Provisions for the Brain: The Sacred Power of Walnuts

When I think of walnuts, I think of the brownies I bake every year on my birthday—and my favorite Persian dish, fesenjān, a sweet and sour stew with walnuts and pomegranate juice. In English, the walnut is also called “Persian walnut.” The word walnut literally means “foreigner’s nut.” In antiquity, the walnut was brought from Persia to Greece and spread through Europe by the Greeks and Romans. Eastward, it reached China via Afghanistan. This nut, among humanity’s oldest cultivated crops, is now grown in many more places. France, Italy and the United States are currently the largest producers.

Among the Greeks and Romans, the walnut tree was dedicated to the supreme god Zeus (Jupiter). Walnuts were seen as the food of the gods. The sacred connection is reflected in its botanical name Juglans regia, meaning “royal acorn of Jupiter.” The tree has long been associated with death and is widely planted in cemeteries, but the nut was also used as a fertility symbol at weddings, when walnuts were sprinkled over young brides.

Belgian professor of ethnobotany Marcel de Cleene noted that, in Europe and Latin-speaking countries, walnut trees were regarded as the favorite haunt of witches, who gathered beneath them on June 24, St. John’s Day. Brian Muraresku, author of The Immortality Key, also describes the walnut tree as a gathering place of wise herbal women, later known as witches.

The walnut was also considered an oracle tree in ancient Europe, its nuts believed to reveal prophecies about marriage and life. In Belgium, it remains customary to plant a walnut tree when a son is born. My mother planted one on our farm in Wallonia even before I was born. Interestingly, the names Wallonia and Wales both trace back to the word walnut. Walnut trees were also planted near farms, as the bitter substances of the leaves kept mosquitoes and flies at bay. Leaves were sometimes hung in cribs for the same reason.

Technically, walnuts are not true nuts. They do not meet the botanical definition: a fruit with one seed and a hardened shell, like a hazelnut. Walnuts are actually stone fruits, though they have long been called nuts.

According to traditional medicine, walnuts are used to strengthen the kidneys, lungs and intestines. They have warming properties and are believed to benefit libido. In Chinese cuisine, walnuts are among the most commonly used nuts, valued for their protein, fats and nutritional benefits.

And, as ancient healers once intuited, the walnut is a provision for the brain. According to the ancient Doctrine of Signatures, plants that resemble body parts were believed to have healing properties. The walnut, with its two lobes and convoluted surface, resembles the human brain—and in this case, the resemblance is more than symbolic. Rich in essential omega-3 fatty acids, walnuts support brain cell membranes; help reduce inflammation; and may contribute to protecting against degenerative conditions like Alzheimer’s, cardiovascular disease and arthritis.

Walnuts also contain the amino acid tryptophan, which the body converts into serotonin, the “happiness hormone” that helps support mood. They are high in antioxidants and fiber, and their vitamin E may support reproductive health and overall cardiovascular wellness.

A well-known home remedy for colds and digestive issues involves soaking young walnuts with their green husks in brandy, often with cloves and cinnamon. The walnut tree itself—with its aromatic, lanceolate leaves and iconic green-then-black husk—has long been revered for its healing properties.

For most adults, the recommendation is to eat one handful (about 25 grams or 0.8 ounces) of unsalted nuts per day. Walnuts are particularly satisfying and help curb hunger for hours. A good-quality walnut oil also makes a flavorful and brain-healthy vinaigrette.

Whether baked into brownies, stirred into fesenjān or simply eaten as a snack, walnuts carry with them a long and sacred history—and powerful nourishment for the mind.

FESENJĀN WITH CHICKEN OF THE WOODS
MUSHROOMS, POMEGRANATE AND WALNUT

YIELD: 4 SERVINGS

3.5 oz shelled walnuts

2 Tbsp olive oil, plus extra

1 red onion, chopped

2 garlic cloves, finely chopped

½ Tbsp cinnamon powder

½ Tbsp cayenne pepper

7 oz cooked chickpeas

8.5 oz vegetable stock

3 Tbsp pomegranate syrup

1 Tbsp maple syrup

Fine sea salt and freshly ground black
  pepper

1 lb chicken of the woods mushrooms 

Seeds of ½ pomegranate

Cooked rice for serving

Heat a dry large skillet over medium-high heat, and add the walnuts. Toast for a few minutes until golden brown.

Briefly grind the walnuts in a food processor to a fine crumb.

In a tall, thick-bottomed pan, heat the olive oil over medium-high heat. Add the onion and garlic and sauté for about 5 minutes, until they begin to brown. Add the cinnamon powder and cayenne pepper, and sauté briefly. 

Add the nut crumbs, chickpeas, vegetable stock, pomegranate syrup and maple syrup. Bring to the boil, then cover with a lid. Let simmer for about 10 minutes until thickened. Season to taste with salt and pepper.

Meanwhile, brush or rub the mushrooms clean. Heat a splash of olive oil in a skillet over high heat, and briefly fry the mushrooms until just al dente. 

Slice the mushrooms and place them on top of the nut stew. Sprinkle with the pomegranate seeds. Serve with rice.

Wouter Bijdendijk is a Dutch anthropologist with more than 20 years of global fieldwork in ethnobotany and herbal medicine. For more information, visit WouterBijdendijk.org.
Joris Bijdendijk is a Michelin-starred chef and author, known for RIJKS at the
Rijksmuseum and his restaurant Wils, in Amsterdam. For more information, visit JorisBijdendijk.nl.

Adapted from Plant Power: Heal Yourself with Medicinal Mushrooms, Roots,
Flowers, and Herbs by Wouter and
Joris Bijdendijk (Findhorn Press,
October 2025; ISBN 9798888502693).