Know2eat

Walnut oil

Juglans regia

What walnut oil has been studied for

2 associations assessed — 1 with at least some human evidence behind it. Strongest first.

  • 1 Limited
  • 1 Insufficient
4 things to know first — allergies, interactions and intake limits

About walnut oil

Oil pressed from walnut kernels, notable among culinary oils for carrying a meaningful share of the plant omega-3 alpha-linolenic acid alongside a larger share of omega-6 linoleic acid. Like all oils it is close to pure fat, so a per-100 g figure describes about seven tablespoons rather than a portion — the fatty-acid ratio is the informative number, not the total.

Also known as Huile de noix, Cold-pressed walnut oil

Heart HealthInflammation

The evidence in depth

Best supported: Limited

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how impressive the food is. How we rate evidence.

Blood lipid profile

Heart Health
Limited evidence

Some trials report lower LDL cholesterol when walnut oil replaces saturated fat in the diet, consistent with the general finding for unsaturated oils. Almost all of the walnut literature used whole walnuts, which also supply fibre, protein and polyphenols the oil does not, so the nut evidence should not be read across to the bottle.

What may be going on: Replacing saturated fatty acids with unsaturated ones increases hepatic LDL receptor activity and speeds LDL clearance from the blood.

Limited evidence. Early human work, or mostly lab and animal research.

1 source

Deep research mode adds each paper’s own conclusion and stated limitations.

Inflammatory markers

Inflammation
Insufficient evidence

Evidence is limited for walnut oil and inflammation. A handful of small trials of alpha-linolenic-acid-rich oils report modest changes in C-reactive protein, results are inconsistent, and the walnut trials that report clearer effects used the whole nut.

Insufficient evidence. Not enough human research to say anything useful yet.

No source is attached to this association yet, so it is rated insufficient by default. It is listed because people commonly ask about it — not because there is evidence for it.

Ask about Walnut oil

Ask about Walnut oil

Answers are written only from the entries on this page — the same nutrients, compounds, claims and citations you can read above. Nothing is added from outside the database, and every answer lists what it was built from.

AI explanations are not switched on for this site, so there is nothing to ask here. Everything above is read straight from the database and does not need them.

Key nutrients

Nutrient content per 100 grams
NutrientAmount% DV
Macronutrients
Calories884 kcal44%
Protein0 g0%
Total fat100 g128%
Carbohydrate0 g0%
Fibre0 g0%
Total sugars0 g—
Water0 g—
Fats
Saturated fat9.1 g45%
Monounsaturated fat22.8 g—
Polyunsaturated fat63.3 g—
Cholesterol0 mg0%
EPA (omega-3)0 g—
DHA (omega-3)0 g—
DPA (omega-3)0 g—
Linoleic acid (omega-6)52.9 g—
Vitamins
Vitamin A0 µg0%
Vitamin C0 mg0%
Vitamin D0 µg0%
Vitamin E0.4 mg3%
Vitamin K15 µg13%
Thiamin (B1)0 mg0%
Riboflavin (B2)0 mg0%
Niacin (B3)0 mg0%
Pantothenic acid (B5)0 mg0%
Vitamin B60 mg0%
Folate0 µg0%
Vitamin B120 µg0%
Choline0.4 mg0%
Minerals
Calcium0 mg0%
Iron0 mg0%
Magnesium0 mg0%
Phosphorus0 mg0%
Potassium0 mg0%
Sodium0 mg0%
Zinc0 mg0%
Copper0 mg0%
Selenium0 µg0%
Other measured compounds
Beta-carotene0 µg—
Alpha-carotene0 µg—
Lycopene0 µg—
Lutein + zeaxanthin0 µg—
Caffeine0 mg—
Ash0 g—

Nutrient values are per 100 g of the USDA reference entry named on this page and vary with variety, growing conditions, storage and preparation.

Source record: Oil, walnut (USDA FoodData Central, FDC ID 171030).

% DV uses the FDA Daily Values for adults and children aged 4 and over. A dash means no Daily Value has been established for that nutrient.

Bioactive compounds

Compounds present in meaningful amounts. Presence is banded rather than quantified, because whole-food levels vary enormously with variety, growing conditions, storage and preparation.

How preparation changes things

Only effects with real support are listed. If a preparation method is missing, it is because nothing dependable is documented — not because it makes no difference.

  • rawPreserves tocopherols and aroma compounds

    Used unheated as a finishing or dressing oil, walnut oil keeps both its aroma and its vitamin E fraction. Cold-pressed oil retains more of both than refined; refining removes colour, aroma and most of the minor components together.

  • friedIncreases lipid oxidation products

    Heating polyunsaturated oils to frying temperature, and especially reusing them, measurably increases aldehydes and other secondary oxidation products in the oil. The effect scales with polyunsaturated content, temperature and how many times the oil is reused.

Things to know

Allergies, interactions and intake concerns. Every food gets this section — a reference where everything is uniformly good is not a reference.

  • Allergy

    Tree nut allergen

    Walnut is a major regulated tree nut allergen. Cold-pressed and unrefined nut oils retain enough residual protein to have caused reactions, and anyone with a walnut allergy should avoid the oil regardless of how it is labelled.

  • Worth knowing

    Goes rancid quickly

    The polyunsaturated fraction that makes walnut oil interesting is also what makes it unstable. It oxidises faster than most kitchen oils, and a bottle that smells of old paint or crayon is already spoiled. Buy small, keep it in the fridge, and use it within a few months of opening.

  • Worth knowing

    Not a frying oil

    Unrefined walnut oil has a low smoke point and a high polyunsaturated content, a combination that favours the formation of aldehydes and other oxidation products when it is held hot or reused. It belongs in a dressing or over a finished dish.

  • Too much

    Energy density

    Pure fat, so it is among the most energy-dense things in a kitchen. Free pouring adds a lot of calories very quickly.