scientists believe leads to cancer. Research shows a 15% lower cancer risk in people who eat an ounce of walnuts a day.

Potential Risks of Walnut Oil

Walnut oil is rich in nutrients, including omega-3s, which many diets often lack. However, like other cooking oils, it should be used in moderation to avoid adding too many extra calories to your diet and creating potential health risks like:


Walnuts can cause a severe allergic reaction for people with a nut allergy. Some people who are allergic to peanuts may experience an allergic reaction if they consume walnut oil.

Weight Gain

Walnut oil is high in calories. Use it sparingly when cooking, drizzling it on salads, or mixing it into a sauce to avoid unwanted weight gain. Excess weight can cause health problems such as cardiovascular diseases, some types of cancers, and other other serious medical conditions.

Medication Interaction

Walnuts can interact with some thyroid medications. Talk to your doctor to make sure walnut oil is okay to add to your diet.

Show Sources


American Institute for Cancer Research: “Walnuts: Support a Cancer-Preventive Diet.”

American Journal of Clinical Nutrition: “α-Linolenic acid and risk of cardiovascular disease: a systematic review and meta-analysis.”

Angiology: “Antihypertriglyceridemic effect of walnut oil.”

Clinical Dermatology: “Healing fats of the skin: the structural and immunologic roles of the omega-6 and omega-3 fatty acids.”

Critical Reviews in Food Science and Nutrition: “Health benefits of walnut polyphenols: An exploration beyond their lipid profile.”

ESHA Research, Inc., Salem, Oregon: “Walnut Oil.”

Food & Function: “Nuts, especially walnuts, have both antioxidant quantity and efficacy and exhibit significant potential health benefits.”

International Archives of Allergy and Immunology: “Walnut Allergy in Peanut-Allergic Patients: Significance of Sequential Epitopes of Walnut Homologous to Linear Epitopes of Ara h 1,2 and 3 in Relation to Clinical Reactivity.”

International Journal of Endocrinology and Metabolism: “The Effect of Walnut Oil Consumption on Blood Sugar in Patients With Diabetes Mellitus Type 2.”

International Journal of Molecular Sciences: “A Comprehensive Review on the Chemical Constituents and Functional Uses of Walnut (Juglans spp.) Husk.”

International Journal of Molecular Sciences: “Anti-Inflammatory and Skin Barrier Repair Effects of Topical Application of Some Plant Oils.”

Mayo Clinic: “Hypothyroidism diet: Can certain foods increase thyroid function?”

National Institutes of Health: “Selenium.”

Obesity Action: “Understanding Obesity and Type 2 Diabetes.”

Penn State University: “Walnuts, walnut oil, improve reaction to stress.”

PLoS One: “Rethinking the history of common walnut (Juglans regia L. in Europe: Its origins and human interactions.”

The Journal of Nutrition: “Acute Consumption of Walnuts and Walnut Components Differentially Affect Postprandial Lipemia, Endothelial Function, Oxidative Stress, and Cholesterol Efflux in Humans with Mild Hypercholesterolemia.”

The Journal of Nutrition: “Walnuts Have Potential for Cancer Prevention and Treatment in Mice.

The Journal of Nutrition, Health & Aging: “A cross sectional study of the association between walnut consumption and cognitive function among adult us populations represented in NHANES.”

The New England Journal of Medicine: “Guidelines for Healthy Weight.”

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