While there is some theoretical basis, the evidence for a direct and significant "memory improvement" effect in humans is insufficient, and it should not be considered a "smart drug" or a miracle supplement.
We can understand this from the following perspectives:
1. Theoretical Basis: Why is this claim made?
Walnut oil is rich in alpha-linolenic acid, a plant-based Omega-3 polyunsaturated fatty acid. Omega-3 (especially DHA) is an important component of brain cell membranes, crucial for maintaining the structure and function of nerve cells and promoting neuroplasticity. In addition, walnut oil contains antioxidants such as vitamin E and polyphenols, which may help combat oxidative stress in the brain.
Therefore, from a nutritional perspective, walnut oil is a high-quality edible oil beneficial to brain health.
2. Scientific Evidence: Support and Limitations
Animal Experiments: Some animal studies have shown that supplementing with walnuts or walnut extract can improve learning and memory abilities in older rodents. This provides a preliminary direction for research.
Epidemiological Observations: Some large-scale population observational studies have found that long-term, moderate consumption of nuts (including walnuts) is associated with better cognitive function and a reduced risk of Alzheimer's disease. However, this applies to the whole nut and is related to an overall healthy dietary pattern, and cannot be attributed solely to walnut oil.
Insufficient Human Clinical Research: Currently, there is a lack of high-quality, long-term, large-scale human clinical trials that directly prove that "consuming walnut oil can significantly improve memory in healthy individuals or patients." Existing human studies often have small sample sizes, short durations, or inconsistent conclusions. Many claims about "improving memory" directly cite studies on whole walnuts or Omega-3 fatty acids, rather than specifically referring to "walnut oil."
3. Core Issue: Walnut Oil ≠ Whole Walnut
This is the key point. Walnut oil is a fat extract from walnuts; it concentrates fat and fat-soluble nutrients, but loses other equally important beneficial components found in walnuts, such as:
Protein
Dietary Fiber
Most Vitamins and Minerals
Complete Phytochemical Complex
The nutrition community generally believes that eating whole walnuts is more beneficial than consuming walnut oil alone because of the synergistic effects between various nutrients.
4. Aspects to Watch Out For
High in Calories: Walnut oil is pure fat and extremely high in calories (approximately 900 kcal/100ml). Excessive consumption can lead to excessive calorie intake, which is detrimental to health.
Prone to Oxidation: High in unsaturated fatty acids, it is not heat-resistant and is not suitable for stir-frying or deep-frying. It is better suited for cold dishes, low-temperature cooking, or drizzling directly on dishes. Refrigerate after opening and use as soon as possible.
Exaggerated Claims: Many merchants overinterpret preliminary studies, promoting it as a "miracle oil" with therapeutic or significantly enhancing functions, which does not align with current evidence levels.
Conclusions and Recommendations:
As part of a healthy diet: Cold-pressed walnut oil can be used as a daily cooking oil, alternating with other healthy oils such as olive oil and flaxseed oil to supplement the body with Omega-3 and antioxidants, which are beneficial for long-term cardiovascular and brain health.
Don't Expect Immediate Results: Don't expect a significant improvement in memory after drinking walnut oil for a few days or weeks. Brain health requires long-term, comprehensive maintenance.
Whole walnuts are recommended: The Chinese Dietary Guidelines recommend consuming 50-70 grams of nuts per week (approximately 10 grams per day, equivalent to 2-3 walnuts). Eating walnuts directly is a more comprehensive and economical choice.
Improving memory requires a holistic strategy: A holistic lifestyle is more important than any single food:
Balanced diet: Follow the Mediterranean or DASH diet pattern, rich in vegetables, fruits, whole grains, high-quality protein, and healthy fats.
Regular exercise: Aerobic exercise effectively promotes blood circulation in the brain and the growth of new neurons.
Sufficient sleep: Sleep is crucial for memory consolidation.
Continuous learning and social interaction: Actively use your brain and maintain a vibrant social life.
Managing chronic diseases: Control blood pressure, blood sugar, and blood lipids.
In summary
Walnut oil is a good healthy oil, but evidence for its "improvement" effect on memory is currently limited. Incorporating it into a balanced diet is beneficial and harmless, but it should never replace healthy lifestyle habits and medical advice. For pursuing brain health, eating whole walnuts and adopting a holistic healthy lifestyle is far more effective and reliable than relying on any "superfood" or supplement.
