Walnut oil is, in fact, walnut kernel oil. It is an edible carrier oil made from the kernels of walnuts, including English walnuts, black walnuts and, more rarely, other varieties. Walnut oil can cause food allergies in those with walnut allergy, but is otherwise safe to eat and nutritious. Given its low smoke point, walnut oil is best used fresh or for light cooking at most. The benefits of walnut oil stem from its high unsaturated fatty acids content, being a high linoleic and alpha-linolenic oil and a good source of oleic acid. Walnut oil is good for the brain and cardiovascular system and a great cosmetic oil for hair, face and skin care in general.
What is walnut oil?
- Walnut oil is an oil made from walnut kernels.
- It is a carrier oil, non-fragrant and edible.
- It is a nut oil, made from walnuts. It can cause allergic reactions.
- It is a vegetal oil, made from a plant source.
- It is a food-grade or cooking oil, as in it’s edible, but preferred fresh on food since cooking heat alters its taste and flavor profile.
- It is a cosmetic oil meaning it can be applied safely on the skin or hair for various cosmetic uses, but not by people with walnut allergies who risk anaphylactic shock if they ingest or use the oil topically.
- It is a cold-pressed and also solvent-extracted oil and can be either unrefined or refined.
How to make walnut oil
Commercially available walnut oil is made either by cold-pressing, or expeller-pressing followed by solvent extraction, resulting in two main types of oil: unrefined and refined. A third type is obtained by roasting the kernels prior to extraction, to improve and accentuate the flavor profile.
- Cold-pressed, unrefined walnut oil demands the highest price because it is made by pressing or crushing walnut kernels to extract the oil in them. Cold-pressing is a mechanical means of oil extraction that uses no heat treatment and no solvents, but extracts less oil from the kernels than other methods, hence the higher price of cold-pressed oils in general. The resulting oil is likely filtered following the extraction in order to remove visible particles that could affect the aesthetics of the oil or promote fermentation, rancidification and spoilage, reducing shelf life.
- Refined walnut oil is typically expeller-pressed then solvent-extracted. During the first round of oil extraction, the kernels are mechanically pressed using an expeller press. This method usually involves heating above 100 degrees Celsius to allow the extraction of as much oil as possible. The resulting press cake, that is, the pressed, almost oil-less walnut kernel cake, is saturated with solvents to extract any remaining oils, after which the solvents are removed through heating from the resulting oil. The resulting oil is then filtered and likely further refined, as in bleached and deodorized to various degrees. Refining not only strips away some of the color, odor and flavor of the oil, but also makes it last longer, increasing shelf life and delaying rancidification.
- Roasted walnut oil is walnut oil made from roasted kernels. Unlike regular walnut oil which is a light amber color and has a mild nutty taste, toasted walnut oil is darker amber to brown colored with a more intense nutty flavor.
What is walnut oil made of?
The bulk of walnut oil is made from English walnuts, also known as Persian walnuts or Carpathian walnuts (scientific name: Juglans regia). This is the most common and readily available variety of walnuts, with the highest commercial value as a result of its larger, oil-yielding kernels as well as widespread natural occurrence and extensive cultivation. Even so, walnut oil is particularly expensive which partly explains its scarcity in home-kitchens around the world. There’s also walnut oil made from black walnuts (scientific name: Juglans nigra). And you can also make walnut oil from purple or red walnuts, a purple or red-colored variety of English walnut.
Walnut oil uses
Walnut oil boasts many uses, including culinary, cosmetic and industrial:
- Edible cooking oil, preferred fresh, but can also be lightly cooked (cooking heat affects flavor).
- Cosmetic oil, used for skin care, and face care in particular, but also hair care.
- Massage oil. While it can be used as a massage oil, walnut oil is generally too expensive which is why other cheaper types of oil are preferred.
- Carrier oil for essential oils. Not the first choice, but still a good carrier oil for diluting essential oils for aromatherapy and massage therapy.
- Paint oil. Walnut oil is actually a preferred choice for oil painting, along with linseed or flax seed oil, poppy seed oil, hemp, sunflower, safflower and other oils.
- Wood finishing. Walnut oil is actually a great oil for wood finishing, especially for wood objects that come into contact with food such as wooden cutting boards, bowls and kitchen utensils such as wooden spoons, forks or spatulas. The reason walnut oil is one of the best oils for the wood finishing of kitchenware is because it is non-toxic.
