Walnuts
Overview
Walnuts provide plant-based omega-3 (ALA), polyphenols, and ellagitannins that can be converted to urolithin A by gut bacteria, supporting mitochondrial health and cognitive function. The Green Mediterranean Diet study showed greater visceral adipose tissue loss that tracked with higher total plasma polyphenols and with the microbiome-derived markers urolithin A (via ellagitannins: walnuts/pomegranate). Walnuts are part of the Mediterranean diet pattern and support BDNF expression through exercise and polyphenol synergy.
Food Context
Synergies
- Pair with other omega-3 sources for optimal DHA status (conversion from ALA is limited)
- Higher polyphenol intake and microbial diversity increase urolithin A production from ellagitannins
Sourcing
- Prefer fresh, well-sealed walnuts (or vacuum-packed) to reduce oxidation; rancidity risk increases with heat, light, and long storage.
Preparation
- Best consumed raw to preserve omega-3s and prevent oxidation
- Soaking may improve digestibility and reduce antinutrients
Essential Amino Acid Profile
Walnuts provide plant protein but are not a complete protein; lysine is typically limiting for nuts and seeds.
Protein pairing strategy:
Pair with legumes or grains to complete essential amino acid coverage.
Recipes
3 recipes containing this food
Ginger Yogurt and Blueberries
A polyphenol-rich breakfast bowl with high fibre, combining ginger, omega-3 nuts, blueberry polyphenols, and probiotic yogurt.
Mitochondrial Power Bowl
A nitrate-rich, polyphenol-dense bowl combining leafy greens, beets, berries, nuts, and early harvest olive oil
Rocket Lentil Avocado Midday Salad (Gut-Supporting)
Polyphenol-rich midday salad with quinoa or lentils, vegetables, avocado, and early harvest olive oil
Nutrient Tables (per 100 g)
Core nutrients
| Nutrient | Amount per 100 g | % RDA per 100 g |
|---|---|---|
| Energy | 656 kcal | — |
| Protein | 15.6 g | — |
| Total fat | 65.6 g | — |
| Saturated fat | 6.3 g | — |
| Carbohydrates | 12.5 g | — |
| Fibre | 6.2 g | — |
Key micronutrients
| Nutrient | Amount per 100 g | % RDA per 100 g |
|---|---|---|
| Iron | 2.8 mg | 15.6% |
| Zinc | 3.1 mg | 28.1% |
| Magnesium | 158 mg | 37.6% |
| Selenium | 17.5 µg | 31.8% |
| Calcium | 94 mg | 9.4% |
| Potassium | 438 mg | 12.9% |
| Copper | 1.6 mg | 176.7% |
Bioactive compounds
Values below are often from specialist compositional databases or literature, not the standard USDA panel. Asterisks (*) refer to source notes at the bottom of this section.
| Compound / class | Amount per 100 g | Notes |
|---|---|---|
| ALA | 9080 mg | — |
| Ellagitannins / total polyphenols | High among tree nuts (varies by batch) * | Ellagitannins feed gut-derived urolithins (e.g. urolithin A) in responders; assays differ (GAE/TEAC). |
Note: Bioactive-compound values vary substantially by cultivar, species, cocoa or oil percentage, processing, and brand formulation. Show quantitative values only where a defensible source exists; otherwise prefer qualitative presence statements or ranges in source notes.
- * Ellagitannins / total polyphenols: Qualitative ranking with high batch/cultivar variance; not a USDA standard nutrient row. Use for framework context, not precise comparison across studies.
Functional metrics
| Metric | Score | Notes |
|---|---|---|
| Total polyphenols (Folin proxy) | High | Walnuts consistently rank high in nut polyphenol surveys; matrix effects apply. |
Note: Functional-metric values depend strongly on assay method, processing, and product formulation. Use these as contextual metrics, not strict like-for-like nutrient equivalents.
Substances
Substances in this food: editorial (Overview / literature) plus analytical (nutrition table).
11 substances in this food
ALA (Alpha-Linolenic Acid)
Essential omega-3 precursor; limited conversion to DHA/EPA
Copper
Cofactor in redox enzymes; dopamine β-hydroxylase; iron metabolism interplay
Linoleic Acid (LA, n-6)
Essential omega-6; precursor to arachidonic acid and eicosanoids
Magnesium
Enzymatic cofactor (>300 reactions); neurotransmitters; mitochondria; redox balance
Manganese
Cofactor for MnSOD (SOD2); mitochondrial antioxidant defense
Iron
Oxygen transport; dopamine synthesis (tyrosine hydroxylase cofactor)
Zinc
Cofactor in neurotransmission and antioxidant enzymes; dopamine modulation
Selenium
Antioxidant enzyme cofactor (GPx); supports redox balance
Calcium
Bone health; neurotransmission; interacts with vitamin D and K2
Potassium
Electrolyte for nerve transmission, muscle function, and blood pressure regulation
References
- The Green Mediterranean Diet study showed greater visceral adipose tissue loss that tracked with higher total plasma polyphenols and with the microbiome-derived markers urolithin A (via ellagitannins: walnuts/pomegranate) Zelicha et al. 2022
- BDNF (modulator): Neurogenesis, synaptic plasticity, mood resilience; food sources include fatty fish, blueberries, turmeric, green tea, walnuts; exercise + omega-3 + polyphenol synergy boosts expression
- Walnuts mentioned as source of plant-based omega-3 (ALA) with limited conversion to DHA/EPA
- Higher polyphenol intake and microbial diversity increase urolithin A and related metabolites, supporting mitochondrial resilience and mitophagy and improving cognitive endurance