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Cold Pressed Walnut Oil

Also known as: Walnut oil, cold pressed walnut oil, Persian walnut oil, Juglans regia L. oil

Overview

Cold pressed walnut oil is an edible nut oil mechanically extracted from walnuts (Juglans regia L.) without the use of heat or chemical solvents, which helps preserve its bioactive compounds. It is particularly rich in polyunsaturated fatty acids (PUFAs), including omega-3 alpha-linolenic acid (ALA) and omega-6 linoleic acid, as well as antioxidants and phytosterols. Primarily used as a dietary supplement, it aims to improve cardiovascular health, optimize lipid profiles, and potentially modulate inflammatory responses. Research on walnut oil is emerging, with moderate evidence, including randomized controlled trials (RCTs) and meta-analyses on walnut consumption, supporting its lipid-lowering effects. While direct evidence specifically on cold pressed walnut oil is more limited, existing studies show promising results, particularly in populations with hyperlipidemia.

Benefits

Cold pressed walnut oil offers several evidence-based benefits, primarily related to cardiovascular health. A meta-analysis of 61 controlled trials demonstrated that walnut consumption significantly reduces total cholesterol (TC) by approximately 8.85 mg/dL and LDL cholesterol (LDL-C) by about 5.68 mg/dL. Some analyses also indicated a reduction in triglycerides (TG) by roughly 10.94 mg/dL, highlighting its positive impact on lipid profiles. These moderate lipid reductions are considered clinically relevant for reducing cardiovascular risk. Secondary benefits include potential anti-inflammatory effects, as suggested by animal studies where walnut oil treatment reduced pro-inflammatory cytokines (IL-17, INF-γ) and increased anti-inflammatory IL-10 in multiple sclerosis models. For specific populations, a randomized controlled trial showed that 15 ml/day of cold pressed walnut oil for 90 days improved lipid profiles in type 2 diabetes patients with hyperlipidemia. The benefits typically manifest after about 3 months of consistent supplementation.

How it works

Cold pressed walnut oil exerts its effects primarily through its rich content of omega-3 alpha-linolenic acid (ALA) and omega-6 linoleic acid. These polyunsaturated fatty acids modulate lipid metabolism, leading to reduced LDL-C synthesis and improved lipid clearance from the bloodstream. The oil's antioxidants and phytosterols contribute by reducing oxidative stress and inflammation, which in turn supports improved endothelial function. At a molecular level, walnut oil influences lipid metabolism enzymes and can modulate inflammatory cytokine pathways, such as reducing pro-inflammatory IL-17 and INF-γ, while increasing anti-inflammatory IL-10, as observed in animal models. The cold pressing method of extraction is crucial as it preserves these bioactive compounds and the oil's beneficial fatty acid profile, thereby enhancing its bioavailability and efficacy within the body.

Side effects

Cold pressed walnut oil is generally considered safe, with no serious adverse effects reported in clinical trials at typical dosages of up to 15 ml/day. Mild gastrointestinal discomfort is a rare and not well-documented potential side effect. There are no significant drug interactions reported, however, caution is advised when used concurrently with anticoagulants (blood thinners) due to its omega-3 content, which can have mild antiplatelet effects. Individuals with a known allergy to tree nuts should avoid walnut oil due to the risk of allergic reactions. While data on special populations is limited, the oil appears safe for adults, including those with type 2 diabetes, as demonstrated in clinical studies. It is important to adhere to recommended dosages and consult a healthcare professional if any concerns arise, especially for individuals with pre-existing conditions or those on medication.

Dosage

The minimum effective dose for cold pressed walnut oil, particularly for lipid-lowering benefits, is approximately 15 ml per day. This dosage, equivalent to consuming 4–5 servings of whole walnuts per week, has been shown to improve lipid profiles in clinical trials. An optimal dosage, based on existing RCT evidence, is 15 ml daily for a duration of at least 3 months to observe significant benefits. The maximum safe dose is not definitively established, but typical culinary use of walnut oil is generally considered safe. It is recommended to take walnut oil with meals to enhance absorption and minimize any potential mild gastrointestinal discomfort. Cold pressed oil, whether in liquid form or capsules, is preferred as it preserves the beneficial fatty acids and antioxidants, thereby maximizing its efficacy.

FAQs

Is cold pressed walnut oil as effective as whole walnuts?

Yes, evidence suggests cold pressed walnut oil can replicate the lipid-lowering effects of whole walnuts due to its preserved fatty acid profile and bioactive compounds.

How soon do benefits appear after starting walnut oil supplementation?

Lipid improvements are typically observed after approximately 3 months of consistent daily intake of cold pressed walnut oil.

Is cold pressed walnut oil safe for individuals with diabetes?

Yes, studies have shown it to be safe and effective in improving lipid profiles in type 2 diabetic patients without adverse effects.

Does cold pressed walnut oil interact with medications?

No major interactions have been reported, but caution is advised if you are taking blood thinners due to its omega-3 content.

Research Sources

https://pmc.ncbi.nlm.nih.gov/articles/PMC9655834/ – This systematic review and meta-analysis of 61 controlled trials found that walnut consumption significantly reduced total cholesterol by ~8.85 mg/dL and LDL-C by ~5.68 mg/dL, and triglycerides by ~10.94 mg/dL. The study highlights the robust lipid-lowering effects of walnuts across diverse populations, supporting their role in cardiovascular risk reduction.
https://pmc.ncbi.nlm.nih.gov/articles/PMC5436098/ – This randomized, placebo-controlled trial investigated the effects of 15 ml/day cold pressed walnut oil for 90 days in hyperlipidemic type 2 diabetic patients. The study found significant improvements in lipid profiles (TC, LDL, TG) in the walnut oil group compared to placebo, demonstrating its efficacy and safety in this specific population.
https://taylorandfrancis.com/knowledge/Medicine_and_healthcare/Clinical_nutrition/Walnut_oil/ – This animal model study explored the anti-inflammatory effects of walnut oil in mice with experimental autoimmune encephalomyelitis. It reported that walnut oil reduced pro-inflammatory cytokines and improved clinical scores, suggesting a potential role in immune modulation and inflammation, though direct human extrapolation is limited.
https://academic.oup.com/nutritionreviews/article/81/1/26/6651942 – This source provides a general overview of the nutritional aspects and health benefits of walnuts, including their fatty acid composition and antioxidant properties. It supports the broader understanding of how walnut-derived products, like cold pressed oil, contribute to health, particularly in lipid metabolism and cardiovascular protection.