WalnutIt’s a sizzling autumn afternoon in Meridian, California, where workers at family-owned Fedora Farms guide specialized machines along rows of trees laden with walnuts. A powerful harvesting machine clutches each tree trunk and shakes it violently. Walnuts tumble by the hundreds to the ground, the sound reverberating like a stampede. As the protective, chartreuse outer hulls of the walnuts are bruised they release a pungent herbal fragrance on the hot waves of afternoon sun. Other machines sweep along the rows, vacuuming the nuts from 400 acres of walnut crops. Harvesting the nuts from the trees is only the beginning of the meticulous process used to bring fresh walnuts to the market.

Worthy of its good repute, this noble nut has been a mainstay since about 10,000 BC, relied on for nourishment, healing, and disease prevention. When you spy a walnut in the orchard, it’s easy to see why the “doctrine of signatures” applies—a philosophy suggesting that a food resembling a body part offers special benefits to that region of the anatomy. Walnuts’ head-shaped hulls conceal a wrinkled nut within, the nut meat divided into right and left hemispheres, no less. It’s this appearance that prompted William Coles, an English naturalist during the Renaissance, to deem walnuts “very profitable for the brain.” He was right. A walnut split in half also looks like hearts, correctly pointing to its remarkable cardiac benefits.

“The walnut was the most important nut from a health standpoint in the ancient Mediterranean world,” says Kaley Todd, MS, RD, a spokesperson for California Walnuts, who adds that walnuts were used in the treatment of everything from inflammation, abscesses, and gangrene to bad breath and dog bites.

Walnuts’ medicinal and nutritional contributions are still highly valued. Having reviewed a number of studies on walnuts, Jessica Fishman Levinson, MS, RD, CDN, founder of Nutritioulicious, a nutrition counseling and consulting practice in New York City, explains, “Walnuts are a good source of protein, with 4 grams per 1-ounce serving, and dietary fiber, with 2 grams per 1-ounce serving. They’re also a good source of magnesium and phosphorus, two important minerals involved in bodily processes.

” Tasty walnuts are also a great source of antioxidants, including vitamin E, selenium, and polyphenols. “They are definitely considered a superfood!” Levinson says.

Christine Palumbo, MBA, RD, a member of the California Walnut Scientific Advisory Council, says it’s impossible to pinpoint what makes walnuts great. “Actually, it’s a mistake to try to tease out just what nutrient is responsible,” she says. “It may very well be its entire nutrient package acting in synergy that provides so many health benefits.”

What do walnuts do to contribute to good health?
  • They combat inflammation. Walnuts reduce inflammation, which helps fight disease. Although no single food is a “magic bullet,” cholesterol-free walnuts come pretty close when incorporated into an overall healthful dietary pattern such as the Mediterranean diet, Palumbo says. “Within that dietary pattern, walnuts are linked to reduced inflammation,” she says, “which is associated with reduced risk of heart attack and stroke as well as cancer, diabetes, and even Alzheimer’s disease.”
  • They enhance heart health. Research published in the Journal of Nutrition shows that a diet rich in walnuts, walnut oil, and flaxseed oil reduces arterial inflammation, measured by the effect on C-reactive protein and molecules that cause harmful plaque adhesion in blood vessels, says Levinson. In other studies, diets supplemented with walnuts result in a significantly greater decrease in total and LDL cholesterol.
  • They can improve blood flow for people with diabetes. Walnuts, says Levinson, have been shown to improve blood flow in adults with type 2 diabetes. “As part of a moderate-fat diet, they can lower the LDL cholesterol in people with type 2 diabetes.”
  • They can help fight cancer. “A study published in the September 2008 issue of Nutrition and Cancer showed the consumption of walnuts could slow the growth of breast cancer tumor cells in mice,” Levinson says. Researchers at the University of California, Davis found that walnuts also shrink prostate tumors in mice.
  • They can boost bone health. “A clinical research study published in January 2007 in Nutrition Journal found that bone health improved with alpha-linolenic acid consumption from walnuts and flaxseed,” Levinson says.
  • They can help you sleep. Walnuts, says Palumbo, are one of the few naturally occurring sources of melatonin, a a hormone made by the brain’s pineal gland that regulates the sleep-wake cycle and the body’s circadian rhythms.
  • They can sharpen your brain. “Preliminary research also points to cognitive effects, such as preventing age-related memory deficits and other mental decline in mice,” Palumbo says. “The omega-3 fats in walnuts influence the brain’s membrane, leading to improvement of mood and less depression.”

The culinary uses of walnuts are practically endless. Walnuts add crunch to a salad, a spread, or bread; add body to a pesto or chutney; and are wonderful paired with fruits in pilafs and pastries. Walnuts are what’s for breakfast, adding a nutritional punch to waffles, yogurt, and granola. They’re delicious in main dishes such as stir-fries, sautés, and casseroles. Inspired ideas include toasted walnuts with chile pepper, in herbed mashed potatoes, and as a perfect balance to salty cheese. They’re delightful in desserts, pairing well with chocolate and caramel or chopped and tossed on ice cream, cake, or pie.

“My favorite way to enjoy walnuts is to chop a small handful and put them into just-cooked oatmeal along with some raisins or blueberries,” Palumbo says. “I also like to fold some chopped walnuts into pancake batter along with blueberries, combine them with raisins and maybe a few milk chocolate chips for an easy snack mix, and make a banana split using a small whole banana split lengthwise down the middle, topped with yogurt and a couple tablespoons of chopped walnuts. I also love the thickness and protein content of Greek yogurt but need a little crunch, so I add some chopped walnuts.”

We’ve created simple recipes for walnut filled snacks and sweets, and Kevin Meehan, executive chef at Café Pinot in Los Angeles, provides some delicious recipes for savory flavors.

Buy them often. “Before I knew better, I would stock up on discounted walnuts during the holiday season and tuck them away for the next year,” says Christine Palumbo, MBA, RD. “Not a good idea! Due to their healthy amount of polyunsaturated fats, they can turn rancid, especially when stored at room temperature.”

Keep them chilled. Palumbo suggests keeping walnuts in the refrigerator like any other perishable food. Or, if you don’t anticipate using them within a couple months, place them in an airtight container and store in the freezer for up to one year.

Buy them natural. Jessica Fishman Levinson, MS, RD, CDN, says, “I recommend raw or toasted walnuts without added salt. Caramelized walnuts have a lot of added sugar, so it is best to keep those a treat.”

“One serving of walnuts, with 190 calories, is 1 ounce, which equals 1⁄4 cup shelled halves or pieces or 14 halves,” says Jessica Fishman Levinson, MS, RD, CDN, founder of Nutritioulicious.

“Walnuts are an excellent source of the healthy polyunsaturated fat,” says Fishman Levinson. “Specifically, they contain the highest amount of alpha-linolenic acid [ALA], which is a plant-based omega-3 essential fatty acid. A 1-ounce serving of contains 2.5 grams of ALA. Most nuts contain all or mostly healthy monounsaturated fat, but walnuts are comprised primarily of healthful polyunsaturated fats: 13 grams out of 18 grams total fat.”