Walnut oil nutrition facts
Walnut oil boasts quite an impressive nutrition, its fatty acids profile alone commanding a range of health benefits. Walnut oil nutrition profile include fatty acids profile, vitamin and antioxidant profile:
- Walnut oil fatty acids profile per 100 g
- Linoleic acid (Omega-6): 50% to 58% of total fat content
- Alpha-linolenic acid (ALA Omega-3): 14% to 14.5% of total fat content
- Oleic acid (Omega-9): 13% to 20.5% on average, and up to 26.5% of total fat content
- Saturated fat (palmitic acid, stearic acid): 9% of total fat content
- Other fatty acids/lipids: 0.5% to 1%
Does walnut oil have oleic acid? Yes, it does. Actually, oleic acid is one of the most common fatty acids in vegetable oils and animal oils and fats. Versus olive oil which has an oleic content of 55% to over 80%, walnut oil is quite low in the monounsaturated fatty acid. Also see olive oil types by quality.
- Walnut oil nutrition facts per 100 g
- Energy: 884 kilocalories (kcal)
- Total fat content: 100 g
- Vitamin E (alpha-tocopherol): 0.4 mg (about 2.6% of daily requirements)
- Vitamin K: 15 micrograms (mcg) (about 12.5% of daily requirements)
- Choline: 0.4 mg (trace amounts)
Walnut oil properties
The properties of walnut oil and its fatty acids composition vary according to the variety of walnut used for oil extraction, choice of extraction method and other variables. Walnut oil is a:
- High unsaturated fat oil (85% of total fat content is made up of unsaturated fatty acids), also the reason why walnut oil is prone to turning rancid (unsaturated fats oxidize more readily)
- High polyunsaturated fat oil (polyunsaturated fat content ranging from 61.4% to 72%)
- High linoleic oil (between 50% and 58% of total fat content consists of Omega-6 fatty acids)
- High alpha-linolenic oil (between 10.4% and 14.3% of total fat content consists of Omega-3 fatty acids)
- Low oleic oil (between 13% and 26.6% of total fat content consists of Omega-9 fatty acids)
- Low saturated fat oil (with only around 9% saturated fat content, mostly palmitic and stearic fatty acids).
- Flavorful oil. Unrefined walnut oil is a flavorful oil, as opposed to neutral oils such as refined sunflower oil, corn or canola oil. Unrefined walnut oil has a mild nutty flavor profile, with a medium-intensity taste. Heating above the smoke point causes the oil to turn bitter.
- Low smoke point. The smoking point or smoke point of unrefined walnut oil is 120-160 degrees Celsius (250-320 degrees Fahrenheit).
What is walnut oil good for?
Walnut oil holds benefits for skin and hair in particular, but also boasts cardiovascular benefits and benefits for the brain and mental health. Here is what it’s good for:
- Benefits for the brain. Rich in fats, walnut oil is food for the brain, helping support cognitive functions and sustained intellectual activity.
- Combats brain fog. Brain fog, or mental confusion, is when your thinking seems clouded or hazy or when you can’t seem to focus. Including walnuts and even walnut oil in your diet is one of the best ways to combat brain fog as both are good brain foods.
- Good for mental health. A sufficient intake of healthy unsaturated fats from walnut oil and other foods benefits mental health and may help with symptoms of anxiety and even depression.
- Helps delay cognitive decline. Fats are physically part of our brain cells, whether it’s healthy unsaturated fats or cholesterol. Studies show getting enough fats in your diet helps delay cognitive decline and maintain cognitive function.
- Cholesterol-lowering properties. Walnut oil is rich in unsaturated fats such as Omega-3 fatty acids which promote cardiovascular health. Reasonable intake, as part of a varied and balanced diet, can help lower LDL (bad) cholesterol levels and possibly even raise HDL (good) cholesterol.
- Benefits for constipation. All edible oils have mild laxative properties. Including a little more fat in an otherwise low-fat diet can help relieve constipation.
- Benefits for the eyes. Walnut oil is good for the eyes. While it doesn’t have any vitamin A for eye health, it is all fat and helps with the absorption of both preformed vitamin A (retinol) from animal foods and pro-vitamin A antioxidants (carotenoids) from plant foods.
- Benefits for skin. Walnut oil can be used topically to moisturize skin, reduce dryness and associated discomfort, soothe irritation and soften skin.
- Potential benefits for eczema and dermatitis. Applying walnut, preferably unrefined, to the skin can help improve symptoms of eczema and dermatitis.
- Good for the face. Walnut oil is high in unsaturated fatty acids with anti-inflammatory and antioxidant properties and anti-aging action and thus one of the best oils to use for the face. The best type of walnut oil for skin care is unrefined. The vitamin E contain is too low to produce significant benefits.
- Potential benefits for acne. Studies show oils high in alpha-linoleic acid such as walnut oil and rose hip seed oil may help break up microcomedones and open pores, preventing acne.
- Benefits for hair. Walnut oil can be used for hair care. The fatty acids in it help control and repair damage, improving hair appearance, as well as restore shine to listless hair.