Thanks in part to heavy promotion on social media, walnuts have exploded in popularity in recent years: in 2010, global exports of walnuts were just over 160,000 tons; by the end of 2021, that number had reached 324,700 tons. According to one analysis, the global walnut market is now worth a staggering $8.8 billion and is expected to rise to more than $11 billion in 10 years’ time.
While there’s no denying their sweet taste, unique flavor, or the satisfying feeling of cracking a walnut, many people don’t realize just how nutritious walnuts are and how commonly they’re used in so many dishes. “Walnuts are incredibly versatile, and can be eaten raw by the handful, sprinkled on salads, cereal, or oatmeal, and are a popular addition to many baked goods recipes,” says Roxana Ehsani, RD, CS, RN.
What are Walnuts?
Walnuts are a nut that originated in what is now Iran about 7,000 years ago. Walnuts are grown in many countries, but the United States, China, Iran, Chile and Ukraine are the world’s largest producers. According to California Grown, nearly all of the walnuts grown in the United States come from California, as the state’s climate and fertile soil are ideal for growing walnuts.
Walnut trees can live up to 300 years, but most walnut orchards in California are replanted every 35 years because the trees become less productive as they age. There are many different types of walnuts around the world, but most people eat either black walnuts or English walnuts, although English walnuts are much more common. English walnuts are sometimes called Persian walnuts because they were cultivated early in the region.
Are walnuts good for you?
No matter which variety you try, walnuts are packed with nutrients: According to the USDA, walnuts contain calcium, vitamin B6, magnesium, riboflavin, niacin, folate, manganese, vitamin C, phosphorus, potassium, zinc, and a significant percentage of your daily iron needs.
“Walnuts are also a good source of alpha-linolenic acid (ALA), an essential omega-3 fatty acid,” says Christina Petersen, assistant professor of nutritional sciences at Texas Tech University. Higher ALA intakes are associated with better heart health and a lower risk of developing heart disease and type 2 diabetes, she notes. “Clinical trials have also shown that walnut consumption can lower LDL cholesterol levels, also known as bad cholesterol,” she adds.
Ehsani similarly praises walnuts for having “the highest ALA content of any nut,” adding that they’re also “a great source of protein, with a whopping 4 grams of plant-based protein per ounce. They also contain 2 grams of dietary fiber, which aids in gut health and promotes satiety,” she says.
The antioxidant and anti-inflammatory properties of walnuts have also been shown to improve brain function and slow age-related cognitive decline.
Are there any drawbacks to eating walnuts?
Despite these benefits, it’s best to eat walnuts in moderation. First, they’re high in calories — about 800 per cup in the shell — and excessive consumption has been linked to kidney stones in some people. This is because walnuts are high in oxalic acid, which can lead to calcium oxalate stones, the most common type of kidney stone. For this reason, the National Institute of Diabetes and Digestive and Kidney Diseases recommends that anyone who has had kidney stones avoid walnuts.
Of course, people with tree nut allergies should avoid walnuts, Ehsani warns, but for everyone else, “walnuts are a nutritious food and a great nut to include in a balanced diet,” she says.