What’s smaller than a golf ball and jam-packed with protein, healthy fats, fiber, vitamins, minerals, and phytochemicals? The walnut, that’s what! In fact, walnuts are some of the most nutritious nuts on earth. So come with us as we dig into the ins and outs of walnut nutrition and discover why you should be enjoying more of this total body health food.
The Walnut: From Old World to New
Walnuts are members of the genus Juglans. While they’re considered tree nuts, they’re not nuts at all. In fact, they’re actually drupes—a group of stone fruits that includes cherries, peaches, and olives. Walnuts are also the oldest known tree food, having been enjoyed for at least 10,000 years.
There are many different types of walnuts, but the most common varieties are black walnuts and Persian walnuts. While black walnuts are native to North America, Persian walnuts originated in ancient Iran, where they were eaten by royalty. Persian walnuts eventually became more commonly known as English walnuts, when English merchant marines began to transport them for trade throughout the world.
This is the main reason that English walnuts are the variety most of us are familiar with—that and, as hard as the shell of an English walnut is, the shell of a black walnut is even harder.
This fact alone makes black walnuts more of a regional delicacy, though their ardent fans swear the nuts’ distinctive taste makes the extra work worthwhile. Each year they look forward to fall, when they gather the nuts from wild walnut trees and, with a combination of special equipment and sheer determination, crack the tough shells to get at the rich, bold meat within.
Walnut Nutrition Facts
While all nuts are a good source of many essential nutrients, walnuts have more antioxidants than any other nut. In fact, a handful of walnut halves contains almost twice as many antioxidants as the same amount of any other commonly eaten nut. And this has led experts to declare walnuts the healthiest nuts on earth.
And that’s not all.
Studies have also found that the antioxidants in walnuts are an astounding 4 to 15 times as powerful as vitamin E.
Moreover, walnuts are rich in both monounsaturated fats and polyunsaturated fats (omega-6 fatty acids and omega-3 fatty acids), including the essential fatty acids linoleic acid and alpha-linolenic acid (ALA).
You’re probably familiar with the EPA and DHA omega-3 fatty acids found in fatty fish. The ALA found in walnuts is similar, though it functions a little differently. This is because the EPA and DHA found in fish are the biologically active forms, while the ALA found in walnuts and other plant foods must first be converted into EPA and DHA before they can be used by the body.
The amount of ALA converted into EPA and DHA varies based on the individual, with an average of less than 10% converted into EPA and even less converted into DHA. However, consumption of ALA is associated with a lower risk of both heart disease and stroke, so it’s an important polyunsaturated fat to include in your diet.
Walnuts also contain relatively high amounts of numerous vitamins and minerals, including:
|Riboflavin||Vitamin E (especially gamma-tocopherol)|
Health Benefits of Walnuts
With all their healthy fats, vitamins, minerals, and phytochemicals, it should come as no surprise that eating walnuts—including their waxy, whitish skins, which contain the lion’s share of phytonutrients—is associated with a number of health benefits.
Studies have shown that people with low levels of omega-3 fatty acids are more likely to experience fatigue, cravings, and anxiety as well as depression and other mood disorders. However, a 2016 study looking at the effects of walnut consumption on mood in college students found that eating walnuts actually improved the moods of nondepressed male participants.
Several studies have also demonstrated that walnuts can improve memory and slow aging, likely as a result of their omega-3 fatty acids, which are needed to build and maintain nerve cell membranes and higher levels of which are associated with improved neuronal communication.
In addition, a 2011 study found that rats fed walnuts for 28 days showed improvements in both learning and memory, while other studies have demonstrated that the polyphenols in walnuts reduce oxidative stress and inflammation, helping to improve communication between neurons.
Studies have found that the heart-healthy polyunsaturated and monounsaturated fats in walnuts can help lower triglyceride and LDL cholesterol levels, both of which are risk factors for diseases—such as cardiovascular disease, stroke, and Alzheimer’s disease— commonly associated with the average American diet.
In fact, studies on the cardioprotective effects of walnuts have shown that the risk of coronary heart disease in those consuming walnuts more than 4 times per week is a whopping 37% less when compared with those who never or rarely consume the nuts.
Walnuts have also been found in several studies to decrease blood pressure—another well-known risk factor for heart disease and stroke.
Diabetes Prevention and Control
Consuming whole walnuts and walnut oil may help prevent and treat diabetes by reducing weight gain and controlling blood sugar. In a 2016 study, researchers found that 15 grams (approximately 1 tablespoon) of walnut oil every day for 3 months improved blood sugar levels in people with type 2 diabetes.
Having diabetes also gives an individual a higher chance of developing other risk factors for chronic diseases, including elevated cholesterol levels. However, studies have found that diabetics who eat walnuts have better lipid profiles than those who don’t.
The relatively high total fat content of walnuts is one reason they’re considered one of the most energy-dense foods out there. But consumption of walnuts isn’t associated with weight gain. On the contrary, people who include more walnuts in their diet are actually more likely to experience weight loss than those who don’t.
In an intriguing study from 2018, researchers found that obese patients who drank smoothies containing approximately 14 walnut halves for 5 days showed a decreased desire for high-fat foods when compared with the control group. When participants’ brains were scanned using MRIs, those who drank the walnut-containing smoothies showed increased activation in the part of the brain involved in appetite control.
Likewise, a 2009 study revealed that women who never or rarely ate nuts, including walnuts, had a higher risk of weight gain over an 8-year period than those who ate them 2 times a week or more.
The most abundant protein in the body is collagen. It’s also the main structural protein found in connective tissues, including bones and joints. One of the minerals in walnuts, copper, plays a key role in maintaining both collagen and elastin—another protein found in connective tissue. Without sufficient levels of this important mineral, the body can’t replace damaged connective tissue.
Walnuts are also rich in a number of other minerals necessary for the maintenance of bone health, including magnesium, phosphorus, manganese, and potassium, and eating more walnuts may help prevent the bone loss that leads to osteoporosis.
A 2018 study found that participants who ate 1-1/2 ounces of walnuts every day for 8 weeks had increased levels of beneficial gut bacteria and decreased levels of harmful bacteria. This is an important finding, as an imbalance in gut bacteria is linked to poor overall health, increased levels of inflammation, and greater risk of chronic disease.
The average American diet is one of many factors that’s been linked to the almost 60% drop in sperm counts over the past 40 years, but several studies have found that adding walnuts to even a typical Western diet can improve sperm quality and quantity.
The wide variety of polyphenols, tannins, and other phytochemicals in walnuts makes these nuts a potential powerhouse in the fight against cancer. Not only do many of these phytochemicals act as antioxidants, neutralizing the free radicals that cause oxidative stress and DNA damage, but their anti-inflammatory properties also mean they can help prevent the chronic inflammation that’s linked to a higher risk of cancer.
Studies conducted on mice have shown that diets high in whole walnuts are associated with a significant decrease in breast cancer growth rates when compared with similar diets containing the same amount of omega-3 fatty acids—a finding that suggests there are multiple compounds in walnuts that work synergistically to reduce cancer risk.
Similar findings have also been seen in studies looking at the link between walnut consumption and colon cancer and prostate cancer.
If you’re looking for the next superfood to add to your diet, look no further than walnuts. Whether you choose to munch on whole walnuts as a healthy pick-me-up, add a little walnut oil to your next vinaigrette, sprinkle some walnut halves in a crisp salad, mix up a heart-healthy smoothie, or crumble some of the tasty nuts into your favorite main course or dessert, all the things that make walnuts good to eat also make them good for you.
So what are you waiting for? Boost your total body health with some old-fashioned walnut nutrition today!